• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권11호
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• pp.2052-2067
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• 2011

Complementary trees are two spanning trees rooted at the sink node satisfying that any source node's two paths to the sink node on the two trees are node-disjoint. Complementary trees routing strategy is a special node-disjoint multi-path routing approach. Several complementary trees routing algorithms have been proposed, in which path discovery methods based on depth first search (DFS) or Dijkstra's algorithm are used to find a path for augmentation in each round of path augmentation step. In this paper, a novel path discovery method based on multi-tree-growing (MTG) is presented for the first time to our knowledge. Based on this path discovery method, a complementary trees routing algorithm is developed with objectives of low average path length on both spanning trees and low complexity. Measures are employed in our complementary trees routing algorithm to add a path with nodes near to the sink node in each round of path augmentation step. The simulation results demonstrate that our complementary trees routing algorithm can achieve low average path length on both spanning trees with low running time, suitable for wireless sensor networks in industrial scenarios.

• 대한교통학회지
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• 제19권5호
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• pp.85-97
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• 2001

최근 급격히 증가하고 있는 교통수요에 능동적으로 대처해 나가기 위해서는 도시 가로망이 도시교통환경에서 담당하는 교통기능을 체계적으로 분석하여 도로의 기능적 위계를 이루고, 제약된 예산 하에 최대의 효율을 누릴 수 있는 교통관리계획이나 시설계획을 수립해야 할 것이다. 그러나 기능적 위계의 설정 지표 중 중요도가 높은 차량의 운행경로는 조사상 불가능하거나 큰 어려움을 내포하고 있다. 이러한 문제점을 해결하기 위해 본 논문에서는 Simulation기법을 이용하여 차량의 운행경로 및 운행거리를 파악하였다. 이에 본 연구는 특정 경로에 유출입하는 교통량을 알 수 있는 경로OD교통량과 특정 경로내의 특정 노드(i, j)사이에 통과하는 경로교통량이라는 개념을 도입하였다. 이러한 통행량들을 분석하여 도시 가로망의 기능적 분류를 가능케 하는 정량적 지표를 정립하였으며, 더 나아가 효율적 투자계획 및 정책결정권자의 계획방향 판단에 일조할 수 있는 '집중관리구간' 선정영역을 제시하였다.

• 한국통신학회논문지
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• 제28권11B호
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• pp.972-984
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• 2003

본 논문에서는 MPLS 네트워크에서 LSP 설정에 적용될 수 있는 새로운 대역폭 보장 온라인 라우팅 알고리즘들을 제안하고 기존의 알고리즘들과 함께 그 성능을 시뮬레이션을 통해서 평가한다. 제안된 방식은 기존의 WSP나 SWP 알고리즘을 K-shortest loopless path 알고리즘에 기초해서 확장시킨 형태를 가진다. 시뮬레이션을 통해서 accepted bandwidth, accepted request number 그리고 average path length라는 성능을 평가한 결과, 모든 노드들이 LSP 설정의 ingress나 egress 노드가 될 수 있는 상황에서 제안된 방식들이 전반적으로 우수한 성능을 보였는데 네트워크 부하가 큰 경우에는 특히, 최소 홉 경로에 기초한 방식들이 좋은 성능을 보임을 알 수 있다.

• The Journal of the Acoustical Society of Korea
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• 제21권1E호
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• pp.25-30
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• 2002

We report on the development of a fiber optic hydrophone consists of a sensing Michelson interferometer and a compensating Mach-Zehnder interferometer for optical path length compensation. The double interferometer configuration has the following advantages: the hydrophone can be made more small; a laser source with a relatively short coherence length can be used; and the compensating interferometer can be located near the signal processing electronics, far away from the sensing interferometer and noise introduced by reference arm can be greatly reduced. The performance of the hydrophone is evaluated experimentally by immersing the sensing interferometer in a water tank to detect underwater acoustic signals generated by an acoustic wave projector. Experimental results show that over the frequency range of 1 to 4 kHz, the hydrophone has an almost flat response with an average normalized sensitivity of -302 dB re 1/ μ Pa.

• 경영과학
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• 제32권4호
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• pp.81-96
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• 2015

This paper models knowledge diffusion on an inter-organizational network. Based on literatures related to knowledge diffusion, the model considers critical factors that affect diffusion behavior including nodal property, relational property, and environmental property. We examine the relationships among network structure, knowledge search, and diffusion performance. Through a massive simulation runs based on the agent-based model, we find that the average path length of a network decreases a firm's cumulative knowledge stock, whereas the clustering coefficient of a firm has no significant relationship with the firm's knowledge. We also find that there is an interaction effect of network structure and the range of knowledge search on knowledge diffusion. Specifically, in a network of a larger average path length (APL) the marginal effect of search conduct is significantly greater than in that of a smaller APL.

• 한국정보과학회논문지:소프트웨어및응용
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• 제34권11호
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• pp.971-983
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• 2007

셀룰러 유전알고리즘(CGAs)은 모집단이 특정한 위상 구조를 갖는 유전알고리즘의 일종이다. 보통의 경우, CGAs의 모집단 공간은 네트워크 이론 측면에서 상대적으로 긴 평균경로길이와 큰 클러스터링계수를 갖는 정규 격자형 위상 구조이다. 평균경로길이가 길면 멀리 떨어진 개체들 사이의 유전적 상호작용이 느리게 일어난다. 따라서 클러스터링계수를 유지하면서 평균경로길이를 줄인다면 개체의 다양성이 유지되면서도 모집단이 보다 빠르게 수렴할 것이다. 이 논문에서는 최소좁은세상 셀룰러 유전알고리즘(SSWCGAs)을 제안한다. SSWCGAs에서 각 개체는 클러스터링이 잘되었으면서도 노드를 연결하는 평균경로길이가 짧은 모집단에 거주하여, 클러스터링에 의한 세부탐색 능력을 유지하면서도 전역탐색을 잘하게 된다. 네 가지 실변수 함수와 두 가지 GA-hard 문제에 대한 실험을 통하여 SSWCGAs가 SGAs 및 CGAs보다 효과적임을 보였다.

• 응용통계연구
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• 제29권7호
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• pp.1445-1458
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• 2016

본 논문에서는 1976년부터 2015년까지 40년 간, 59개 지역 기온 시계열을 대상으로 degrended cross-correlation analysis(DCCA) 방법을 이용한 상관 계수를 도출하였다. 4년 단위의 평균기온, 최고기온, 최저기온 시계열을 분석하여 상관계수 값이 0.9 이상이면 단위 기간 동안 두 지역의 온도 상관성이 존재하는 것으로 판단하고, 두 지역 간의 연결선을 만드는 방식으로 네트워크를 구축하였다. 이후 네트워크 이론을 바탕으로 평균 경로 길이, 결집 계수, 유사성, 모듈성 등의 값들을 도출하였다. 그 결과, 기온 네트워크는 좁은 세상 성질을 만족하고, 유사성과 모듈성이 높은 네트워크임을 알 수 있었다.

• 한국작물학회지
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• 제45권4호
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• pp.245-250
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• 2000

This study was conducted to analyze the responses of some agronomic traits to the different cultural environments and relations among the agronomic traits for selecting sesame varieties with higher cultural stabilities. The indexes for stability parameters measured were coefficient of variability, heritabilities, genetic correlations and path coefficients of agronomic traits according to locations and years in Korea. The heritabilities of agronomic traits showed different by locations and years. Number of seeds per capsule and 1000 seeds weight showed higher heritabilities, but stem length and seed weight per plant showed relatively lower heritabilities. Average heritabilities of some agronomic traits in 1998 were comparatively higher than those of 1999. Of six areas, Jinju area showed biggest coefficient of yield variability in 1998-1999. Iksan and Taegu areas showed higher heritabilities in 1998, but Iksan and Jinju areas showed lower heritabilities in 1999. Genetic correlations were slightly higher than corresponding phenotypic correlations. Stem length showed positive genetic correlation with the number of capsules per plant, and seed weight per plant and the number of capsule per plant showed positive genetic correlation with seed weight per plant. On the analysis of path coefficients, stem length and number of capsules effected highly on grain yield. Great regional variations were observed on the effects of agronomic traits on grain yield. Higher direct effects of stem length on grain yield were observed at Suwon, Chungwon, Taegu, Jinju and Naju areas, but in Iksan area was observed higher direct effect of the number of capsules per plant on grain yield in 1998. In 1999, higher direct effect of stem length on grain yield was observed at Chungwon and Suwon areas. Iksan and Taegu areas were also observed higher direct effect of the number of capsule per plant on grain yield.

• 한국학교ㆍ지역보건교육학회지
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• 제20권2호
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• pp.69-80
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• 2019

Objectives: In this study, we tried to analyze the factors affecting Length Of Stay for serious patients in Republic of Korea. Methods: The study included 139,172 serious patients in the 2012-2016 discharge details. Using the SPSS 23.0 program, we conducted a rank regression analysis with social and social demographic characteristics as control variables, medical institution characteristics and medical use characteristics as independent variables, and Average Length Of Stay as a dependent variable. Results: Average Length Of Stay for participants was found to be 9.92days. And the location and bed size of medical institutions were not statistically significant, the hospitalization path was more urgent(B=0.43) than the outpatient (p<0.001), and there was no secondary diagnosis(B=0.35). However, Average Length Of Stay was higher (p<0.001) than there was no main surgery(B=0.80). After discharge, Average Length Of Stay for funding(B=0.43) and death(B=0.72) was long (p<0.001). Average Length Of Stay for participants was found to be 9.92days. And the location and the bed size of the medical institution were not statistically significant, and the hospitalization pass had longer Length Of Stay for emergency patients(B=0.43) than for outpatients(p<0.001). There was a longer Length Of Stay(B=0.35) than none was diagnosed. There were longer Length Of Stay(p<0.001) than there was no major surgery(B=0.80). After discharge, the outpatients had longer Average Length Of Stay(B=0.43) and deaths(B=0.72) than those who returned home(p<0.001). Conclusion: As a result of analyzing the factors affecting Average Length Of Stay of the participants, it was confirmed that regardless of the location and bed size of medical institutions, hospitalization route, department diagnosis, main surgery, and whereabouts after discharge. Therefore, appropriate interventions and necessary support must be provided so that efficient Length Of Stay can be managed according to the medical use characteristics of serious patient.

• The Journal of Korean Physical Therapy
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• 제25권3호
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• pp.136-142
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• 2013

Purpose: The application of transcutaneous electrical nerve stimulation (TENS) is beneficial for joint movements, inhibition of spasticity, and the improvement of walking ability in patients with chronic hemiplegia. This study aimed to identify the effect of the application of TENS to the knee extensor on the affected side with respect to postural-sway distance and velocity during the sit-to stand movement. Methods: We included 19 patients with post-stroke hemiplegia in this study. They underwent measurements during the sit-to stand movement on a force plate with 5 different stimulation dosages applied over 7 s:No TENS, high-frequency and high intensity TENS, high-frequency and low intensity TENS, low-frequency and high intensity TENS, and low-frequency and low intensity TENS The 5 different condition were administered in random order. Results: The group that received TENS application exhibited a significant decrease in path length and average velocity of center of pressure (COP) displacement compared with the group that did not receive TENS application. TENS dosage at low frequency (3Hz) and high intensity yielded a significant decrease in path length, average velocity, mediolateral distance and anteroposterior distance of COP displacement (p<0.05). Conclusion: Our results demonstrated the effectiveness of the application of low-frequency TENS on STS performance. These findings provide useful information on the application of TENS for the reduction of postural sway during the sit-to-stand movement after stroke.