• Title/Summary/Keyword: distance functions

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The Influence of Accommodation on Watching Home 3D TV at Close Distance (가정용 3D TV의 근거리 시청이 조절기능에 미치는 영향)

  • Kim, Jung-Ho;Hwang, Hae-Young;Kang, Ji-Hun;Yu, Dong-Sik;Kim, Jae-Do;Son, Jeong-Sik
    • Journal of Korean Ophthalmic Optics Society
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    • v.18 no.2
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    • pp.157-163
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    • 2013
  • Purpose: This study was investigated weather watching 2D and 3D images effecting on accommodative function (AF), and differences between changes of AF by 2D and 3D. Methods: 50 subjects (male 30, female 20) aged 20's to 40's years old ($22.9{\pm}3.93$ years) who are available to watching 3D images were participated for this study. Accommodative amplitude (AA) by near point of accommodation (NPA), accommodative response (AR), positive and negative relative accommodation (PRA, NRA), accommodative facility (AF) were measured before, after watching 2D and 3D images at 1 m distance for 30 minutes respectively. Results: Accommodative amplitude after both watching 2D and 3D images decreased comparing to before watching images, and AA after watching 3D images was significantly lower than after watching 2D images. AR after both watching 2D and 3D images increased comparing to before watching images, but there was no difference between 2D and 3D. PRA and NRA were not significantly different between before, after watching 2D and 3D images. Accommodation speed by AF was increased for before watching ($13.52{\pm}3.32$ cpm) following by for after watching 2D images ($14.28{\pm}3.21$ cpm) and for watching 3D images ($14.90{\pm}3.27$ cpm). Conclusions: Watching images at close distance is effect to accommodation functions, and sequence of AA decrease of before watching images following by after watching 2D images and after watching 3D images may effect to asthenopia with same sequence as AA decrease. The results of increase of AF after watching images, specially 3D images show a possibility of vision therapy and further detail VT studies using 3D images are required in the future.

Effect of Satisfaction in Neighborhood Park Environments on Physical Activity and Health - The Case of Seongsan-gu and Uichang-gu in Changwon City - (근린공원 환경의 만족도가 신체활동과 건강에 미치는 영향 - 창원시 성산구와 의창구를 대상으로 -)

  • Park, Kyung-Hun;Lee, Woo-Sung;Kim, Tae-Hwan;Kim, Eun-Jung
    • Journal of the Korean Institute of Landscape Architecture
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    • v.42 no.3
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    • pp.64-75
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    • 2014
  • The purpose of this study is to analyze the effects of satisfaction in neighborhood park environments located in the Changwon-si of Gyeongsangnam-do, South Korea, on physical activity, the number of parks used for health improvement, and health levels based on Body Mass Index(BMI). Accordingly, a survey was conducted of 429 nearby residents and users of eight neighborhood parks located in urban areas of Seongsan-gu and Uichang-gu in the Changwon-si. The correlation between the environmental perception of neighborhood parks and physical activity and health, which was observed in the survey results, was analyzed using one-by-one linear regression analysis. By summarizing the study results, it was found that the primary reasons for avoiding park use were lack of time, time and effort required to reach the park(i.e., distance from the park), and lack of facilities within the park. Conversely, the primary reasons for using the park included accessibility, walking or strolling, leisure facilities, trees or shade, and diversity in exercise areas. In the case of park users, walking or strolling was the most common activity in the park. On average, park users walked to the parks for 10 minutes and exercised for an hour at least twice per week. With respect to the physical environment of the parks and surrounding areas, park users showed a high level of satisfaction with the distance between their houses and parks and the street environment. On the contrary, they exhibited low levels of satisfaction with water spaces and sightseeing within the parks. Subsequently, it was shown that the number of people using the parks for physical activities and health improvement was positively influenced(within a 5% significance level) by the intent to use the park for exercise, time spent in the park, satisfaction with park use and health improvement, distance to the park, and the convenience of using the park for the elderly. However, only the health improvement gained from park use was found to exhibit a correlation with BMI at the 10% significance level. Continuous accumulation of practical case studies on physical activities in parks and their health improvement effects is required. Through this, park spaces that are under the threat of reduction or elimination owing to various development plans can be conserved and expanded. Furthermore, such case studies can be used to provide data as the basis for deriving park plans and designs that improve parks' functions as sites of physical activity and health improvement.

An Ultrastructural Study on the Parotid Acinar Cells of X-irradiated Rats (X-선 조사를 받은 흰쥐 귀밑샘 샘포의 미세구조)

  • Yang, Nam-Gil;Park, In-Kyu;Ahn, E-Tay;Ko, Jeong-Sik;Park, Kyung-Ho;Kim, Jin-Gook
    • Applied Microscopy
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    • v.24 no.1
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    • pp.28-40
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    • 1994
  • Xerostomia and xerophthalmia are delicate or serous side effects, occuring when the radiotherapy is administered to the head and neck cancer patient. It is known that the cause of the above side effect is radiosensitivity of serous cells. In this study, the ultrastructural features of the parotid glands of the X-irradiated rats were observed. Sprague-Dawley rats weighing 200-250g each were anesthetized with sodium thiopental, and placed on the Mitsubishi linear accelerator. Only the head and neck areas of animals were exposured at the distance of 80cm, within the area of $30X30cm$, in the depth of 1cm, with the speed of 200R/min. Total doses applied were 3,000R or 6,000R depending on the experimental groups. Animals were sacrificed on the 6th hour, 2nd day and 6th day after the irradiation. Parotid glands were fixed in the 2.5% glutaraldehyde-1.5% paraformaldehyde solution, and followed by refixation in the 1% osmium tetroxide solution. Dehydrated blocks were embedded in araldite mixture, and ultrathin sections were cut. Sections were contrasted with the solution of uranyl acetate and lead citrate, and observed with JEM 100 CX-II electron microscope. The results were as follows: 1. Normal parotid acinar cells are two types; the light and the dark acinar cells. The light acinar cell contains dense secretory granules, whereas dark acinar cells contains granules of medium density with some darker spots within them, or other cells contain granules of medium density with darker rims. 2. Six hours after the irradiation, many acinar cells were degenerated showing variable stages of cytolytic bodies, light bodies, or dense degenerations. Within the acinar cell, Golgi apparatus and granular endoplasmic reticula were most severely altered elements. Granules showed more contrasting densities and irregularities. 3. Two days after the irradiation, some cytolytic bodies, and focal lucent degeneration of cytoplasm, and fine granular alteration of cytoplasmic matrix were pronounced. But other elements including secretory granules are rather looked unlatered. 4. Six days after the irradiation, most severe alterations were seen. Many intracellular canaliculi (or secretion figures), quanta of cytoplasm containing secretion antecedants, severely irregular luminal border, and again contrasting density of secretory granules showing tigroid spots or dense rims were noted. And myoepithelial degenerations were observed not uncommonly. 5. Irregular densities of secretory granules were interpreted as abnormal components of protein or carbohydrate portion are synthesized or abnormally metabolized under severe X-irradiation. 6. Myoepithelial degeneration and related alteration of nerve endings, etc., were suggested as the other causes of xerostomia following X-irradiation. 7. It is requested that radiation doses should be arranged, considering in mind not only the sensitivity of acinar cells but also the myoepithelial and neural functions.

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Space Debris Tracking Coverage Analysis of Spinning Disk for Optical Path Switch of Geochang Laser Tracking System (거창 레이저 추적 시스템의 광 경로 전환을 위한 회전 디스크의 우주쓰레기 레이저 추적 성능 분석)

  • Sung, Ki-Pyoung;Lim, Hyung-Chul;Yu, Sung-Yeol;Choi, Man-Soo;Ryou, Jae-Cheol
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.48 no.5
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    • pp.391-399
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    • 2020
  • KASI (Korea Astronomy and Space Science Institute) has been developing the multipurpose laser tracking system with three functions of satellite laser tracking, adaptive optics and space debris laser tracking for scientific research and national space missions. The space debris laser tracking system provides the distance to space debris without a laser retro-reflector array by using a high power pulse laser, which employs a spinning disk to change the optical path between the transmit and receive beams. The spinning disk causes the collision band which is unable to reflect the returned signal to a detector and then has an effect on the tracking coverage of space debris. This study proposed the mathematical model for tracking coverage by taking into account the various specifications of spinning disk such as disk size, spinning velocity and collision rate between the disk and hole. In addition, the spinning disk specifications were analyzed in terms of tracking coverage and collision band based on the mathematical model to investigate tracking requirements of the Geochang laser tracking system.

Similarity of Zooplankton Community Structure among Reservoirs in Yeongsan-Seomjin River Basin (영산강, 섬진강 수계 내 주요 저수지에 대한 동물플랑크톤 군집 구조의 유사성 분석)

  • Ko, Eui-Jeong;Kim, Gu-Yeon;Joo, Gea-Jae;Kim, Hyun-Woo
    • Korean Journal of Ecology and Environment
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    • v.52 no.4
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    • pp.285-292
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    • 2019
  • Our study was based on the long-term surveys with respect to the major reservoirs located in the Yeongsan and Seomjin river basins. A total of 45 survey sites have been surveyed four times a year from 2008 to 2017. We identified 166 zooplankton species, including 127 rotifers, 26 cladocerans, and 13 copepods. Mean population density and species number of small reservoirs were higher than those of mid and large reservoirs. Considering outliers exceeding the 90th percentile between species occupancy and mean abundance, 10 of 11 habitat generalists were rotifers, and Bosmina longirostris was the only cladoceran. Habitat specialist consisted of three species of rotifers and emerged from one to three survey sites. According to the modularity results, it was found that the survey sites covering the entire river basins were characterized into five groups, which was similar to the classification by maximum water surface areas(MWSA). The result of the eigenvector centrality showed that the size of MWSA had a greater impact on the similarity of zooplankton community structure between reservoirs than the difference in distance between reservoirs. In the case of survey points in near dam or estuary bank of Juam and Youngsan reservoirs, modularity class were separated from other internal survey points of those. Given that the zooplankton interactions may contribute to freshwater functions more than species diversity. These topological features provide new insight into studying zooplankton distribution patterns, their organization and impacts on freshwater-associated function.

Selection of the Priority Order for Additional Green Spaces for Urban Park and Green Network (공원녹지 네트워크 구축을 위한 추가녹지 조성 우선순위 선정)

  • SaGong, Jung-Hee;Ra, Jung-Hwa;Cho, Hyun-Ju
    • Journal of the Korean Institute of Landscape Architecture
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    • v.34 no.6 s.119
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    • pp.10-21
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    • 2007
  • The purpose of this paper was to classify areas demanding to be transformed to green spaces and evaluate their grades for urban park and green networks. The results of this study are summarized below; 1. The results of the classified green spaces in the research areas fall into three types including children parks, neighborhood parks, and public green spaces. The three types of green spaces were analysed with recreational indexes. The zones disturbing the green-networks were sorted out. These zones should be changed into a supplementary green spaces for improving the recreational functions in the city. 2. For urban park and green networks, distances between the parks and size of the parks were adopted as indices. Based on the index of distances between the parks, disturbing zones were evaluated with 3 grades. The first grade includes primary industrial complexes and housing complexes. The second grade was observed mostly in industrial complex areas. The third grade includes housing complexes. Based on the indexes of size of parks, disturbing zones were evaluated with 2 grades. In the case of grade I, it appeared in housing complex. In the case of grade II, it appeared in industrial complex. 3. Then, we prioritized the disturbing zones with severity in order to make supplementary green spaces. Through the process, the zones of the grade I for two each recreational index were evaluated to two grades. The analysis results of evaluated zones were that grade II appeared over industrial and housing complexes widely. Grade I appeared over housing complexes. 4. It is necessary that the grade of disturbing zones should be considered as an order to make green spaces to supplement a green-network. For this, we formed a basic frame of a green-networks in Dalsu-Gu and placed the disturbing zones on the basic frame of a green-network. Consequently, The results were that the green-networks in Dalsu-Gu was composed on four green-network axes and its shape mirrored a cruciform (+) of northwest$\leftrightarrow$southeast direction and southwest$\leftrightarrow$northeast direction.

The Study on Effects of After Vision Training for Elementary School Children in Muan (무안군 소재 초등학생들의 시훈련 효과에 관한 연구)

  • Jang, Jung Un;Kim, In Suk
    • Journal of Korean Ophthalmic Optics Society
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    • v.18 no.2
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    • pp.137-142
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    • 2013
  • Purpose: This study was designed to investigate the current status of visual acuity for elementary school students in Muan-gun and to analyze improvements of their visual function after vision training for the elementary school students who have either insufficiency of accommodation or vergence. Methods: Subjective refraction, objective refraction and binocular function were examined for 335 elementary school children from year 1 to year 6 live in Muan area, and then 47 students who have symptoms of binocular dysfunction among them were selected. We analyzed and compared between before and after vision training (VT) in binocular vision function results. Results: The results show that most of the subjects had much problem in near point convergence (NPC) than accommodation. After the vision training, the average of subjects NPC was improved about 5.93 cm, from $11.57 {\pm}1.850$ cm for before VT to $5.66{\pm}0.965$ cm for after VT. After VT positive fusional vergence at near distance after VT was $19.64{\pm}3.66$ $\Delta$, which was as much as double of near phoria. Accommodative amplitude was improved from $10.02{\pm}2.566$ D for before VT to $12.30{\pm}1.397$ D for after VT, which similar to mean of expected accommodative amplitude of 11.27 years old. Conclusions: Among insufficiency of accommodation and vergence NPC was improved specially, and accommodative facility and other ocular functions were also improved. Therefore, it is considered the vision training is very effective to recover from visual function problems.

Application of the JMA instrumental intensity in Korea (일본 기상청 계측진도의 국내 활용)

  • Kim, Hye-Lim;Kim, Sung-Kyun;Choi, Kang-Ryong
    • Journal of the Earthquake Engineering Society of Korea
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    • v.14 no.2
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    • pp.49-56
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    • 2010
  • In general, the seismic intensity deduced from instrumental data has been evaluated from the empirical relation between the intensity and the PGA. From the point of view that the degree of earthquake damage is more closely associated with the seismic intensity than with the observed PGA, JMA developed the instrumental seismic intensity (JMA instrumental intensity) meter that estimate the real-time seismic intensity from the observed strong motion data to obtain a more correct estimate of earthquake damage. The purpose of the present study is to propose a practical application of the JMA instrumental intensity in Korea. Since the occurrence of strong earthquakes is scarce in the Korean Peninsula, there is an insufficiency of strong motion data. As a result, strong motion data were synthesized by a stochastic procedure to satisfy the characteristics of a seismic source and crustal attenuation of the Peninsula. Six engineering ground motion parameters, including the JMA instrumental intensity, were determined from the synthesized strong motion data. The empirical relations between the ground motion parameters were then analyzed. Cluster analysis to classify the parameters into groups was also performed. The result showed that the JMA acceleration ($a_0$) could be classified into similar group with the spectrum intensity and the relatively distant group with the CAV (Cumulative Absolute Velocity). It is thought that the $a_0$ or JMA intensity can be used as an alternative criterion in the evaluation of seismic damage. On the other hand, attenuation relation equations for PGA and $a_0$ to be used in the prediction of seismic hazard were derived as functions of the moment magnitude and hypocentral distance.

Enhancement of the Chaperone Activity of Alkyl Hydroperoxide Reductase C from Pseudomonas aeruginosa PAO1 Resulting from a Point-Specific Mutation Confers Heat Tolerance in Escherichia coli

  • Lee, Jae Taek;Lee, Seung Sik;Mondal, Suvendu;Tripathi, Bhumi Nath;Kim, Siu;Lee, Keun Woo;Hong, Sung Hyun;Bai, Hyoung-Woo;Cho, Jae-Young;Chung, Byung Yeoup
    • Molecules and Cells
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    • v.39 no.8
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    • pp.594-602
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    • 2016
  • Alkyl hydroperoxide reductase subunit C from Pseudomonas aeruginosa PAO1 (PaAhpC) is a member of the 2-Cys peroxiredoxin family. Here, we examined the peroxidase and molecular chaperone functions of PaAhpC using a site-directed mutagenesis approach by substitution of Ser and Thr residues with Cys at positions 78 and 105 located between two catalytic cysteines. Substitution of Ser with Cys at position 78 enhanced the chaperone activity of the mutant (S78C-PaAhpC) by approximately 9-fold compared with that of the wild-type protein (WT-PaAhpC). This increased activity may have been associated with the proportionate increase in the high-molecular-weight (HMW) fraction and enhanced hydrophobicity of S78C-PaAhpC. Homology modeling revealed that mutation of $Ser^{78}$ to $Cys^{78}$ resulted in a more compact decameric structure than that observed in WT-PaAhpC and decreased the atomic distance between the two neighboring sulfur atoms of $Cys^{78}$ in the dimer-dimer interface of S78C-PaAhpC, which could be responsible for the enhanced hydrophobic interaction at the dimer-dimer interface. Furthermore, complementation assays showed that S78C-PaAhpC exhibited greatly improved the heat tolerance, resulting in enhanced1 survival under thermal stress. Thus, addition of Cys at position 78 in PaAhpC modulated the functional shifting of this protein from a peroxidase to a chaperone.

A Case Study on the Clinical Application of Lee Silverman Voice Treatment-BIG (LSVT-BIG) Program for Occupational Performance and Motor Functions of Stroke Patients (뇌졸중 환자의 작업수행과 운동기능을 위한 Lee Silverman Voice Treatment-BIG(LSVT-BIG) 프로그램의 임상적용에 대한 사례연구)

  • Jeong, Sun-A;Hong, Deok-Gi
    • Therapeutic Science for Rehabilitation
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    • v.9 no.3
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    • pp.63-75
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    • 2020
  • Objective : The purpose of this study was to examine the changes in work performance and motor function of stroke patients in the Lee Silverman Voice Treatment-BIG (LSVT-BIG) program and to confirm its clinical applicability. Methods : Two stroke patients underwent the LSVT-BIG program for a total of 16 sessions (60 minutes per session and, four days a week for four weeks). To assess any changes between before and after the intervention, the Canadian Occupational Performance Measurement (COPM), Berg Balance Scale (BBS), Timed Up and Go (TUG), Functional Reaching Test (FRT), Manual Function Test (MFT) were used. Differences in scores between before and after the intervention were analyzed. Results : The performance and satisfaction of occupational performance increased after the intervention in both subjects. The performance time of the TUG decreased to 0.91, 8.42 seconds for each subject, increasing the walking speed. In FRT distance change, the subject increased in both the affected side and unaffected side. The BBS score increased by 3 points in one subject and by 6 points in the other, indicating improved balance. In addition, in the MFT score, subject A showed an improvement of 1 point on the unaffected side, and subject B showed an improvement of 1 point on the unaffected side and 3 points on the affected side. Conclusion : We confirmed the applicability of the LSVT-BIG program as a new intervention technique for stroke patients. Future, complementary research on the effects of the LSVT-BIG program on stroke patients will be needed.