By focusing on the vulnerability of the structure of marine equipments, together with considering the randomness of meta-ocean load in statistics, a kind of analytical method of fatigue characteristics of marine struc...By focusing on the vulnerability of the structure of marine equipments, together with considering the randomness of meta-ocean load in statistics, a kind of analytical method of fatigue characteristics of marine structure based on full- scale and actual measurement of prototype is proposed. On the basis of short-term field measurement results of structural response, research is carried out on the fatigue analysis of hinge joints at the upper part of the Soft Yoke single point Mooring System (SYMS) by simultaneously monitoring the environmental load and considering the design criteria of offshore structure. Through analysis of finite element modeling, the time-histories of typical stress response are obtained, and then the assessment of fatigue damage at key hinge joints is conducted. The simulation results indicate that the proposed method can accurately analyze the fatigue damage of offshore engineering structure caused by the effect of wave load. The present analytical method of fatigue characteristics can be extended on other offshore engineering structures subjected to meta-ocean load.展开更多
In the terahertz band,the dispersive characteristic of dielectric material is one of the major problems in the scaled radar cross section(RCS)measurement,which is inconsistent with the electrodynamics similitude deduc...In the terahertz band,the dispersive characteristic of dielectric material is one of the major problems in the scaled radar cross section(RCS)measurement,which is inconsistent with the electrodynamics similitude deducted according to the Maxwell’s equations.Based on the high-frequency estimation method of physical optics(PO),a scaled RCS measurement method for lossy objects is proposed through dynamically matching the reflection coefficients according to the distribution of the object facets.Simulations of the model of SLICY are conducted,and the inversed RCS of the lossy prototype is obtained using the proposed method.Comparing the inversed RCS with the calculated results,the validity of the proposed method is demonstrated.The proposed method provides an effective solution to the scaled RCS measurement for lossy objects in the THz band.展开更多
Objectives: This study was designed to test and validate the new LPD scale in a home care setting. The specific objectives are to validate the LPD scale for subjects cared for at home;and to compare LPD to the Braden ...Objectives: This study was designed to test and validate the new LPD scale in a home care setting. The specific objectives are to validate the LPD scale for subjects cared for at home;and to compare LPD to the Braden scale for internal validity. Method: This multicenter, cross-sectional study was conducted in the domestic environment of subjects cared for Home Care services from North to South of Italy. Data collection lasted 8 months, between June 2018 and September 2020, and consisted of the simultaneous compilation of the new LPD, and the Braden scale. Home Care Expert nurses could interface with the recruited subjects and/or caregivers. The parameters considered to validate the new scale were sensitivity (Se), specificity (Sp), positive predictive values (PPV), odds ratio (OR), and the area under the receiver operating characteristic (ROC) curve. Results: Of the 679 recruited subjects, 63.2% were women, and more than 50% did not have a pressure ulcer. 48.2% of the sample aged over 85 years old;69% was affected by multiple disease, and 76.6% took a lot of drugs. 91.6% of the subjects were affected by a partial or total functional dependency. Around 50% of subjects presented double incontinence, and 43% were conscious and collaborated. 85.4% of subjects lived in a healthy environment. The predictive validity parameters showed: Se 77.25%, Sp 84.04%, PPV 91.37%, and the area under the curve (AUC) 0.88% with a confidence interval (CI) 95%. These values mean a moderately accuracy of the test. Conclusions: The new LPD scale has demonstrated a good capacity for identifying the subjects at risk of pressure ulcer and had a better discriminatory power rather than Braden scale.展开更多
There are several shape measures for quantitative variables, some of which can also be applied to ordinal variables. In quantitative variables, symmetry, peakedness, and kurtosis are essential properties to evaluate t...There are several shape measures for quantitative variables, some of which can also be applied to ordinal variables. In quantitative variables, symmetry, peakedness, and kurtosis are essential properties to evaluate the deviation from assumptions, particularly normality. They aid in selecting the most appropriate method for estimating parameters and testing hypotheses. Initially, these properties serve a descriptive role in qualitative variables. Once defined, they can be considered to check for non-compliance with assumptions and to propose modifications for testing procedures. The objective of this article is to present three measures of the shape of the distribution of a qualitative variable. The concepts of qualitative asymmetry and peakedness are defined. The measurement of the first concept involves calculating the average frequency difference between qualitative categories matched by frequency homogeneity or proximity. For the second concept, the peak-to-shoulder difference and the qualitative percentile kurtosis are taken into consideration. This last measurement is a less effective option than the peak-to-shoulder difference to measure peakedness. A simulated example of the application of these three measures is given and the paper closes with some conclusions and suggestions.展开更多
There are several shape measures for quantitative variables, some of which can also be applied to ordinal variables. In quantitative variables, symmetry, peakedness, and kurtosis are essential properties to evaluate t...There are several shape measures for quantitative variables, some of which can also be applied to ordinal variables. In quantitative variables, symmetry, peakedness, and kurtosis are essential properties to evaluate the deviation from assumptions, particularly normality. They aid in selecting the most appropriate method for estimating parameters and testing hypotheses. Initially, these properties serve a descriptive role in qualitative variables. Once defined, they can be considered to check for non-compliance with assumptions and to propose modifications for testing procedures. The objective of this article is to present three measures of the shape of the distribution of a qualitative variable. The concepts of qualitative asymmetry and peakedness are defined. The measurement of the first concept involves calculating the average frequency difference between qualitative categories matched by frequency homogeneity or proximity. For the second concept, the peak-to-shoulder difference and the qualitative percentile kurtosis are taken into consideration. This last measurement is a less effective option than the peak-to-shoulder difference to measure peakedness. A simulated example of the application of these three measures is given and the paper closes with some conclusions and suggestions.展开更多
This study investigates how traditional Chinese values influence Chinese consumer behavior directly and indirectly through the impact on people's lifestyles and perceived values.The empirical research is conducted...This study investigates how traditional Chinese values influence Chinese consumer behavior directly and indirectly through the impact on people's lifestyles and perceived values.The empirical research is conducted in the context of the mobile phone market in Shanghai.The study establishes measurement scales of Confucian value,lifestyle,and customer perceived value for Chinese market.Relationships of multiple factors are tested in the structural equation model and their impacts on consumer behavior are elaborated.Findings indicate that Confucian values not only have a direct impact on Chinese consumer behavior but also indirectly influence this behavior through impacting people's lifestyles and perceived values.展开更多
The corticoreticular tract (CRT) is known to be involved in walking and postural control. Using diffusion tensor tractography (DTT), we investigated the relationship between the CRT and gait dysfunction, includ- i...The corticoreticular tract (CRT) is known to be involved in walking and postural control. Using diffusion tensor tractography (DTT), we investigated the relationship between the CRT and gait dysfunction, includ- ing trunk instability, in pediatric patients. Thirty patients with delayed development and 15 age-matched, typically-developed (TD) children were recruited. Fifteen patients with gait dysfunction (bilateral trunk instability) were included in the group A, and the other 15 patients with gait dysfunction (unilateral trunk instability) were included in the group B. The Growth Motor Function Classification System, Functional Ambulation Category scale, and Functional Ambulation Category scale were used for measurement of functional state. Fractional anisotropy, apparent diffusion coefficient, fiber number, and tract integrity of the CRT and corticospinal tract were measured. Diffusion parameters or integrity of corticospinal tract were not significantly different in the three study groups. However, CRT results revealed that both CRTs were disrupted in the group A, whereas CRT disruption in the hemispheres contralateral to clinical mani- festations was observed in the group B. Fractional anisotropy values and fiber numbers in both CRTs were decreased in the group A than in the group TD. The extents of decreases of fractional anisotropy values and fiber numbers on the ipsilateral side relative to those on the contralateral side were greater in the group B than in the group TD. Functional evaluation data and clinical manifestations were found to show strong correlations with CRT status, rather than with corticospinal tract status. These findings suggest that CRT status appears to be clinically important for gait function and trunk stability in pediatric patients and DTT can help assess CRT status in pediatric patients with gait dysfunction.展开更多
High performance Dynamic Light Scattering (DLS) has been used to determine the hydrodynamic di-ameters of CdSe nanocrystals as well as CdSe cluster molecules in a size range of 1 to 10 nm (Eichh鰂er et al., 2001). The...High performance Dynamic Light Scattering (DLS) has been used to determine the hydrodynamic di-ameters of CdSe nanocrystals as well as CdSe cluster molecules in a size range of 1 to 10 nm (Eichh鰂er et al., 2001). The method enables the determination of their particle size, including their ligand shells, in solution. The results are consistent with the blue shift of the absorption bands, as well as Transmission Electron Microscope (TEM) experiments. The sizes of the cluster molecules were estimated from space filling models constructed from the results of a single crystal X-ray structure determination. DLS gave comparable results for the size of both types of compound, indicating that it is potentially an important additional measurement technique to TEM, which uses harsh measurement conditions, and to powder X-ray diffraction, which is difficult to interpret below 5 nm.展开更多
Diving is a recreational activity of growing significance in many countries.In the recreational SCUBA diving industry,a liveaboard service offers tourists to stay on board for several nights and that allows time to tr...Diving is a recreational activity of growing significance in many countries.In the recreational SCUBA diving industry,a liveaboard service offers tourists to stay on board for several nights and that allows time to travel to more distant dive sites.SCUBA diving belongs to an adventure tourism,while cruise is much more leisure tourism activity.However,they share a similar travel mode,so it is very interesting to find the reason behind.Do cruise tourists be the potential diving tourists?The paper adopted the cruising motivation scale for diving tourists to develop a scale for SCUBA divers’motivations of liveaboard.Convenience sampling was used to select participants for the study.After exploratory factor analysis(EFA),the results showed that there were six dimension of SCUBA divers’liveaboard motivation,and the added dimension of divers’preference was valid.Finally,a measurement scale of SCUBA divers’liveaboard motivation was proposed in this study,and the discussion and implication were also presented in the paper.展开更多
Many impulsive phenomena from physics, control theory, and economics urge us toinvestigate measure large scale systems. In this paper, the variation of parameters formulaof the large scale systems containing measures ...Many impulsive phenomena from physics, control theory, and economics urge us toinvestigate measure large scale systems. In this paper, the variation of parameters formulaof the large scale systems containing measures is established. By means of inequality methods and comparison theory, the stability, uniform stability, asymptotic stability, uniformasymptotic stability, and exponential stability properties of linear measure large scale systems are studied.展开更多
Objective: To formulate the standard measuring tool for the evaluations on fire-heat syndrome in oral cavity by means of Chinese medicine (CM). Methods: The measuring scale for fire-heat syndrome in the oral cavit...Objective: To formulate the standard measuring tool for the evaluations on fire-heat syndrome in oral cavity by means of Chinese medicine (CM). Methods: The measuring scale for fire-heat syndrome in the oral cavity by means of CM was investigated by symptom collection, item pool formulation, item selection, pre-investigation, evaluations on the reliability, validity and reactivity of the measuring scale, according to the principles for measuring scale design and under the guidance of CM theories. Results: The measuring scale was composed of two integrative parts: the self-filling section and the interview section. As far as the reliability was concerned, the total Cronbach a coefficient of the measuring scale was 0.866, the total test-retest reliability coefficient was 0.726 and the split-half reliability coefficient was 0.851. As far as the validity was concerned, the scores for the subjects of fire-heat syndrome in oral cavity and healthy people in their oral cavity in the items of symptoms were statistically different (P〈0.01); three common divisors were extracted according to the theoretical dimensions, the accumulated contribution rate was 63.468%. As far as the reactivity was concerned, the difference between the symptom scores before and after the test in which 31 subjects used the Chinese herb toothpaste was statistically significant (P〈O.01). Conclusions: This measuring scale has relatively good reliability, validity and reactivity, and it can be used in an objective quantitative evaluation on patients suffering from fire-heat syndrome in oral cavity, and thus lay the foundations for the evaluations on the therapeutic effects of Chinese herb toothpaste on fire-heat syndrome in oral cavity.展开更多
This paper is devoted to the investigation of stability for singular and time-delay measure differential large scale systems with impulsive solution.With the help of Drazin inverse,the variation of parameters formula ...This paper is devoted to the investigation of stability for singular and time-delay measure differential large scale systems with impulsive solution.With the help of Drazin inverse,the variation of parameters formula of large scale singular systems containing measures and delays is obtained.Employing inequality methods and comparison theory,the stability properties of large scale systems are studied.展开更多
This paper is devoted to the investigation of Lyapunov's second method for the stability of measure differential large scale systems containing impulses. The vector comparison principle of the stability of measur...This paper is devoted to the investigation of Lyapunov's second method for the stability of measure differential large scale systems containing impulses. The vector comparison principle of the stability of measure differential large scale systems is first established. An application of the vector comparison theorem is given to demonstrate the effectiveness of our result.展开更多
A birth-death process is considered as an epidemic model with recovery and transmittance from outside.The fraction of infected individuals is for huge population sizes approximated by a solution of an ordinary differe...A birth-death process is considered as an epidemic model with recovery and transmittance from outside.The fraction of infected individuals is for huge population sizes approximated by a solution of an ordinary differential equation taking values in[0,1].For intermediate size or semilarge populations,the fraction of infected individuals is approximated by a diffusion formulated as a stochastic differential equation.That diffusion approximation however needs to be killed at the boundary{0}U{1}.An alternative stochastic differential equation model is investigated which instead allows a more natural reflection at the boundary.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant No.15572072)the National Key Basic Research and Development Program(Grant Nos.2014CB046803 and 2016ZX05028-002-005)
文摘By focusing on the vulnerability of the structure of marine equipments, together with considering the randomness of meta-ocean load in statistics, a kind of analytical method of fatigue characteristics of marine structure based on full- scale and actual measurement of prototype is proposed. On the basis of short-term field measurement results of structural response, research is carried out on the fatigue analysis of hinge joints at the upper part of the Soft Yoke single point Mooring System (SYMS) by simultaneously monitoring the environmental load and considering the design criteria of offshore structure. Through analysis of finite element modeling, the time-histories of typical stress response are obtained, and then the assessment of fatigue damage at key hinge joints is conducted. The simulation results indicate that the proposed method can accurately analyze the fatigue damage of offshore engineering structure caused by the effect of wave load. The present analytical method of fatigue characteristics can be extended on other offshore engineering structures subjected to meta-ocean load.
基金supported by the National Natural Science Foundation of China(Grant Nos.61871386,61971427,62035014,and 61921001)the Natural Science Fund for Distinguished Young Scholars of Hunan Province,China(Grant No.2019JJ20022)。
文摘In the terahertz band,the dispersive characteristic of dielectric material is one of the major problems in the scaled radar cross section(RCS)measurement,which is inconsistent with the electrodynamics similitude deducted according to the Maxwell’s equations.Based on the high-frequency estimation method of physical optics(PO),a scaled RCS measurement method for lossy objects is proposed through dynamically matching the reflection coefficients according to the distribution of the object facets.Simulations of the model of SLICY are conducted,and the inversed RCS of the lossy prototype is obtained using the proposed method.Comparing the inversed RCS with the calculated results,the validity of the proposed method is demonstrated.The proposed method provides an effective solution to the scaled RCS measurement for lossy objects in the THz band.
文摘Objectives: This study was designed to test and validate the new LPD scale in a home care setting. The specific objectives are to validate the LPD scale for subjects cared for at home;and to compare LPD to the Braden scale for internal validity. Method: This multicenter, cross-sectional study was conducted in the domestic environment of subjects cared for Home Care services from North to South of Italy. Data collection lasted 8 months, between June 2018 and September 2020, and consisted of the simultaneous compilation of the new LPD, and the Braden scale. Home Care Expert nurses could interface with the recruited subjects and/or caregivers. The parameters considered to validate the new scale were sensitivity (Se), specificity (Sp), positive predictive values (PPV), odds ratio (OR), and the area under the receiver operating characteristic (ROC) curve. Results: Of the 679 recruited subjects, 63.2% were women, and more than 50% did not have a pressure ulcer. 48.2% of the sample aged over 85 years old;69% was affected by multiple disease, and 76.6% took a lot of drugs. 91.6% of the subjects were affected by a partial or total functional dependency. Around 50% of subjects presented double incontinence, and 43% were conscious and collaborated. 85.4% of subjects lived in a healthy environment. The predictive validity parameters showed: Se 77.25%, Sp 84.04%, PPV 91.37%, and the area under the curve (AUC) 0.88% with a confidence interval (CI) 95%. These values mean a moderately accuracy of the test. Conclusions: The new LPD scale has demonstrated a good capacity for identifying the subjects at risk of pressure ulcer and had a better discriminatory power rather than Braden scale.
文摘There are several shape measures for quantitative variables, some of which can also be applied to ordinal variables. In quantitative variables, symmetry, peakedness, and kurtosis are essential properties to evaluate the deviation from assumptions, particularly normality. They aid in selecting the most appropriate method for estimating parameters and testing hypotheses. Initially, these properties serve a descriptive role in qualitative variables. Once defined, they can be considered to check for non-compliance with assumptions and to propose modifications for testing procedures. The objective of this article is to present three measures of the shape of the distribution of a qualitative variable. The concepts of qualitative asymmetry and peakedness are defined. The measurement of the first concept involves calculating the average frequency difference between qualitative categories matched by frequency homogeneity or proximity. For the second concept, the peak-to-shoulder difference and the qualitative percentile kurtosis are taken into consideration. This last measurement is a less effective option than the peak-to-shoulder difference to measure peakedness. A simulated example of the application of these three measures is given and the paper closes with some conclusions and suggestions.
文摘There are several shape measures for quantitative variables, some of which can also be applied to ordinal variables. In quantitative variables, symmetry, peakedness, and kurtosis are essential properties to evaluate the deviation from assumptions, particularly normality. They aid in selecting the most appropriate method for estimating parameters and testing hypotheses. Initially, these properties serve a descriptive role in qualitative variables. Once defined, they can be considered to check for non-compliance with assumptions and to propose modifications for testing procedures. The objective of this article is to present three measures of the shape of the distribution of a qualitative variable. The concepts of qualitative asymmetry and peakedness are defined. The measurement of the first concept involves calculating the average frequency difference between qualitative categories matched by frequency homogeneity or proximity. For the second concept, the peak-to-shoulder difference and the qualitative percentile kurtosis are taken into consideration. This last measurement is a less effective option than the peak-to-shoulder difference to measure peakedness. A simulated example of the application of these three measures is given and the paper closes with some conclusions and suggestions.
基金supported by National Natural Science Foundation of China under Grant No.70832004Ministry of Education of the People's Republic of China under Grant No. 09YJC630074East China University of Science and Technology under Grant No.WN0922015
文摘This study investigates how traditional Chinese values influence Chinese consumer behavior directly and indirectly through the impact on people's lifestyles and perceived values.The empirical research is conducted in the context of the mobile phone market in Shanghai.The study establishes measurement scales of Confucian value,lifestyle,and customer perceived value for Chinese market.Relationships of multiple factors are tested in the structural equation model and their impacts on consumer behavior are elaborated.Findings indicate that Confucian values not only have a direct impact on Chinese consumer behavior but also indirectly influence this behavior through impacting people's lifestyles and perceived values.
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education,Science and Technology(2012-013997)
文摘The corticoreticular tract (CRT) is known to be involved in walking and postural control. Using diffusion tensor tractography (DTT), we investigated the relationship between the CRT and gait dysfunction, includ- ing trunk instability, in pediatric patients. Thirty patients with delayed development and 15 age-matched, typically-developed (TD) children were recruited. Fifteen patients with gait dysfunction (bilateral trunk instability) were included in the group A, and the other 15 patients with gait dysfunction (unilateral trunk instability) were included in the group B. The Growth Motor Function Classification System, Functional Ambulation Category scale, and Functional Ambulation Category scale were used for measurement of functional state. Fractional anisotropy, apparent diffusion coefficient, fiber number, and tract integrity of the CRT and corticospinal tract were measured. Diffusion parameters or integrity of corticospinal tract were not significantly different in the three study groups. However, CRT results revealed that both CRTs were disrupted in the group A, whereas CRT disruption in the hemispheres contralateral to clinical mani- festations was observed in the group B. Fractional anisotropy values and fiber numbers in both CRTs were decreased in the group A than in the group TD. The extents of decreases of fractional anisotropy values and fiber numbers on the ipsilateral side relative to those on the contralateral side were greater in the group B than in the group TD. Functional evaluation data and clinical manifestations were found to show strong correlations with CRT status, rather than with corticospinal tract status. These findings suggest that CRT status appears to be clinically important for gait function and trunk stability in pediatric patients and DTT can help assess CRT status in pediatric patients with gait dysfunction.
文摘High performance Dynamic Light Scattering (DLS) has been used to determine the hydrodynamic di-ameters of CdSe nanocrystals as well as CdSe cluster molecules in a size range of 1 to 10 nm (Eichh鰂er et al., 2001). The method enables the determination of their particle size, including their ligand shells, in solution. The results are consistent with the blue shift of the absorption bands, as well as Transmission Electron Microscope (TEM) experiments. The sizes of the cluster molecules were estimated from space filling models constructed from the results of a single crystal X-ray structure determination. DLS gave comparable results for the size of both types of compound, indicating that it is potentially an important additional measurement technique to TEM, which uses harsh measurement conditions, and to powder X-ray diffraction, which is difficult to interpret below 5 nm.
文摘Diving is a recreational activity of growing significance in many countries.In the recreational SCUBA diving industry,a liveaboard service offers tourists to stay on board for several nights and that allows time to travel to more distant dive sites.SCUBA diving belongs to an adventure tourism,while cruise is much more leisure tourism activity.However,they share a similar travel mode,so it is very interesting to find the reason behind.Do cruise tourists be the potential diving tourists?The paper adopted the cruising motivation scale for diving tourists to develop a scale for SCUBA divers’motivations of liveaboard.Convenience sampling was used to select participants for the study.After exploratory factor analysis(EFA),the results showed that there were six dimension of SCUBA divers’liveaboard motivation,and the added dimension of divers’preference was valid.Finally,a measurement scale of SCUBA divers’liveaboard motivation was proposed in this study,and the discussion and implication were also presented in the paper.
文摘Many impulsive phenomena from physics, control theory, and economics urge us toinvestigate measure large scale systems. In this paper, the variation of parameters formulaof the large scale systems containing measures is established. By means of inequality methods and comparison theory, the stability, uniform stability, asymptotic stability, uniformasymptotic stability, and exponential stability properties of linear measure large scale systems are studied.
基金Supported by China National Funds for Distinguished Young Scientists(No.30825046)Proctor and Gamble Technology(Beijing)Ltd.Co.Program for Innovative Research Team in Beijing University of Chinese Medicine(2011CXTD-07)
文摘Objective: To formulate the standard measuring tool for the evaluations on fire-heat syndrome in oral cavity by means of Chinese medicine (CM). Methods: The measuring scale for fire-heat syndrome in the oral cavity by means of CM was investigated by symptom collection, item pool formulation, item selection, pre-investigation, evaluations on the reliability, validity and reactivity of the measuring scale, according to the principles for measuring scale design and under the guidance of CM theories. Results: The measuring scale was composed of two integrative parts: the self-filling section and the interview section. As far as the reliability was concerned, the total Cronbach a coefficient of the measuring scale was 0.866, the total test-retest reliability coefficient was 0.726 and the split-half reliability coefficient was 0.851. As far as the validity was concerned, the scores for the subjects of fire-heat syndrome in oral cavity and healthy people in their oral cavity in the items of symptoms were statistically different (P〈0.01); three common divisors were extracted according to the theoretical dimensions, the accumulated contribution rate was 63.468%. As far as the reactivity was concerned, the difference between the symptom scores before and after the test in which 31 subjects used the Chinese herb toothpaste was statistically significant (P〈O.01). Conclusions: This measuring scale has relatively good reliability, validity and reactivity, and it can be used in an objective quantitative evaluation on patients suffering from fire-heat syndrome in oral cavity, and thus lay the foundations for the evaluations on the therapeutic effects of Chinese herb toothpaste on fire-heat syndrome in oral cavity.
文摘This paper is devoted to the investigation of stability for singular and time-delay measure differential large scale systems with impulsive solution.With the help of Drazin inverse,the variation of parameters formula of large scale singular systems containing measures and delays is obtained.Employing inequality methods and comparison theory,the stability properties of large scale systems are studied.
文摘This paper is devoted to the investigation of Lyapunov's second method for the stability of measure differential large scale systems containing impulses. The vector comparison principle of the stability of measure differential large scale systems is first established. An application of the vector comparison theorem is given to demonstrate the effectiveness of our result.
文摘A birth-death process is considered as an epidemic model with recovery and transmittance from outside.The fraction of infected individuals is for huge population sizes approximated by a solution of an ordinary differential equation taking values in[0,1].For intermediate size or semilarge populations,the fraction of infected individuals is approximated by a diffusion formulated as a stochastic differential equation.That diffusion approximation however needs to be killed at the boundary{0}U{1}.An alternative stochastic differential equation model is investigated which instead allows a more natural reflection at the boundary.