• Journal of Korea Soil Environment Society
• /
• v.2 no.1
• /
• pp.51-61
• /
• 1997

The objective of this study is to evaluate the feasibility of Pumping-and-Treatment system (PTS) for remediation of the saturated zones contaminated with NAPLs. A simulation is carried out for the removal of DNAPLs (denser-than-water non-aqueous phase liquids) and LNAPLS (lighter-than-water non-aqueous phase liquids) distributing at and below the water table. In the study, LNAPL and DNAPL are assumed to be n-hexane and 1,1-dichloroacetone, respectively. The model system studied consists of four heterogeneous soil layers with different permeabilities. Groundwater flows through the bottom layer and a pumping well is located under the initial water table. The time-driven deformation of the water table and removal efficiency of contaminants are estimated after vacuum application to the inlet of the well. In the calculation, FVM (Finite Volumetric Method) with SIMPLEC algorithm is applied. Results show that removal efficiencies of both DNAPL and LNAPL are negligible for the first 5 days after the PTS operation. However, when the cone-shape water table is formed around the inlet of the pumping well, the rapid removal rate is obtained since NAPLs migrate rapidly through the curvature of the water table. The removal efficiency of DNAPL is estimated to be higher than that of LNAPL due to the gravity. The results also show that the fluctuation or cone-shaped depression of the water table enhances the removal efficiency of NAPLs in saturated zones. The simulation results could provide a basis of the PTS design for the removal of NAPLs in saturated zones.

• Fashion & Textile Research Journal
• /
• v.1 no.2
• /
• pp.173-181
• /
• 1999

The purpose of this study was to investigate actual sleeping environments in Ondol rooms depending on the season. The experiment was performed on five healthy women. The bedroom environments using Ondol were measured in five cases (three apartments and two houses). The environments in bedroom, bedding temperature, skin temperature and thermal sensation were measured continuously through the seven days for each season in real life. This data of sleeping environments were analyzed in the view of seasonal variations and housing types. Annual average bedroom temperatures: $26.2{\sim}31.0^{\circ}C$ in apartments, $15.7{\sim}33.6^{\circ}C$ in houses. Annual average bedroom humidity: 48.3~82.1% RH in apartments, 64.9~87.0% RH in houses. During sleeping, temperatures of contact surfaces like sheets and under quilts ranged between $30.5^{\circ}C$ and $34.1^{\circ}C$ regardless of season or housing type. Annual average rectal temperature was $36.8^{\circ}C$ with no significant difference in season or housing type. In the point of thermal sensation, neutral temperature of the bedroom was $25.9^{\circ}C$ in apartments and $20.3^{\circ}C$ in houses. It was concluded that in spite of thermal environmental variations according to the seasons, skin, bedding and bedroom temperatures in apartments were better and more stable than those of houses. It is regarded that while houses are brick structured, apartments are steel-frame structured. Due to better insulation and air tightness, apartments were affected less from outdoor temperature and maintained higher room temperature than houses.

• KIISE Transactions on Computing Practices
• /
• v.23 no.7
• /
• pp.434-439
• /
• 2017

More and more people are suffering from sleep disturbance, which can have many different causes. The healthcare industry, which can help people with this disability, is one technology that is currently in the spotlight. However, current services are vulnerable to data concentration, because they are simple telemedicine services that transmit all data to a remote server and process the data on the server. They have a disadvantage in that the data cannot be streamed in real time by synchronizing the biometric data of remotely protected persons. In order to solve this problem, we propose a service structure for streaming biometric data of protected persons to a hospital or guardian in real time, using a self-organizing distributed middleware platform without a central server. We prove that it is possible to provide an effective streaming service by evaluating the service start time and average delay time.

• Sleep Medicine and Psychophysiology
• /
• v.1 no.2
• /
• pp.172-181
• /
• 1994

Obstructive sleep apnea syndrome(OSAS) is most frequently diagnosed in the sleep laboratories and its severity is objectively estimated. In terms of treatment, the most prevalent method is the continuous positive airway pressure(CPAP) application as of now. However, in Korea, CPAP is still not sufficiently known and it is attributable to the fact that sleep study facilities have not been popularized. In this article, the authors present their own experience with CPAP in nine subjects with OSAS. In this study, CPAP was found to decrease stage 1 sleep and to increase stage 2 sleep, with increasing mean oxygen saturation and decreasing lowest oxygen saturation during nocturnal sleep. Also, it tended to increase sleep continuity and generally to improve sleep architecture. Rebound slow wave and/or REM sleep stages during CPAP were also noted in 8 out of 9 cases. The authors suggest that CPAP should be considered as the primary mode of treatment for patients with obstructive sleep apnea syndrome and related educational programs for physicians should be developed and provided by sleep specialists.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2004.02a
• /
• pp.223-245
• /
• 2004

최근, 자유수면을 갖는 비압축성 유체의 해석을 위해 Hirt and Nichols(1981)가 제안한 VOF법이 자유수면을 취급하는 많은 학문분야에서 활발히 활용되고 있다. 특히, 일본에서 잠제에 의한 쇄파해석에 암전 등(1994)이 처음으로 VOF법을 적용한 이래 많은 연구자에 의한 공동연구의 결과로 개발된 CADMAS-SURF(해안개발기술연구 Center, 2001)는 사용자가 직접 입·출력을 제어할 수 있는 효과적인 2차원파동장의 해석프로그램으로 알려져 있다. 국내에서는 김 등(2001, 2002)이 최초로 VOF-SOLA법을 이용한 수치파동수로를 제안하고 잠제주변의 파동장해석을 수행하고 있다. (중략)

• The Journal of Korean society of community based occupational therapy
• /
• v.9 no.1
• /
• pp.15-24
• /
• 2019

Objective : The purpose of this study is to investigate the relationship between the leisure experience, leisure identity, depression, and self-respect of the elderly with sleep disorders through leisure activities. Methods : The elderly with sleep disorders were applied for more than 4 weeks from March to July, 2018. Depression, self-respect, and sleep quality before and after the application of leisure activities were analyzed by the corresponding sample t test. The leisure experience, leisure identity, and change in leisure activities were analyzed by SEM(structural wearing model analysis through confirmatory factor analysis. Results : The results of this study are as follows. First, there was a significant difference in depression level before and after leisure activities (p = .000). Second, there was no significant difference in self-respect before and after leisure activities (p = .182). Third, there was a significant difference in the quality of sleep before and after leisure activities (p = .000). Fourth, the effects of leisure experience, leisure identity, and change on leisure activities showed that leisure experience influenced leisure identity and change. However, leisure identity affected depression and sleep quality among the factors of change. Conclusion : A decrease in the quality of sleep that can occur in the elderly can affect the quality of life. It was found through experiments that the leisure activities of elderly people with sleep disorder can bring about positive changes in depression level and sleep quality of the elderly.

• Sleep Medicine and Psychophysiology
• /
• v.6 no.2
• /
• pp.116-125
• /
• 1999

Objectives: The purpose of this study is to investigate the effect of exercise load on sleep structure and stress hormone secretion during sleep. Methods: Five male physical education students were included in this study after giving their written, informed consents in the Research Institute for Sports Science at the University of Hanyang. All subjects have performed for at least 3 years in a regular aerobic exercises such as football, basketball, and running. The subjects were divided into three groups ; NOE(non-exercise), MDE(middle duration exercise), LDE(long duration excercise). MDE group maintained a total of 120 min exercise, and LDE group maintained a total of 300 min exercise by football, basketball or badminton. All subjects were acclimatized to the experimental sleep condition by spending one night under expermental conditions, including the placement of an intravenous catheter. During the subsequent night(24:00-08:00), somnopolygraphic sleep recordings were obtained, and blood for measuring growth hormone, cortisol, testosterone, and $\beta$-endorphin was collected every 120 min throughout the night. Blood samples were obtained from prominent forearm veins of subjects. Then, the samples were immediately placed in ice and centrifuged within 10 min at 3000 rpm at $4^{\circ}C$. Statistical analyses were performed using the SPSS/$PC^+$. Data were analyzed by one-way ANOVA with repeated measures. Results: No significant differences among groups were observed in sleep latency, total sleep time, stage 2 sleep, and slow wave sleep. However, daytime exercise produced significant changes in stage 1 sleep, REM sleep, stage 2 sleep latency, REM sleep latency and sleep efficiency. Stage 1 sleep, stage 2 sleep latency, and REM sleep latency significantly increased in LDE compared to those of NOE and MDE groups. But the amount of REM sleep significantly decreased in LDE. Sleep efficiency of MDE was higher than those of NOE and LDE. The blood concentrations of growth hormone, testosterone, and cortisol during night sleep were significantly lower in LDE than in NOE. $\beta$-endorphin concentrations in blood during night sleep were not different among groups. Conclusion: The daytime exercise load was significantly related to sleep structure and stress hormone secretion during night sleep. Long duration exercise showed a harmful effect on sleep structure and hormone secretion. However, middle duration exercise had a beneficial effect on sleep structure and hormone secretion during sleep.

• The Korean Journal of Petroleum Geology
• /
• v.5 no.1_2 s.6
• /
• pp.1-8
• /
• 1997

Seismic stratigraphic analysis of the high resolution profiles obtained from the southeastern shelf of Korea divided the deposits into 4 sequences; 1) sequence D, 2) sequence C, 3) sequence B and 4) sequence A (Holocene sediments). Sequence D was deposited in shallow-water environment at west of the Yangsan Fault as the basin subsided. On the other hand, the eastern part was formed at the slope front. Landward part of the slope-front fill sediments were eroded and redeposited nearby slope due to the syndepositional tilting of the basin. This tilting probably resulted from the continuous closing of the Ulleung Basin. Sequence C is made of stacked successions of the lowstand fluvial sediments, transgressive sediments and marine highstand sediments derived from the paleo-river in the western part of the Yangsan Fault. Sequence C in the eastern part of the Yanshan Fault was formed at the shelf break. Progradation of the lowstand sediments resulted in broadening of the shelf. Sequence C in the eastern part was also tilted but the tilting was weaker than in Sequence D. During the formation of sequence B the tilting stopped and the point source instead of the line source started in both sides of the Yangsan Fault. Sequence B was composed of the highstand systems tract partially preserved around the Yokji island, lowstand systems tract mainly preserved in the Korea Trough and transgressive systems tract. After the stop of the tilting, the force of compression due to the closing of the Ulleung Basin may be released by the strike-slip faults instead of tilting.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2007.12a
• /
• pp.170-172
• /
• 2007

미포만 공유수면 매립공사는 방파호안 854.5m를 축조하고 부지 $100,514.3m^{2}$를 매립하여 현대중공업(주)의 조선용 블록 제작장 및 적치장을 조성하는 사업이다. 2004년 2월 해양 수산부 설계자문을 실시하고, 2004년 5월 실시계획 인가를 득하여 사업을 추진하여 오던 중, 최근의 이상파랑 및 태풍 내습 (2005년 8월, 태풍 나비)등으로 인하여 피해가 발행하는 동 사업시행자인 현대중공업(주)에서 사업계획의 일부 변경(공구분할)올 요청하여 1공구(미포만 북방파제 보강)공사만을 2005년 8월말로 완료하였다. 미포만 공유수면(II-Block) 매립공사(2공사)는 파량 내습시 피해발생 사전예방 및 상향된 심해설계파 등에 안전한 구조물 축조로 배후매립부지의 안전성을 확보할 수 있도록 호안의 마루높이를 상향하고 케이슨 및 피복재 중량을 증대하여 설계 및 시공할 수 있도록 하였다.

• Asian Journal of Turfgrass Science
• /
• v.16 no.2
• /
• pp.107-114
• /
• 2002

In this study, We measured air temperature in a vegetated area to investigate if stand types and height affect air temperature. With the measured data, we analyzed the relation-ships between air temperature vs. ground cover type, vegetated area, stand structure, stand density, and tree volume by regression analysis. The results show that the paved area and open field have higher air temperatures than the vegetated area and water-related areas. Among the stand types, the stand with overstory and sub-overstory showed relatively low are temperature. The stand with overstory had lower air temperature than the stand with sub-overstory. Increasing stand density was effective for lowering air temperature.