A Numerical Model for Nuclide Migration in the Far-field of the Repository

Lee, Youn-Myoung,Lee, Han-Soo,Park, Heui-Joo,Cho, Won-Jin,Han, Kyong-Won,Park, Hun-Hwee Korean Nuclear Society 1989 Nuclear Engineering and Technology Vol.21 No.4

A numerical model for nuclide migration through fractured rock media has been developed. Nuclide transport with groundwater in rock fissures and the diffusion of nuclides into rock matrix are considered one-dimensionally . In the safety assessment of the repository for radioactive waste, this one-dimensional model by the finite-difference scheme, which enables us not only to use more realistic boundary conditions but also to model the nonhomogeneous rock medium as the multilayered media, can be used effectively with the analytical mode. The solution by the numerical model will be verified analytically, and then extended to the double-layered rock medium transport model.

Effect of Various Leg-Crossing Positions on Muscle Activities of Rectus Femoris, Tensor Fascia Latae, and Hamstring in Healthy 20's Adults

Lee, Won-Hwee,Kang, Tae-Hee,Kim, Jeong-Ha,suryanti, Tri 대한물리치료학회 2015 대한물리치료학회지 Vol.27 No.5

Purpose: The purpose of this study was to investigate the effect of leg-crossing positions on muscle activities of rectus femoris, tensor fascia latae, and hamstring in healthy 20's adults. Methods: Twenty healthy subjects were asked to perform three leg-crossing positions, leg crossing (LC), tailor crossing (TC), and ankle crossing (AC). Surface electromyography (EMG) was used to evaluate the activities of rectus femoris, tensor fascia latae, and hamstring during upright sit posture (UP) and three leg-crossing positions and UP was compared to three leg-crossing positions. Repeated one way ANOVA was used for data analysis. The alpha level was set at 0.05. Results: The results showed significant difference in the muscle activities of rectus femoris, tensor fascia latae, and hamstring among leg-crossing positions. The muscle activity of the rectus femoris was significantly lower in LC and TC positions than UP. The muscle activity of tensor fascia latae was significantly higher in LC position than UP and other leg-crossing positions. The muscle activity of hamstring was significantly higher in LC and TC positions and significantly lower in AC position than in UP. Conclusion: Our study suggests that the activity of hip muscles was affected by pelvic and knee alignment in various leg-crossing positions.

Genetic Distribution Pattern of Bluegill Sunfish Lepomis macrochirus in Freshwater Ecosystems across Korea

Hwee Hui Lau,Jingting Huang,Ye-Seul Kwan,Wan-Ok Lee,Yong-Jin Won 한국동물분류학회 2009 Animal Systematics, Evolution and Diversity Vol.25 No.3

Lepomis macrochirus from the family Centrarchidae, commonly known as Bluegill sunfish, is an introduced freshwater fish in Korea that thrives in lakes, ponds, reservoirs and rivers. Since its introduction into Korea in 1969, Lepomis macrochirus has rapidly dispersed out and increased in number almost all over the freshwater ecosystems in Korea. Consequently this species causes a severe ecological problem, threatening native fishes due to its omnivorous foraging behaviors upon fish juveniles and many freshwater invertebrates. To address population genetic structure of L. macrochirus, 74 fish samples from 10 populations were collected and compared for their mitochondrial D-loop control region. As the result we found that the genetic diversity of L. macrochirus is extremely low such as resulting only four haplotypes with a few nucleotide differences among them. Analysis of molecular variance (AMOVA) revealed that the source of population genetic variation is largely retained in the comparisons among individuals within populations, while it is relatively low with slight significance at the highest hierachical group. This distribution pattern differs from what is expected when biogeography is under the influence of natural geographic barriers such as mountain ranges in Korea. Instead the result is accord with the influential role of random spreading events facilitated by local people for aquaculture and fishing, and subsequent dispersals since its single point of introduction ito Korea.

A Study on the Migration Characteristics of Cs-137 in a Packed Column

Lee, Jae-Owan,Cho, Won-Jin,Han, Kyung-Won,Park, Hun-Hwee Korean Nuclear Society 1990 Nuclear Engineering and Technology Vol.22 No.1

In this study the migration experiment using packed column with crushed tuff was conducted as a basic research to develop migration model of radionuclides through geologic media. The main emphasis was put on evaluating the validity of migration models. For this, two models were introduced: one is the model which is based on the assumption of instantaneous equilibrium reaction and the other the model based on kinetic process such as intraparticle diffusion. The coefficient of hydrodynamic dispersion in packed column was determined using iodine as nonsorbing tracer. The hydrodynamic dispersion coefficient, D$_{L}$ was shown to be 0.11$\times$10$^{-2}$ $\textrm{cm}^2$/min under the condition of the column porosity of 0.483 and the average water velocity of 0.915$\times$10$^{-2}$ cm/min. The distribution coefficient, Kd of Cs-137 on crushed tuff was 11.3 cc/g at the concentration of 2$\times$10$^{-6}$ M and the temperature of 2$0^{\circ}C$. The breakthrough curve of Cs-137 through packed column was shown to have an asymmetric curve in which long trailing tail appears at the end part of the curve. The results obtained from the comparison of introduced models with experimental data indicated that the mass transfer model with intraparticle diffusion as rate-controlling step simulated the behaviors of Cs-137 migration more adequately, when compared with the bulk reaction model in which the assumption of instantaneous equilibrium reaction was maded. Consequently, the intraparticle diffusion was found to be an important factor in the migration of Cs-137 through packed column.n.

Effect of Various Leg-Crossing Positions on Muscle Activities of Rectus Femoris, Tensor Fascia Latae, and Hamstring in Healthy 20`s Adults

( Won-hwee Lee ),( Tae-hee Kang ),( Jeong-ha Kim ),( Tri Suryanti ) 대한물리치료학회 2015 대한물리치료학회지 Vol.27 No.5

Purpose: The purpose of this study was to investigate the effect of leg-crossing positions on muscle activities of rectus femoris, tensor fascia latae, and hamstring in healthy 20`s adults. Methods: Twenty healthy subjects were asked to perform three leg-crossing positions, leg crossing (LC), tailor crossing (TC), and ankle crossing (AC). Surface electromyography (EMG) was used to evaluate the activities of rectus femoris, tensor fascia latae, and hamstring during upright sit posture (UP) and three leg-crossing positions and UP was compared to three leg-crossing positions. Repeated one way ANOVA was used for data analysis. The alpha level was set at 0.05. Results: The results showed significant difference in the muscle activities of rectus femoris, tensor fascia latae, and hamstring among leg-crossing positions. The muscle activity of the rectus femoris was significantly lower in LC and TC positions than UP. The muscle activity of tensor fascia latae was significantly higher in LC position than UP and other leg-crossing positions. The muscle activity of hamstring was significantly higher in LC and TC positions and significantly lower in AC position than in UP. Conclusion: Our study suggests that the activity of hip muscles was affected by pelvic and knee alignment in various leg-crossing positions.

Effect of a Workplace-Based Work-Conditioning Program on Management of Work-Related Musculoskeletal Disorders

Won-hwee Lee,Sung-min Ha,Su-jung Kim,Kyue-nam Park,Sung-dae Cheong,Si-hyun Kim,Jong-hyuck Weon,Heon-seock Cynn,Oh-yun Kwon 한국전문물리치료학회 2010 한국전문물리치료학회지 Vol.17 No.4

The purpose of this study was to investigate the effects of a workplace-based work-conditioning program (WCP) on the management of work-related musculoskeletal disorders (WRMDs) in an automo-bile-parts manufacturing company. In total, 1,110 subjects with WRMDs participated in workplace-based WCP emphasizing function-centered management and ergonomics. We investigated the incidence of WRMDs variables (number of persons diagnosed with industrial accident-related WRMDs, number of cases of WRMD) and financial benefits (cost of workers' compensation insurance and lost work days related to WRMDs) per year before and after WCP. Additionally, we compared self-reported pain intensity and functional disability in subjects with musculoskeletal pain before and after the WCP. Pain intensity was measured using a visual analog scale (VAS), and functional disability was measured by the neck disability index (NDI) and the Oswestry disability Index (ODI). The number of person diagnosed with in dustrial accident-related WRMDs, the number of cases of WRMD, the cost of workers' compensation in surance and lost work days related to WRlVIDs per year decreased by 51%, 37%, 34%, and 47%, respectively, and VAS, NDI, and am scores decreased significantly after implementation of WCP (p

Role of nuclear mechanosensitivity in determining cellular responses to forces and biomaterials

Lee, Jung-Hwan,Kim, Dong-Hwee,Lee, Hae-Hyoung,Kim, Hae-Won Elsevier 2019 Biomaterials Vol.197 No.-

<P><B>Abstract</B></P> <P>Tissue engineers use biomaterials or apply forces to alter cell behaviors and cure damaged/diseased tissues. The external physical cues perceived by cells are transduced intracellularly along the mechanosensitive machineries, including subcellular adhesion molecules and cytoskeletons. The signals are further channeled to a nucleus through the physical links of nucleoskeleton and cytoskeleton or the biochemical translocation of transcription factors. Thus, the external cues are thought to affect directly or indirectly the nucleus and the genetic transcriptional process, ultimately determining cell fate. Here we communicate the importance of such mechanotransductory processes in cell and tissue engineering where external forces- or biomaterials-related physical cues essentially regulate cellular behaviors, with an emphasis on the mechanosensing and signaling along the road to a nucleus.</P>

의자 좌면 높이가 척추 세움근과 근 활성도에 미치는 영향

이원휘(Won-Hwee Lee) 한국산학기술학회 2017 한국산학기술학회논문지 Vol.18 No.7

본 연구는 의자 좌면 높이가 척추 세움근과 배곧은근의 근 활성도에 어떠한 영향을 미치는지 알아보고자 실시하였다. 건강한 남녀 30명을 대상으로 세 가지 높이의 의자 좌면에 앉게 하고 양쪽 척추 세움근과 배곧은근의 근활성도를 표면 근전도 장비를 사용하여 측정하였다. 반복측정된 일요인 분산분석을 통해 세 가지 높이의 의자 좌면에 따른 근활성도의 차이를 비교하였고 유의수준(a)은 0.05로 설정하였다. 연구 결과 의자 좌면 높이에 따라 양쪽 배곧은근의 근활성도는 유의한 차이를 보였고 양쪽 척추 세움근의 근활성도는 유의한 차이가 없었다. 양쪽 배곧은근은 낮은 높이의 의자 좌면에서 정상 높이와 높은 높이의 좌면에 비해 근활성도가 유의하게 증가하였다. 본 연구결과를 통해 앉은 자세에서 의자 좌면의 높이는 배곧은근의 근 활성도에 영향을 줄 수 있으며 배곧은근의 근활성도 증가는 요통과 같은 근골격계 통증을 일으킬 수 있으므로 근골격계 통증을 예방하기 위해 바르게 앉은 자세와 함께 의자 좌면 높이는 중요하다. This study examined the effects of the seat height of a chair on the muscle activity of the erector spinae and rectus abdominis. Thirty healthy subjects were asked to sit on chairs at three different seat heights. The muscle activities of both the erector spinae and rectus abdominis were measured by surface electromyography. The data were analyzed by repeated one way ANOVA and the muscle activity was compared according to the seat height. The alpha level was set to 0.05. The results showed that the muscle activities of the erector spinae were not significantly different among the three seat heights. The muscle activities of the rectus abdominis were significantly different among the three seat heights. Both the rectus abdominis muscle activities were significantly greater in the low seat height than the other seat heights. These results showed that the seat height of the chair affects the muscle activities of the rectus abdominis muscle, leading to musculoskeletal pain, such as low back pain. Therefore, the seat height of a chair with a correct sitting position is important for preventing musculoskeletal pain.

컴퓨터 작업시 책상과 체간사이 거리가 전방 머리 자세와 목과 어깨 근육들의 근 활성도에 미치는 영향

이원휘 ( Won Hwee Lee ) 대한물리의학회 2013 대한물리의학회지 Vol.8 No.4

PURPOSE: The purpose of this study was to investigate the effect of distance between trunk and desk on forward head posture and muscle activity of neck and shoulder muscles during computer work. METHODS: Twenty subjects who have healthy conditions were asked to perform computer work in two conditions (distance between trunk and desk was 0 and 15 cm). Forward head angle was analyzed with a SIMI motion analysis system. Surface electromyography recorded the upper trapezius and splenius capitis muscles. The significance of differences in distance between trunk and desk (0cm and 15cm) was tested by paired t-test. The alpha level was set at .05. RESULTS: The results showed that the change of forward head angle was significantly higher during the computer work when the distance between trunk and desk was 15cm than 0cm. The muscle activity of upper trapezius and splenius capitis was also significantly higher during the computer work when the distance between trunk and desk was 15cm than 0cm. CONCLUSION: Our study suggest that the distance between trunk and desk was should minimized for prevention of forward head posture during computer work.

견관절 외전 각도에 따른 중간 및 하부 승모근의 근 활성도 비교

이원휘 ( Won Hwee Lee ),하성민 ( Sung Min Ha ),박규남 ( Kyue Nam Park ),김수정 ( Su Jung Kim ),원종혁 ( Jong Hyuck Won ),최흥식 ( Houng Sik Choi ) 한국전문물리치료학회 2011 한국전문물리치료학회지 Vol.18 No.1

The purpose of this study was to compare electromyography (EMG) activity for the middle and lower trapezius muscle according to various shoulder abduction angles. Thirty healthy male subjects were recruited for this study. Each subject performed three repetitions of horizontal abduction at 75°, 90°, 125°, 160°, and 180° of shoulder abduction angle in a prone position. Surface EMG activity was recorded from the middle and lower trapezius while the subjects held for five seconds at a predetermined position. The EMG activity was normalized using the maximal voluntary isometric contraction (MVIC) elicited using a manual muscle testing technique. A repeatedly measured ANOVA was performed by Bonferroni`s post hoc test. The EMG activity of the middle and lower trapezius was significantly different among shoulder abduction angles (p<.05). The greatest level of muscle activity for the middle and lower trapezius were demonstrated at 90° and 160° of shoulder abduction angle, respectively. These results suggest that middle and lower trapezius strengthening exercise and manual muscle testing should be performed at different shoulder abduction angles.