• Journal of Environmental Impact Assessment
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• v.27 no.6
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• pp.635-646
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• 2018

This study sought to identify the characteristics of seasonal concentration differences of particulate matter influenced by land cover types associated with particulate matter emission and reductions, namely forest and urbanized regions. PM10 and PM2.5 was measured with quantitative concentration in 2016 on 23 urban air monitoring stations in Seoul, classified the stations into 3 groups based on the ratio of urbanized and forest land covers within a range of 3km around station, and analysed the differences in particulate matter concentration by season. The center values for the urbanized and forest land covers by group were 53.4% and 34.6% in Group A, 61.8% and 16.5% in Group B, and 76.3% and 6.7% in Group C. The group-specific concentration of PM10 and PM2.5 by season indicated that the concentration of Group A, with high ratio of forests, was the lowest in all seasons, and the concentration of Group C, with high ratio of urbanized regions, had the highest concentration from spring to autumn. These inter-group differences were statistically significant. The concentration of Group C was lower than Group B in the winter; however, the differences between Groups B to C in the winter were not statistically significant. Group A concentration compared to the high-concentration groups by season was lower by 8.5%, 11.2%, 8.0%, 6.8% for PM10 in the order of spring, summer, autumn and winter, and 3.5%, 10.0%, 4.1% and 3.3% for PM2.5. The inter-group concentration differences for both PM10 and PM2.5 were the highest in the summer and grew smaller in the winter, this was thought to be because the forests' ability to reduce particulate matter emissions was the most pronounced during the summer and the least pronounced during the winter. The influence of urbanized areas on particulate matter concentration was lower compared to the influence of forests. This study provided evidence that the particulate matter concentration was lower for regions with higher ratios of forests, and subsequent studies are required to identify the role of green space to manage particulate matter concentration in cities.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.05a
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• pp.178-183
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• 1997

차세대 원전 경보시스템에서의 경보처리는 발전소의 과도상태 및 비정상운전시 경보필터링, 경보억제, 발전소 상태에 근거한 우선순위처리 등을 적용하여 운전원에게 경보정보를 효율적으로 처리하고자 한다. 경보표시 측면에서는 인간공학 및 인지공학적 요소를 적용하여 운전원의 인적오류를 최소화하여 기존 경보계통의 단점을 개선하고자 하였다. 본 논문에서는 차세대 경보계통설계의 구현을 위해서 COAST(Computerized Alarm System Toolbox)를 사용하여 경보처리방법 중 그룹핑기법을 구현하였다.

• 정보보호뉴스
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• no.9 s.132
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• pp.22-24
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• 2008

개인정보보호에 대한 관심과 사회적 이슈는 국내뿐만이 아니라, 전 세계적인 공동의 관심사로 떠오른지 오래다. 국제기구가 프라이버시 보호 법안을 제정해 각국 정부에 권고하는 한편, 개인정보보호, 프라이버시 보호와 비즈니스의 연관관계를 분석하는 시도가 늘어나고 있다. 국제적인 컨설팅 그룹 딜로이트에서 보안 프라이버시와 데이터 보호 분야를 맡고 있는 Ken DeJarnette에게 비즈니스와 개인정보 및 프라이버시 보호의 연관성에 대해 다양한 조언을 요청했다.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05a
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• pp.239-245
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• 1998

GOMS 평가는 운전원 개인의 인지과정에 초점을 두어 직무 절차의 학습시간과 직무 실행시간을 예측하고 직무 실행시 요구되는 인지부하를 분석한다. 하지만 실제 원전의 운전은 그룹에 의해 이루어지므로 운전원간 의사소통과 직무의 상호 의존관계를 고려하여 기존의 GOMS를 확장한 분산형 GOMS를 고안하였다. 본 논문에서는 분산형 GOMS 평가기법을 CE형 원전의 비상운전절차서에 시험적으로 적용해 본 결과를 제시한다.

• JOURNAL OF ELECTRICAL WORLD
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• s.452
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• pp.89-93
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• 2014

지난 6월 5일 러시아 모스크바에서 개최된 국제표준화기구(ISO) 기술위원회(TC)85 총회에서 한국원자력안전기술원 김창범 박사가 3년 임기의 워킹그룹22 컨비너로 선임됐다는 낭보가 전해졌다. 원자력 및 방사선 관련 국제표준을 제정하는 ISO TC85에서 아시아 및 아프리카인으로는 최초로 일본, 인도, 중국, 호주 등을 제치고 한국이 의장국을 수임하는 쾌거를 올린 것이다. 이는 한국의 원자력 및 방사선 관련 기술력이 국제적으로 인정받았음을 보여주는 분명한 사례라는 평가다. 따라서 이번 컨비너 선임으로 향후 원자력 및 방사선 관련 국제표준 분야에서 우리나라의 역할과 위상은 더욱 활발하고 높아질 전망이다. 아시아 최초의 ISO TC85 컨비너인 한국원자력안전기술원 김창범 박사를 만나 그간의 활약상과 향후 행보에 대해 자세히 들어봤다.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.11a
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• pp.215-216
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• 2009

본 논문에서는 그리드 환경에서 대규모의 분산 데이터 분석 환경을 제공하고자 한다. 기존의 접근방식으로서 자원 성능 기반의 사전 예약 기법인 Push 기법과 가용자원이 능동적으로 작업을 가져오는 Pull 방식을 조합하여 분산 효율과 실행 시간을 최소화 하는 기법을 제안하고자 한다.

• Sleep Medicine and Psychophysiology
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• v.24 no.1
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• pp.24-31
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• 2017

Objectives: Periodic limb movement disorder (PLMD) has been debated with regard to its clinical significance and diagnostic criteria. The current diagnostic criterion for PLMD in adults has been changed from periodic limb movement index (PLMI) > 5/hour to PLMI > 15/hour by the International Classification of Sleep Disorders (ICSD). In this study, we aimed to investigate the changes in polysomnographic sleep variables according to PLMI and to determine the relevance of the diagnostic criterion for PLMD. Methods: Out of 4195 subjects who underwent standard polysomnography, we selected 666 subjects (370 males and 296 females, aged $47.1{\pm}14.8$) who were older than 17 years and were not diagnosed with primary insomnia, sleep apnea, narcolepsy, or REM sleep behavior disorder. Subjects were divided into three groups according to PLMI severity: group 1 ($PLMI{\leq}5$), group 2 (5 < $PLMI{\leq}15$), and group 3 (PLMI > 15). Demographic and polysomnographic sleep variables and Epworth sleepiness scale (ESS) were compared among the three groups. Results: There were significant differences among the three groups in age and gender. Sleep efficiency (SE) and stage 3 sleep percentage in group 1 were significantly higher than those in groups 2 and 3. The wake after sleep onset (WASO) score in group 1 was significantly lower than those in groups 2 and 3. However, there were no significant differences in SE, stage 3 sleep percentage, or WASO between groups 2 and 3. Sleep latency (SL) in group 1 was significantly lower than that in group 3, but there was no difference in SL between group 2 and group 3. ESS score in group 1 was significantly higher than that in group 3, but there was no difference between group 2 and group 3. Partial correlation analysis adjusted by age showed that PLMI was significantly related to SE and WASO. Conclusion: This study suggests that PLMI influences polysomnographic sleep variables. In addition, we found the individuals who did not have PLMD but had PLMI > 5 were not different in polysomnographic sleep variables from the individuals who had PLMD according to the current criterion. These results raise questions about the relevance of the current diagnostic criterion of PLMD.

• Journal of KIISE:Information Networking
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• v.30 no.3
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• pp.329-342
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• 2003

Most of the existing multicast routing protocols for ad-hoc networks do not take into account the efficiency of the protocol for the cases when there are large number of sources in the multicast group, resulting in either large overhead or poor data delivery ratio when the number of sources is large. In this paper, we propose a multicast routing protocol for ad-hoc networks, which particularly considers the scalability of the protocol in terms of the number of sources in the multicast groups. The proposed protocol designates a set of sources as the core sources. Each core source is a root of each tree that reaches all the destinations of the multicast group. The union of these trees constitutes the data delivery mesh, and each of the non-core sources finds the nearest core source in order to delegate its data delivery. For the efficient operation of the proposed protocol, it is important to have an appropriate number of core sources. Having too many of the core sources incurs excessive control and data packet overhead, whereas having too little of them results in a vulnerable and overloaded data delivery mesh. The data delivery mesh is optimally reconfigured through the periodic control message flooding from the core sources, whereas the connectivity of the mesh is maintained by a persistent local mesh recovery mechanism. The simulation results show that the proposed protocol achieves an efficient multicast communication with high data delivery ratio and low communication overhead compared with the other existing multicast routing protocols when there are multiple sources in the multicast group.

• Korean Security Journal
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• no.20
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• pp.71-93
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• 2009

The purpose of this study was to evaluate the effects of using spinal stabilization exercise for the improvement of atrophy of the multifidus and psoas major, of pain and disability with chronic low back pain in private guard and security. For 42 patients diagnosed with CLBP, and divided into spinal stabilization exercise group(SSEG) and general spinal strengthening exercise group(GSSEG). Each exercise was conducted for 10 weeks. Pain and disability were measured before and after exercise using the Visual analogue scale(VAS) and the Oswestry disability index(ODI). Cross section area(CSA) of both the left and right multifidus and the psoas major at the upper end plate of L4 were measured before and after exercise using computed tomography(CT). After 10 weeks of exercise, the both group's pain and lumbar disability were significantly decreased(p<0.01). Also there was significant difference in both group(p<0.05). In addition, the CSA of the left and right multifidus and posas major were significantly increased as compared to the pre-exercise in both group(p<0.01). But SSEG's cross sectional areas of multifidus was more significantly increase than GSSEG(p<0.05). In summary, Spinal stabilization exercise is more effective in improving atrophy in private guard and security patients, in reducing patients' pain and disability. It is an effective treatment to aid rehabilitation in these cases.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.4
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• pp.282-285
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• 2019

A 100-nm gate-length metamorphic high electron mobility transistor(mHEMT) with a T-shaped gate was fabricated using a two-step gate recess and characterized for DC and microwave performance. The mHEMT device exhibited DC output characteristics having drain current($I_{dss}$), an extrinsic transconductance($g_m$) of 1,090 mS/mm and a threshold voltage($V_{th}$) of -0.65 V. The $f_T$ and $f_{max}$ obtained for the 100-nm mHEMT device were 190 and 260 GHz, respectively. The developed mHEMT will be applied in fabricating W-band monolithic microwave integrated circuits(MMICs).