AN INVESTIGATION OF RETINEX ALGORITHMS FOR IMAGE ENHANCEMENT

This letter introduces color constancy and Retinex theory for image enhancement.It clas- sifies Retinex algorithms into four categories and provides their principles and implementations in general.The experimental results of Frankle-McCann,MSR (Multi-Scale Retinex) and PNSD (Pro- jected Normalized Steepest Descent) Retinex algorithms are presented and compared.Moreover, variance and average gradient are proposed to evaluate the performance of the different algorithms.

Definition, theory, methods, and applications of the safe and efficient simultaneous extraction of coal and gas

Simultaneous extraction of the coal and gas is an effective method of eliminating coal mine gas disasters while safely exploiting the coal and achieving efficient gas drainage in China, which is widely accepted by the main coal-producing countries around the world. However, the concrete definition of simultaneous extraction is vague and there is little accurate theoretical support for the simultaneous extraction of coal and gas, which makes it difficult to determine an efficient gas drainage method appropriate to the features of coal seams. Based on theoretical analysis, laboratory tests and field observations, a specific definition of simultaneous extraction of coal and gas is proposed after analyzing the characteristics of coal seam occurrences in China, and we developed the mechanism of mining-enhanced permeability and established the corresponding theoretical model. This comprises a process of fracture network formation, in which the original fractures are opened and new fractures are produced by unloading damage. According to the theoretical model, the engineering approaches and their quantitative parameters of ＇unloading by borehole drilling＇ for single coal seams and ＇unloading by protective seam mining＇ for groups of coal seams are proposed, and the construction principles for coal exploitation and gas-drainage systems for different conditions are given. These methods were applied successfully in the Tunlan Coal Mine in Shanxi Province and the Panyi Coal Mine in Anhui Province and could assure safe and efficient simultaneous extraction of coal and gas in these outburst coal mines.

Decomposition patterns of leaf litter of seven common canopy species in a subtropical forest： dynamics of mineral nutrients

Dynamical patterns of mineral elements during decomposition processes were investigated for seven common canopy species in a subtropical evergreen broad-leaved forest by means of litterbag technique over 2 years. The species studied are representative for the vegetation in the study area and differed significantly in chemical qualities of their litter. No significant relationships were found between decomposition rate （percentage dry mass remaining and decomposition constant k） and initial element cuncentrations.However, there were significant correlations betweeu the percentage of dry mass remaining and the mineral element concentrations in the remaining litter for most cases. The rank of the element mobility in decomposition process was as follows： Na = K 〉 Mg ≥ Ca 〉 N ≥ Mn ≥ Zn ≥ P 〉 Cu 〉〉 Al 〉〉 Fe. Concentrations of K and Na decreased in all species as decomposition proceeded. Calcium and Mg also decreased in concentrntion but with a temporal increase in the initial phase of decomposition, while the concentrations of other elements （Zn, Cu, AL and Fei increased for all species with exception of Mn which revealed a different pattern in different species. In most species, microelements （Cu, Al, and Fe） significantly increased in absolute amounts at the end of the litterbag incubation, which could be ascribed to a lange extent to the mechanism of abiotic fixation to humic substances rather than biological immobilization.

Treatment of Unresectable Advanced Gastric Cancer Using lodine-125 Brachytherapy

OBJECTIVE The purpose of the study was to examine the efficacy of treating patients with advanced gastric cancer using iodine-125 （^125Ⅰ） brachytherapy. METHODS Ten patients with unresectable advanced gastric cancer were selected based on their pattern of CT scans. We utilized a brachytherapy planning system to determine the distribution of the ^125Ⅰ seeds, their activity and quantity. The matched peripheral dose （MPD） was 110-135 Gy.^125Ⅰ seeds were implanted in a single plane or biplane by an intraoperative small incision or percutaneous puncture. The postoperative hemogram, CT, KPS, pain-relieving period and survival period were recorded. RESULTS One patient developed a complete response （CR）, 4 patients a partial response （PR）, 3 patients showed no change （NC） and 2 patients developed progressive disease （PD）. The overall response rate （CR＋PR） was 50% （5/10）. The pain-relieving rate was 89% （8/9）. The patients＇ appetite and KPS were improved. The longest survival period was 10 months and median life span was 4 months. There were 8 patients whose seeds fell off resulting in an expulsion rate of 3.8% （26/692）. The patients showed 0-1 degree acute radio-therapeutic side-effects without other symptoms such as abdominal pain, vomitus cruentes or intestinal obstruction etc.CONCLUSION Applying ^125Ⅰ implantation to treat advanced gastric cancer with a reasonable seed distribution can significantly improve clinical symptoms and their quality of life. The radioactive damage is mild. This method can be used as an important supplementary treatment for unresectable advanced gastric cancer.

Longhole waterjet rotary cutting for in-seam cross panel methane drainage

In order to improve the efficiency of gas drainage before and during longwall extraction,a waterjet rotary cutting system has been developed for in-seam cross panel methane drainage.The purpose of the water rotary cutting system developed was to create artificial fractures along the gas drainage boreholes.During the design of the system,it was perceived that the nozzle geometry is one of the key factors,affecting cutting capacity.Therefore,we studied the structural and geometric parameters of the nozzle and optimized its performance during laboratory tests and numerical simulation.Underground trials conducted in a coal mine,indicate that production of gas drainage before and after cutting significantly increased by up to three times.The advantages of waterjet assisted gas drainage method has been identified as:1) increasing gas drainage efficiency,2) a possible development of a gas drainage fractured network within coal seams associated with panel extraction,and 3) reducing the risk of exceeding gas limits during longwalling.

Space range estimate for battery-powered vertical take-off and landing aircraft

A novel method for estimating the space range of battery-powered vertical take-off and landing(VTOL) aircraft is presented. The method is based on flight parameter optimization and numerical iteration. Subsystem models including required thrust, required power and battery discharge models are presented. The problem to be optimized is formulated, and then case study simulation is conducted using the established method for quantitative analysis. Simulation results show that the space range of battery-powered VTOL aircraft in a vertical plane is an oblate curve, which appears horizontally long but vertically short, and the peak point is not located on the vertical climb path. The method and results are confirmed by parameter analysis and validations.

Study on the Concept of Per Capita Cumulative Emissions and Allocation Options

Global long-term emission reduction targets need well defined options for equitable allocation of greenhouse gas emissions. Scholars from developing countries put forward the concept of equitable per capita cumulative emission rights. There are four possible operational definitions resulting from this concept. These potential options for allocation of emission rights are expressed with mathematical equations. Through simple simulation, this paper reveals the advantages, disadvantages and characteristics of each option.

Application and development of numerical simulation for under- ground horizontal directional drilling

In coalmines of China, horizontal directional drilling （HDD） is an increasingly popular method for underground in-seam gas drainage. Numerical simulation, especially finite element analysis, is often used as an effective method to improve HDD operation. These improvements focus on rock-breaking efficiency, directional precision, stability of the borehole wall, and reliability of the drill equipment. On the basis of underground drilling characteristics, typical numerical simulation exam- ples in drilling techniques and equipment are summarized and analyzed. In the end, the future development trends of numerical simulation in underground in-seam drilling are proposed.

The control of coal mine gas and coordinated exploitation of coal bed methane in China

Based on the characteristics of the coalfield geology and the distribution of coalbed methane (CBM) in China,the geological conditions for exploiting the CBM and drainingthe coal mine gas were analyzed,as well as the characteristics of CBM production.Bycomparing the current situation of CBM exploitation in China with that in the United States,the current technology and characteristics of the CBM exploitation in China were summarizedand the major technical problems of coal mine gas control and CBM exploitationanalyzed.It was emphasized that the CBM exploitation in China should adopt the coalmine gas drainage method coordinated with coal mine exploitation as the main model.Itwas proposed that coal mine gas control should be coordinated with coal mine gas exploitation.The technical countermeasure should be integrating the exploitation of coal andCBM and draining gas before coal mining.

DOA ESTIMATION FOR WIDEBAND SOURCES BASED ON UCA

A new Direction Of Arrival （DOA） estimation algorithm for wideband sources based on Uniform Circular Array （UCA） is presented via analyzing widcband performance of the general ESPRIT. The algorithm effectively improves the wideband performance of ESPRIT based on the interpolation principium and UCA-ESPRIT. The simulated results by computer demonstrate its efficiency.

A Low-Power Super-Performance Four-Way Set-Associative CMOS Cache Memory

A 1.8-V 64-kb four-way set-associative CMOS cache memory implemented by 0.18μm/1.8V 1P6M logic CMOS technology for a super performance 32-b RISC microprocessor is presented.For comparison,a conventional parallel access cache with the same storage and organization is also designed and simulated using the same technology.Simulation results indicate that by using sequential access,power reduction of 26% on a cache hit and 35% on a cache miss is achieved.High-speed approaches including modified current-mode sense amplifier and split dynamic tag comparators are adopted to achieve fast data access.Simulation results indicate that a typical clock to data access of 2.7ns is achieved...

Effect of aeration on fast gas pressure tests

Given the problem of the long time required for testing gas pressure, we propose a fast-test method in which we used a technique of fast borehole sealing and air replenishing. Based on the characteristics of gas emission from boreholes to be tested, we built a theoretical model for calculating parameters during the process of increasing natural pressure and aeration. Using this model, we investigated the effect of different aeration conditions on velocity of pressure tests. The result shows that: 1) aerating air into boreholes can speed up gas pressure tests and 2) the more similar the pressure of the aerated air to the original gas pressure, the smaller the gas volume absorbed by coal and the shorter the time needed in pressure test. A case study in the Lu’an mining area shows that the time needed for gas pressure test is only 4 h using our method of aeration and 29 h under conditions of increasing natural pressure, saving time by 86.2%. This case study also indicates that, by using the aeration method, only one hour is needed for gas pressure to reach a stable state, which breaks the record of the shortest time needed for gas pressure tests in China.

New methods for the management of esophageal varices

Bleeding from esophageal varices (EVs) is a catastrophic complication of chronic liver disease. Many years ago, surgical procedures such as esophageal transection or distal splenorenal shunting were the only treatments for EVs. In the 1970s, interventional radiology procedures such as transportal obliteration, left gastric artery embolization, and partial splenic artery embolization were introduced, improving the survival of patients with bleeding EVs. In the 1980s, endoscopic treatment, endoscopic injection sclerotherapy (EIS), and endoscopic variceal ligation (EVL), further contributed to improved survival. We combined IVR with endoscopic treatment or EIS with EVL. Most patients with EVs treated endoscopically required follow- up treatment for recurrent varices. Proper management of recurrent EVs can significantly improve patients’ quality of life. Recently, we have performed EVL at 2-mo (bimonthly) intervals for the management of EVs. Longer intervals between treatment sessions resulted in a higher rate of total eradication and lower rates of recurrence and additional treatment.

Relation Between Dimension and Angular Momentum for Radially Symmetric Potential in N-Dimensional Space

It is proved that when solving SchrSdinger equations for radially symmetric potentials the effect of higher dimensions on the radial wave function is equivalent to the effect of higher angular momenta in lower-dimensional cases. This result is applied to giving solutions for several radially symmetric potentials in N dimensions.

Effects of various sintering methods on microstructure and mechanical properties of CP-Ti powder consolidations

Effects of various sintering methods such as spark plasma sintering(SPS), hot pressing(HP) and electric resistance sintering(ERS) on the microstructure and mechanical properties of commercial pure titanium(CP-Ti) powder consolidations with particle size of <147 μm, <74 μm and <43 μm were studied. The smaller particle powders are densified to proceed at a higher rate. Dense titanium with relative density up to 99% is found to take place at 850 °C under 30 MPa of SPS and HP condition. However, in case of ERS, CP-Ti powders were densified almost at 950 °C under 30 MPa. The microstructure of sintered titanium is composed of equiaxed grains at 850-950 °C. The yield strength of sintered body composed of <43 μm powder is 858 MPa by using SPS at 850 °C under 30 MPa. When there is a higher content of small particle, the higher yield strength value is obtained both by using SPS and HP. However, when ERS is introduced, the highest yield strength is 441 MPa at 950 °C under 30 MPa, which shows much lower values than those by SPS and HP methods. ERS method takes much less sintering time compared with SPS and HP. Nevertheless, higher sintering temperature results in lower strength and elongation because of brittle fracture.

A general solution and approximation for the diffusion of gas in a spherical coal sample

The square root relationship of gas release in the early stage of desorption is widely used to provide a simple and fast estimation of the lost gas in coal mines. However, questions arise as to how the relationship was theoretically derived, what are the assumptions and applicable conditions and how large the error will be. In this paper, the analytical solutions of gas concentration and fractional gas loss for the diffusion of gas in a spherical coal sample were given with detailed mathematical derivations based on the diffusion equation. The analytical solutions were approximated in case of small values of time and the error analyses associated with the approximation were also undertaken. The results indicate that the square root relationship of gas release is the first term of the approximation, and care must be taken in using the square root relationship as a significant error might be introduced with increase in the lost time and decrease in effective diameter of a spherical coal sample.

Technology of gas drainage and utilization in Huaibei mining area

With the characteristics of coal seam geology and gas occurrence,a'ground-underground' integrated gas drainage method was formed,which can relieve gaspressure and increase permeability by mining the protection seams in conditional regions.After coal seam gas drainage,high gas outburst seam was converted to low gas safetyseam.In the coal face mining process,safety and high efficient coal mining were realizedby the measure of gas-suction over mining.In addition to the drainage gas for civil gasand gas power generation,the Huaibei Mining Group has actively carried out research onthe utilization technology of methane drainage by ventilation.On the one hand,it can saveprecious energy;on the other hand,it can protect the environment for people's survival.In2007,the amount of coal mine gas drainage was 120 hm3;the rate of coal mine gasdrainage was 44%.Compared with the year 2002,the amount of coal mine gas drainageincreased by two times.Meanwhile,the utilization rate of gas increased rapidly.

The Semi-implicit Euler Method for Stochastic Pantograph Equations with Jumps

In this paper,we present the semi-implicit Euler（SIE）numerical solution for stochastic pantograph equations with jumps and prove that the SIE approximation solution converges to the exact solution in the mean-square sense under the Local Lipschitz condition.

Gefitinib combined with γ-ray stereotactic body radiation therapy has better efficacy than gefitinib alone for senile lung adenocarcinoma patients with EGFR mutations as first-line regimen

Objective： The senile lung adenocarcinoma patients harboring an activating epidermal growth factor receptor （EGFR） mutation shows good and rapid response to EGFR tyrosine kinase inhibitors （TKIs）. Whether gefitinib combined with y-ray stereotactic body radiation therapy has better efficacy than gefitinib alone for senile lung adenocarcinoma patients with EGFR mutations as first-line regimen is still under investigation. Methods： The 42 senile lung adenocarcinoma patients with EGFR mutations were divided into 2 groups according to the therapy method. Group A was the 22 patients treated with gefitinib combined with y-ray stereotactic body radiation therapy （SBRT）. Group B was the 20 patients treated with gefitinib alone. All of the patients received gefitinib of 250 mg/d from the first day until disease progression or other reasons. The patients of Group A were treated with y-ray stereotactic body radiation therapy from the second day. Radiation fields included the primary lesions and the integration of lymph nodes. Dose curve of this group was 50%-80%. Encircled dose was 4.0-6.5 Gy per fraction and the range of total dose was 40-52 Gy. We treated the patients 8-12 times and treated five times every week. Results： All the patients were examined by enhanced double helix CT at the second month. The tumor response rate （RR） of group A was 81.8% （18/22）. Disease control rate （DCR） was 90.9% （20/22）. The median overall survival （OS） was 24.2 months （range 8-58 months ） and the progression-free survival （PFS） was 18.6 months. The overall 1-year survival rate was 72.3% （16/22） and 2-year survival rate was 54.5% （12/22）. The main side effects included skin rash and diarrhea. The RR of group B was 50.0 % （10/20）. DCR was 75.0% （15/20）. OS was 17.4 months （range 6-32 months ） and PFS was 12.1 months. The overall 1-year survival rate was 60.0% （12/20） and 2-year survival rate was 40.0% （8/20）. The main side effects included skin rash and diarrhea. The group A who were treated with gefitinib combined with y-ray stereotactic body radiation therapy had a higher short term therapeutic effects （RR） and long term therapeutic effects （OS） than group B who were treated with gefitinib alone respectively （81.8% vs 50.0%, P = 0.029 〈 0.05, x2 = 4.773 and 24.2 vs 17.4, P = 0.024 〈 0.05, X2 = 5.098）. Conclu. sion： Gefitinib combined with y-ray stereotactic body radiation therapy has better efficacy than gefitinib alone for senile lung adenocarcinoma patients with EGFR mutations as first-line regimen. The side affects are acceptable.

Kinetic Behaviour of the Aggregation—Annihilation Process of Two—Species—Group System

The kinetic behavior of an aggregation-annihilation system with two species groups is studied in this paper.We propose that an aggregation reaction occurs only between the same species and an irreversible joint annihilation reaction occurs only between the two species belonging to distinct groups. Based on the mean-field theory, we investigate the rate equations of the process with constant reaction rates and obtain the asymptotic descriptions of the cluster-mass distributions for the symmetrical cases. We find that the cluster-mass distribution of each species obeys a standard scaling description in certain cases. Meanwhile, breakdown of the standard scaling description is also found for the distribution in some special cases and the cluster-mass distribution comes in a peculiar scaling regime. The evolutionbehaviour of the system depends crucially on the reaction rates and the ratio of initial concentrations between the two groups. Moreover, the species numbers of the two groups also play important roles in the properties of the cluster distributions.