为了及时跟进国际研究前沿,以充实和完善我国听障儿童康复干预体系,本研究选择国际权威学术期刊《Clinical Linguistics & Phonetics》,选取其中59篇聚焦于听障儿童语言习得与康复干预的核心文献,以期通过对期刊总计1194篇文献进行...为了及时跟进国际研究前沿,以充实和完善我国听障儿童康复干预体系,本研究选择国际权威学术期刊《Clinical Linguistics & Phonetics》,选取其中59篇聚焦于听障儿童语言习得与康复干预的核心文献,以期通过对期刊总计1194篇文献进行深入可视化处理后,探究听障儿童相关研究在二十年期间内的主要聚焦点。根据研究领域的变迁,将听障儿童语言习得与康复干预的研究分为三个阶段:阶段一(2002~2008年),该阶段的研究主要以语音学为核心;阶段二(2009~2015年),语音学研究依旧占据主导,但非语音学研究开始逐步增多,显示听障儿童语言康复研究的初步拓展;阶段三(2016~2022年),非语音学相关研究的数量和影响力显著超越语音学研究,标志着听障儿童语言康复研究进入了多元化发展阶段。In order to follow up the international research frontier in time, so as to enrich and improve the rehabilitation intervention system of hearing-impaired children in China, this study selected the international authoritative academic journal Clinical Linguistics & Phonetics, and selected 59 core literatures focusing on language acquisition and rehabilitation intervention of hearing-impaired children, in order to explore the main focus points of related research on hearing-impaired children in 20 years after in-depth visualization of a total of 1194 literatures in the journal. According to the changes of research fields, the research on language acquisition and rehabilitation intervention of hearing-impaired children is divided into three stages: stage 1 (2002~2008), which mainly focuses on phonetics;In the second stage (2009~2015), phonetic research still dominates, but non-phonetic research begins to gradually increase, showing the initial expansion of language rehabilitation research for hearing-impaired children;In the third stage (2016~2022), the number and influence of non-phonetics-related research significantly surpassed that of phonetics research, marking that language rehabilitation research for hearing-impaired children has entered a diversified development stage.展开更多
Considering Pythagorician divisors theory which leads to a new parameterization, for Pythagorician triplets ( a,b,c )∈ ℕ 3∗ , we give a new proof of the well-known problem of these particular squareless numbers n∈ ℕ...Considering Pythagorician divisors theory which leads to a new parameterization, for Pythagorician triplets ( a,b,c )∈ ℕ 3∗ , we give a new proof of the well-known problem of these particular squareless numbers n∈ ℕ ∗ , called congruent numbers, characterized by the fact that there exists a right-angled triangle with rational sides: ( A α ) 2 + ( B β ) 2 = ( C γ ) 2 , such that its area Δ= 1 2 A α B β =n;or in an equivalent way, to that of the existence of numbers U 2 , V 2 , W 2 ∈ ℚ 2∗ that are in an arithmetic progression of reason n;Problem equivalent to the existence of: ( a,b,c )∈ ℕ 3∗ prime in pairs, and f∈ ℕ ∗ , such that: ( a−b 2f ) 2 , ( c 2f ) 2 , ( a+b 2f ) 2 are in an arithmetic progression of reason n;And this problem is also equivalent to that of the existence of a non-trivial primitive integer right-angled triangle: a 2 + b 2 = c 2 , such that its area Δ= 1 2 ab=n f 2 , where f∈ ℕ ∗ , and this last equation can be written as follows, when using Pythagorician divisors: (1) Δ= 1 2 ab= 2 S−1 d e ¯ ( d+ 2 S−1 e ¯ )( d+ 2 S e ¯ )=n f 2;Where ( d, e ¯ )∈ ( 2ℕ+1 ) 2 such that gcd( d, e ¯ )=1 and S∈ ℕ ∗ , where 2 S−1 , d, e ¯ , d+ 2 S−1 e ¯ , d+ 2 S e ¯ , are pairwise prime quantities (these parameters are coming from Pythagorician divisors). When n=1 , it is the case of the famous impossible problem of the integer right-angled triangle area to be a square, solved by Fermat at his time, by his famous method of infinite descent. We propose in this article a new direct proof for the numbers n=1 (resp. n=2 ) to be non-congruent numbers, based on an particular induction method of resolution of Equation (1) (note that this method is efficient too for general case of prime numbers n=p≡a ( ( mod8 ) , gcd( a,8 )=1 ). To prove it, we use a classical proof by induction on k , that shows the non-solvability property of any of the following systems ( t=0 , corresponding to case n=1 (resp. t=1 , corresponding to case n=2 )): ( Ξ t,k ){ X 2 + 2 t ( 2 k Y ) 2 = Z 2 X 2 + 2 t+1 ( 2 k Y ) 2 = T 2 , where k∈ℕ;and solutions ( X,Y,Z,T )=( D k , E k , f k , f ′ k )∈ ( 2ℕ+1 ) 4 , are given in pairwise prime numbers.2020-Mathematics Subject Classification 11A05-11A07-11A41-11A51-11D09-11D25-11D41-11D72-11D79-11E25 .展开更多
Ports play a fundamental role in a sustainable integration of Africa in International trade. Both importers and exporters, shipping companies and government, however face high cost for sea transport and substantial in...Ports play a fundamental role in a sustainable integration of Africa in International trade. Both importers and exporters, shipping companies and government, however face high cost for sea transport and substantial inefficiency in port operations. This has resulted in congestion, higher dwell time, higher costs which affect the competitive ability in sub regional and global economy. This study investigates the main factors explaining poor container handling operations and limited competitive ability in Cameroonian Ports and aggregating this to the competitive position of Cameroonian ports in the West and Central African sub-regions (WCA). Using Analytic Hierarchy Process (A.H.P), the paper seeks to provide a basic understanding of container transportation and port’s terminal operations problems (constraints & ineffectiveness) in Cameroon.展开更多
文摘为了及时跟进国际研究前沿,以充实和完善我国听障儿童康复干预体系,本研究选择国际权威学术期刊《Clinical Linguistics & Phonetics》,选取其中59篇聚焦于听障儿童语言习得与康复干预的核心文献,以期通过对期刊总计1194篇文献进行深入可视化处理后,探究听障儿童相关研究在二十年期间内的主要聚焦点。根据研究领域的变迁,将听障儿童语言习得与康复干预的研究分为三个阶段:阶段一(2002~2008年),该阶段的研究主要以语音学为核心;阶段二(2009~2015年),语音学研究依旧占据主导,但非语音学研究开始逐步增多,显示听障儿童语言康复研究的初步拓展;阶段三(2016~2022年),非语音学相关研究的数量和影响力显著超越语音学研究,标志着听障儿童语言康复研究进入了多元化发展阶段。In order to follow up the international research frontier in time, so as to enrich and improve the rehabilitation intervention system of hearing-impaired children in China, this study selected the international authoritative academic journal Clinical Linguistics & Phonetics, and selected 59 core literatures focusing on language acquisition and rehabilitation intervention of hearing-impaired children, in order to explore the main focus points of related research on hearing-impaired children in 20 years after in-depth visualization of a total of 1194 literatures in the journal. According to the changes of research fields, the research on language acquisition and rehabilitation intervention of hearing-impaired children is divided into three stages: stage 1 (2002~2008), which mainly focuses on phonetics;In the second stage (2009~2015), phonetic research still dominates, but non-phonetic research begins to gradually increase, showing the initial expansion of language rehabilitation research for hearing-impaired children;In the third stage (2016~2022), the number and influence of non-phonetics-related research significantly surpassed that of phonetics research, marking that language rehabilitation research for hearing-impaired children has entered a diversified development stage.
文摘Considering Pythagorician divisors theory which leads to a new parameterization, for Pythagorician triplets ( a,b,c )∈ ℕ 3∗ , we give a new proof of the well-known problem of these particular squareless numbers n∈ ℕ ∗ , called congruent numbers, characterized by the fact that there exists a right-angled triangle with rational sides: ( A α ) 2 + ( B β ) 2 = ( C γ ) 2 , such that its area Δ= 1 2 A α B β =n;or in an equivalent way, to that of the existence of numbers U 2 , V 2 , W 2 ∈ ℚ 2∗ that are in an arithmetic progression of reason n;Problem equivalent to the existence of: ( a,b,c )∈ ℕ 3∗ prime in pairs, and f∈ ℕ ∗ , such that: ( a−b 2f ) 2 , ( c 2f ) 2 , ( a+b 2f ) 2 are in an arithmetic progression of reason n;And this problem is also equivalent to that of the existence of a non-trivial primitive integer right-angled triangle: a 2 + b 2 = c 2 , such that its area Δ= 1 2 ab=n f 2 , where f∈ ℕ ∗ , and this last equation can be written as follows, when using Pythagorician divisors: (1) Δ= 1 2 ab= 2 S−1 d e ¯ ( d+ 2 S−1 e ¯ )( d+ 2 S e ¯ )=n f 2;Where ( d, e ¯ )∈ ( 2ℕ+1 ) 2 such that gcd( d, e ¯ )=1 and S∈ ℕ ∗ , where 2 S−1 , d, e ¯ , d+ 2 S−1 e ¯ , d+ 2 S e ¯ , are pairwise prime quantities (these parameters are coming from Pythagorician divisors). When n=1 , it is the case of the famous impossible problem of the integer right-angled triangle area to be a square, solved by Fermat at his time, by his famous method of infinite descent. We propose in this article a new direct proof for the numbers n=1 (resp. n=2 ) to be non-congruent numbers, based on an particular induction method of resolution of Equation (1) (note that this method is efficient too for general case of prime numbers n=p≡a ( ( mod8 ) , gcd( a,8 )=1 ). To prove it, we use a classical proof by induction on k , that shows the non-solvability property of any of the following systems ( t=0 , corresponding to case n=1 (resp. t=1 , corresponding to case n=2 )): ( Ξ t,k ){ X 2 + 2 t ( 2 k Y ) 2 = Z 2 X 2 + 2 t+1 ( 2 k Y ) 2 = T 2 , where k∈ℕ;and solutions ( X,Y,Z,T )=( D k , E k , f k , f ′ k )∈ ( 2ℕ+1 ) 4 , are given in pairwise prime numbers.2020-Mathematics Subject Classification 11A05-11A07-11A41-11A51-11D09-11D25-11D41-11D72-11D79-11E25 .
文摘Ports play a fundamental role in a sustainable integration of Africa in International trade. Both importers and exporters, shipping companies and government, however face high cost for sea transport and substantial inefficiency in port operations. This has resulted in congestion, higher dwell time, higher costs which affect the competitive ability in sub regional and global economy. This study investigates the main factors explaining poor container handling operations and limited competitive ability in Cameroonian Ports and aggregating this to the competitive position of Cameroonian ports in the West and Central African sub-regions (WCA). Using Analytic Hierarchy Process (A.H.P), the paper seeks to provide a basic understanding of container transportation and port’s terminal operations problems (constraints & ineffectiveness) in Cameroon.