• 대한전기학회논문지:시스템및제어부문D
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• 제53권7호
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• pp.483-490
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• 2004

The descriptor system model has a high ability in representing dynamical systems. It can preserve physical parameters in the coefficient matrices, and describe the dynamic part, static part, and even the improper part of the system in the same form. The design of mixed $H_{2}/H_{\infty}$ controllers for linear time-invariant descriptor systems is considered in this paper. Firstly, an $H_2$ and $H_{\infty}$ synthesis problems fur a descriptor system are presented separately in terms of linear matrix inequalities (LMIs) based on the bounded real lemma. Then, we show that the existence of a mixed $H_2/H_{\infty}$ controller by which the $H_2$ norm of the second channel is minimized while keeping the $H_2$ norm bound of the first channel less than ${\gamma}$, is reduced to the linear objective minimization problem. The class of desired controllers that are assumed to have the same structure as the plant is parameterized by using the linearizing change of variables.

• 정신신체의학
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• 제5권1호
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• pp.129-134
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• 1997

The meddle years start when persons achieve maturity and end when they realize they are old, and we commonly call ages between thirty-live and sixty five the middle years. Thinking of life as a play, the middle years lead up to and away from the climax of the plot. In the early part of middle age, the man is the main support of his family, and is out to establish himself in his career. He is in a race toward success, and may acquire a sponsor who picks him out as a protege. In the middle part of middle age, the man is ready to come into his own and may break with his sponsor. Most persons are now at the height of their potential, know their areas of competence, and have the satisfaction of feeling in control in them. They need no longer prove themselves from day to day, for they are credited with past accomplishments. Some are caught in "promotion or success depression", and some continue to change jobs creating difficulties is readjustment. The more satisfactory changes usually occur within a career rather than through shifiting careers. In e later part of the middle age the man worries about his physical health, and experiences depression in facing the retirement. Woman frequently change the course of their lives some time between the ages of thirty-five and forty, and may resume their education or careers. Tee quarters of women are passing through "involutional melancholia".

• 지역사회간호학회지
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• 제18권4호
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• pp.634-642
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• 2007

Purpose: To investigate subjective symptoms of musculoskeletal disorders in women workers Method: From February to April, 2006, 292 women workers working in 16 companies were surveyed using KOSHA CODE (H-30-2003). Result: Of the workers, 84.0% had at least one musculoskeletal disorder. The mean score of the severity of musculoskeletal disorder symptoms was 7.41 out of 25. As for the prevalence rate by body part, shoulder was the most common and severe body part of musculoskeletal disorders, and significant differences were shown in neck, shoulder, and lower limb according to the type of working. The severity of married workers was significantly higher than that of unmarried ones. Significant difference was shown in the severity of disorders by the type of working and in body parts according to the type of working. Conclusion: The self-reported symptoms of musculoskeletal disorders were very frequent in women workers, but the severity of the symptoms was relatively low, suggesting the early symptoms of disorders. Specifically, given the highly frequent self-reported symptoms in the shoulder part found in married women workers, intensive prevention is recommended. Furthermore, an ergonomic aspect should be concerned to consider physical characteristics of women workers.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 봄 학술논문 발표대회
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• pp.87-88
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• 2022

For an earthquake-safe urban environment, the Republic of Korea conducts seismic performance evaluation in accordance with laws and guidelines to assign safety ratings and implement necessary management measures such as repairs and reinforcements. In the seismic performance evaluation result, structures lacking in preparation for earthquakes are prioritized and classified into measures such as repair, reinforcement, or careful observation to respond to physical risks such as earthquakes. Such repair and reinforcement work is not a one-time thing, but it is necessary to further enhance the effect through continuous follow-up observation. In this study, the location of the vertical and horizontal displacement measuring part of the construction part is displayed so that the post-construction status of the reinforcement construction part can be visually checked by identifying the problems in the process of post-monitoring in 2022 for the maintenance and reinforcement work of local governments' public facilities carried out in 2021. We propose a plan to institutionalize the installation of, inspection tools, and crack gauges at certain locations in the construction department, and to have facility managers periodically inspect and manage them with a smartphone program or the 'Facility Autonomous Safety Inspection' app.

• 한국항공우주학회지
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• 제35권1호
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• pp.10-17
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• 2007

Part 1에서 수행된 검정금파리의 “8자 운동”에 대한 해석결과는 와류들이 양력과 추력발생에 중요한 역할을 하는 것으로 나타났다. 곤충날개에서 발생되는 공기역학적 힘은 레이놀즈수와 같은 공기역학적 요소와 더불어 진동수, 운동진폭, 운동성분 등과 같은 운동학적적 요소들 또 날개의 형태 및 개수등과 같은 형태학적 요소들에 따를 것으로 생각된다. 본 연구에서는 레이놀즈수, 진동수 그리고 운동성분에 따른 양력과 추력발생을 고찰함으로써 이들이 공기역학적으로 어떤 영향을 미치는가를 조사하였다. 이로써 part 1의 결과를 물리적으로 좀 더 상세하게 설명할 수 있는 근거를 찾고자 하였다. 해석결과 “8자 운동”을 구성하는 운동성분 중 회전운동이 추력발생에 지배적인 역할을 하고 있었으며, 또한 추력발생은 반시계 방향의 회전순환과 깊은 관련이 있었다.

• 공업화학
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• 제18권5호
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• pp.407-414
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• 2007

Moldflow사의 CAE 해석 프로그램인 MPI (Moldflow Plastics Insight)를 이용하여 PP(polypropylene)에 talc 20%가 들어간 수지를 사용한 자동차 공기 청정기 상부 덮개의 최적 공정을 찾았다. 핀 게이트가 하나인 기존 시스템을 CASE-1, 두 개로 새로운 공정을 CASE-2로 디자인하여 두 공정에 대한 유동 발란스 등을 비교하였다. CASE-2는 충진 시간이 더 짧아 생산성과 공정성의 향상이, 유동성과 부피수축율이 하부 덮개와 유사하게 나타나 조립성과 조립 후의 변형 및 물성발현이 향상되었다. 또한 전단속도와 전단응력의 해석결과, CASE-1의 문제점은 잔류 응력에 의한 것보다는 상 하부 덮개의 크기 차이에 의한 것으로 판단되며, 결국 수지의 배향 문제는 게이트 구조를 최적화 함으로써 파손 문제를 해결할 수 있을 것이라 예상된다.

• International Journal of Human Ecology
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• 제13권2호
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• pp.53-67
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• 2012

This study uses the 1999-2009 Korean Time Use Survey to explore how mothers' employment affects parental time spent in activities that may relate to their children's weight. Specifically, it estimates two-part regression models to assess the effects of maternal employment upon the amount of time mothers spend in activities potentially related to their preschool children's eating and physical activity. The findings suggest that working mothers and those mothers who work longer hours allocate significantly less time in food preparation, eating with the child, and supervising the child's physical activity than mothers who are not employed and those who work fewer hours. The paper also finds that spouses of working mothers do not allocate more time to these activities to offset the reduction in mothers' time. Also, using local unemployment rates as instrumental variables, maternal employment is found to allow mothers to spend significantly more time on food preparation and family meals, although its effect on mothers' total childcare time is negative. Several aspects of Korean society may have made the relationship between maternal employment and childhood weight issues different from what was found in other countries.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권3호
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• pp.1057-1073
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• 2015

In this paper, we consider cooperative D2D communications in cellular networks. More precisely, a cellular user leases part of its spectrum to facilitate the D2D communication with a goal of improving the energy efficiency of a D2D pair. However the D2D pair is untrusted to the cellular user, such resource sharing may result in the information of this cellular user unsecured. In order to motivate the cellular user's generosity, this D2D pair needs to help the cellular user maintain a target secrecy rate. To address this issue, we formulate a joint spectrum and power allocation problem to maximize the energy efficiency of the D2D communication while guaranteeing the physical layer security of the cellular user. Then, a theorem is proved to indicate the best resource allocation strategy, and accordingly, an algorithm is proposed to find the best solution to this resource allocation problem. Numerical results are finally presented to verify the validity and effectiveness of the proposed algorithm.

• 한국환경과학회지
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• 제14권9호
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• pp.835-842
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• 2005

The three-dimensional eco-hydrodynamic model was applied to estimate the physical process in terms of COD (chemical oxygen demand) and net supply(or decomposition) rate of COD in Kamak Bay to find proper management plan for oxygen demanding organic matters. The estimation results of the physical process in terms of COD showed that transportation of COD is dominant in surface level while accumulation of COD is dominant in bottom level. In the case of surface level, the net supply rate of COD was 0 -0.50 mg/m2/day. The net decomposition rate of COD was 0 -0.04 mg/m2/day in middle level(3 -6m) and 0.05 -0.1 5 mg/m2/day in bottom level(6m -bottom). These results indicates that the biological decomposition and physical accumulation of COD are occurred predominantly at the northern part of bottom level. Therefore, it is important to consider both allochthonous and autochthonous oxygen demanding organic matters in the region.

• 대한정형도수물리치료학회지
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• 제21권2호
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• pp.25-31
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• 2015

Background: A chronic condition that has a fine rupture and inflammation that occurs in the plantar fascia medial calcaneal origin or occur during the rough part is called plantar fasciitis heel pain plantar fasciitis. Using functional taping to fix the subtalar joint were investigated through an experiment for how much the elastic taping effect than applying it to correct by applying the inelastic taping. This study was performed to change the balance and walking ability shown by the groups that do not apply to the application of the functional group taping. Methods: 20 people functional taping group 10 patients, deep friction massage was applied to the group to 10 people. The duration of the experiment were divided into groups going deep friction massage and the month after you apply before applying the functional taping. Results: Analysis showed statistically significant improvement in all time in both groups. All functional taping group and deep friction massage group had no significant difference with respect to balance and walking ability. Conclusion: When you saw the results of this study showed functional taping group is plantar fasciitis is the patients for treatment to mark fasciitis patients than those applying deep friction massage effects that increase is believed to help the symptoms of recovery.