• 한국물환경학회지
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• 제21권4호
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• pp.368-378
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• 2005

Inorganic matters originated from stone quarries and manufacturing plants could alter the ecological characteristics of adjacent aquatic systems, especially the structure and function of benthic macroinvertebrate community. In such situation, the locality of stone quarry and the quantity of inorganic matters would be important factors that determined the disturbing strength to the benthic macroinvertebrate community. Locality patterns of stone quarries were classified into 3 types in relation to the stream ecosystem; stream-proximity, upstream-inclusion and tributary-inclusion type. In the result of species:abundance analysis, stone quarry B (upstream-inclusion type) showed geometric distribution, while others showed broken-stick distribution pattern. The benthic macroinvertebrate communities closer to stone quarries showed smaller species numbers and standing crops among all types of stone quarries. However the values of species evenness index were not seriously different between controls and directly affected sites. These results indicated that the effect of inorganic disturbance would differ from those of organic pollution that induced the highly dominant state occupied by tolerant species. Number of occurred species, standing crops, community indices and biotic indices indicated that the community of upstream-inclusion type was the most seriously damaged from the inorganic disturbance, and the community would be very simple and unstable. Tributary-inclusion stone quarry heavily damaged to tributary system in biologically, but influence to the main stream seemed to be depended on the scale of main stream. Among 3 types of stone quarry localities, stream-proximity type induced the least damages to benthic macroinvertebrate community, though the degrees of damage were different along with distances between stream and stone quarry.

• 품질경영학회지
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• 제51권4호
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• pp.619-632
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• 2023

Purpose: The main function of INS (Inertial Navigation System) is to measure the position of an armed vehicle and its performance is confirmed through the positioning accuracy test of Korean Defense Standards (KDS). The current standards, however, do not provide clear test methods and the conditions for performing positioning accuracy tests. Accordingly, the purpose of this study is to develop a new method for positioning accuracy test which would be effective. Methods: In this study, a new INS positioning accuracy test method is suggested based on the analysis of test data collected through a statistical experiment known as central composite design. For the positioning accuracy experiment of K105A1, a self-propelled artillery, two factors of driving velocity and driving distance are considered. Results: Based on the analysis of experimental data, a regression model for the positioning error is fitted and the positioning accuracy test of INS is so developed to maximize the positioning error. The standard proximity rate is used as an additional test criterion to evaluate the performance level of INS. Conclusion: The proposed new positioning accuracy test for INS has the advantage of finding the nonconforming items effectively. It is also expected to be utilized for the other similar INS positioning accuracy tests.

• 교육시설
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• 제13권2호
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• pp.42-49
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• 2006

We have analysed the use and organization of space in the Centres des Documentations et de Informations(CDI) in lycees in France with the equivalent information centres. The majority of CDI are located in close proximity to the Academic staff and provide easy student access. The CDI provide not only books but also reviews, magazines and CD-Rom. This information is very important to pupils both in the pursuit of their higher studies and also with their future professional life as there is also careers information available to be discussed regularly with the careers advisor. The function of the CDI is not only to provide information. As part of the curriculum there are classes on how to access the information available in the CDI as well as Seminars and Audio-Visual courses. This management makes it possible for the CDI to operate, not only as a school library but also as a multi-function centre of documentation and information; a variety of spaces are also available: a room for private/small group study. A computer room (as well as a research corner), a reading room, monthly review room, photocopy room, rest room, exhibition room, careers information room, audio visual room etc. The results of this study can be used as essential information during the space planning of Korean school libraries in the future.

• 대한전자공학회논문지
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• 제27권2호
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• pp.31-38
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• 1990

외삽기법을 시용하여 실내의 소형 안테나 레이지에서 안테나 이득을 측정할 수 있는 시스템을 개발하였다. 외삽기법은 안테나의 절대이득 측정에 보통 사용되는 2-안테나 방법과 유사한데 가까운거리 구간에서 수신되는 신호의 크기를 거리의 함수로 연속적으로 측정한 후 외삽법을 사용한 신호처리로 무한거리에서 수신되는 신호의 크기를 계산함으로써 안테나의 원역장 이득을 구할 수 있다. 또한 원역장 이득과 근역보정인자를 결합하여 근역장 이득을 안테나로부터의 거리의 함수로 구하는 것도 가능하다. 이 외삽기법을 사용하여 측정한 표준이득 혼 안테나와 OEC 안테나의 이득 측정결과를 고찰하였다.

• 시스템엔지니어링학술지
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• 제16권2호
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• pp.47-58
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• 2020

Most of the reactor trips in Korean NPPs related to core protection systems were caused not because of proximity of boiling crisis and, consequently, a damage in the core, but due to particular miscalculations or component failures related to the core protection system. The most common core protection system applied in Korean NPPs is the Core Protection Calculator System (CPCS), which is installed in OPR1000 and APR1400 plants. It generates a trip signal to scram the reactor in case of low Departure from Nucleate Boiling Ratio (DNBR) or high Local Power Density (LPD). However, is a reactor trip necessary to protect the core? Or could a fast power reduction be enough to recover the DNBR/LPD without a scram? In order to analyze the online calculation of DNBR/LPD, and the use of fast power reduction as trip avoidance methodology, a concept of CPCS with fast power reduction function was developed in Matlab® Simulink using systems engineering approach. The system was validated with maximum of 0.2% deviation from the reference and the dynamic deviation was maximum of 12.65% for DNBR and 6.72% for LPD during a transient of 16,000 seconds.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제15권1호
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• pp.12-19
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• 2015

In order to guide the robots move along a collision-free path efficiently and reach the goal position quickly in the unknown multi-obstacle environment, this paper presented the navigation problem of a wheel mobile robot based on proximity sensors by fuzzy logic controller. Then a genetic algorithm was applied to optimize the membership function of input and output variables and the rule base of the fuzzy controller. Here the environment is unknown for the robot and contains various types of obstacles. The robot should detect the surrounding information by its own sensors only. For the special condition of path deadlock problem, a wall following method named angle compensation method was also developed here. The simulation results showed a good performance for navigation problem of mobile robots.

• 대한수학회보
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• 제53권6호
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• pp.1831-1844
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• 2016

In this paper, we improve the full-Newton step infeasible interior-point algorithm proposed by Mansouri et al. [6]. The algorithm takes only one full-Newton step in a major iteration. To perform this step, the algorithm adopts the largest logical value for the barrier update parameter ${\theta}$. This value is adapted with the value of proximity function ${\delta}$ related to (x, y, s) in current iteration of the algorithm. We derive a suitable interval to change the parameter ${\theta}$ from iteration to iteration. This leads to more flexibilities in the algorithm, compared to the situation that ${\theta}$ takes a default fixed value.

• 한국안전학회지
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• 제22권5호
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• pp.21-26
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• 2007

The computer program is developed to simulate the evacauation time for a building which is made geometrically complex. The program is intended for use both as a search and a design tool to analyze the evacuation safety through a wide range of structure environments. The computer program has a function of importing FDS's result to each individual resident in the building. These attributes include a walking speed reduction by producing visibility reduction for each person on the fire. $A^*$ pathfinding algorithm is adopted to calculate the simulation of escape movement, overtaking, route deviation, and adjustments to individual speeds due to the proximity of crowd members. Finally, a case study for a theater is presented to compared the calculated evacuation time with SIMULEX in detail. This program contribute to a computer program that evaluates the evacuation time of individual occupants as they walk towards, and through the exits especially for building, underground spaces like a subway or tunnel.

• Journal of Korean Neurosurgical Society
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• 제57권6호
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• pp.465-468
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• 2015

Hemangioblastomas in the pituitary stalk are especially rare. Most pituitary stalk hemangioblastomas reported in the literature were associated with von Hippel-Lindau (VHL) disease. Here, we report only the 3rd case of sporadic pituitary stalk hemangioblastoma diagnosed in a 60-year-old woman. Despite the danger of potential complications due to excessive vascularity or proximity to important neural structures, the tumor in our case was successfully removed while preserving pituitary function. In this case, complete surgical excision was shown to be an effective treatment option for symptomatic pituitary stalk hemangioblastoma, and we suggest careful evaluation of any highly enhancing mass with a signal void in the pituitary stalk preoperatively, even if no VHL disease is evident.

• 재활간호학회지
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• 제11권2호
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• pp.67-73
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• 2008

Purpose: The purpose of this study was to review and identify the meaning and components of the concept, Frailty. Method: We conducted literature review of studies that concluded the word of 'frail' or 'frailty between 1980 and 2008, and used MEDLINE, CINAHL database to select the articles. Results: Frailty is defined as a concept with multidomains, which are physical, cognitive, psychological, social. Critical characteristics of Frailty include multidominal deficiency, combined accumulation, diminished ability to keep up the independence of daily living, states beyond one's reserve capacity, dynamic relativity, proximity to adverse health outcome, aggregated symptoms. Frailty is caused by decreased physical activity, loss of sensory function, Chronic symptoms or signs, relationship with Caregiver, social isolation. Moreover, Frail elderly is at risk of falls and institutionalization. Conclusion: Frailty is very useful concept, because it has the potential to identify the elderly population at risk of adverse health outcomes. Based on this results, the appropriate tool for screening Korean Frail elderly and Nursing intervention for them needs to be developed.