• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.765-766
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• 2015

We present a color-magnitude (CM) diagram of M35, an open cluster. A DSLR camera was used for measuring the color index with the RGB channels. It is cost-effective and has relatively easy controls compared to astronomical CCDs for educational environments. The 8-inch refracting telescope was used at the Korea Science Academy of KAIST in Busan. The B-G color index was obtained from observations and the magnitudes from publications in order to draw CM diagram. The linear correlation of B-G to B-V is found. The RGB channel of the DSLR camera can be easily represented on the CM diagram for astronomical education with aid of easy controls.

• Journal of Construction Engineering and Project Management
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• v.7 no.4
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• pp.20-28
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• 2017

In almost every construction project, delay is an inevitable yet controllable phenomenon. The Indian construction industry encounters an enormous amount of delays in projects. Delay affects both time and money in the forms of schedule and cost overruns, respectively. Due to impressive and dynamic growth in the Indian construction sector, planned efforts are essential to limit these undesirable delays. On account of the surge in the rate of residential building construction, the task of identification and analysis of the delays in residential projects in India has been attempted by the authors. A questionnaire survey was conducted involving 100 stakeholders. Further analysis included an Importance Index to rank the identified delays, Principle Component Analysis for advanced statistical analysis, and Correlation Analysis to check the extent of agreement amongst stakeholders. Conclusions drawn with reference to the analysed data eventually reflected finance-related issues, as well as labour related problems as the dominating causes of delays. The aim of the research is to provide insight to the construction stakeholders and researchers, on an international scale, with the obtained results.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10b
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• pp.223-225
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• 2003

분산 데이터베이스 시스템 환경에서는 특정 노드로 집중되는 부하의 분산이나 가용성 및 안정성 제공을 위해 데이터 분할기법 (fragmentation)과 복제기법(replication)을 사용한다. 이때 전송된 데이터에 대한 기존의 색인 재활용 기법과 벌크 로딩(bulk loading) 기법은 효율적인 색인 구성을 위해 논리적인 페이지 포인터를 물리적 주소로 변환하는 물리적 사상구조를 필요로 하거나, 색인 구성시간과 검색성능 모두를 향상시키지 못하는 문제점을 지닌다. 본 논문에서는 이와 같은 문제점을 해결하기 위해 색인 전송기법을 제안한다. 본 기법은 색인 재활용을 위해 물리적 사상구조를 추가로 유지하거나, 검색 성능을 향상시키기 위해 전체 데이터 집합을 정렬하는 것이 아니라, 데이터가 전송될 사이트에 색인구조물 저장하기 위한 물리적 공간은 예약하고 예약된 공간에 색인구조를 전송, 기록함으로써 색인 구성비용을 줄이게 된다. 또한 예약된 공간을 연속적인 페이지구조로 구성함으로써 색인 구성 시 자식노드에 대한 위치정보를 예상하여 부모노드가 지니는 자식노드에 대한 위치정보 기록 비용을 줄일 수 있다.

• Journal of the Korean Society of Safety
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• v.8 no.2
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• pp.58-63
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• 1993

Recently, a large amount of flammable or explosive materials have been handled or stored in chemical industries. H the equipments fail or the materials release in consequence of operation errors, fire and explosion could occur to them. Thus, risk assessment using quantification of risks is very important when design of processes and modifications of installed processes are performed. The purpose of this study is to develop the program for fire and explosion index in order to quantify the expected damage of fire and explosion incidents in chemical plants, to identify equipment that would be likely to contribute to the creation or escalation of an incident, to comunicate the potential fire and explosion risk to management and to account of damage cost.

• Proceedings of the Optical Society of Korea Conference
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• 2003.07a
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• pp.14-15
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• 2003

Polymer optical fibers (POFs) are being considered as important high-speed communication media in the area of local area networks, datalinks and optical sensors. Large core diameter (500～1000 $\mu$m) and large numerical aperture (0.2~0.9) in a POF allow easy processing and connectorization, low cost high efficiency of beam coupling from LDs or LEDs, and complete immunity to EMI／EMR. There are many reports about 2.5 Gbps transmission the polymethylmethacrylate (PMMA) graded index (GI) POF over a distance of 100 m. (omitted)

• Transactions of the Korean hydrogen and new energy society
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• v.30 no.1
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• pp.58-66
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• 2019

Static compound parabolic collectors (CPCs) have advantages such as ease for fabrication and lower cost compared with other concentrating collectors. In this study, thermal performance analysis of CPC employing heat storage tank was carried out. The clearness index and capacity of heat storage tank are taken as the main parameters for numerical simulation. The effects of the parameters on the hourly and daily system performances ncluding the useful energy, heat loss, and collector efficiency were numerically investigated. Results showed that the system has a potential for efficient recovery of solar thermal energy.

• Korean journal of food and cookery science
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• v.19 no.3
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• pp.286-294
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• 2003

The purpose of this study was to analyze the food service management practices and productivity in 49 elementary schools in the Daegu and Gyeongsangbuk-do areas. Survey questionnaires were used to obtain a variety of quantitative and qualitative information, including general food service management and productivity, on elementary school food service systems. Descriptive analysis, $\div$2-test, t-test and one-way ANOVA analysis were used as the statistical methods in this study. Eighteen elementary schools were located in urban areas, 13 in provincial areas and 18 in isolated areas. The average number of meals was 565.1, with a significant difference (p＝0.001) between the areas. The average cost per a meal was 1151.0 Won, with a significant difference (p＝0.001) between the areas. The productivity Index (meal/hour) was 13.5, with a significant difference (p＝0.001) between the areas. There was a significant positive correlation of the productivity Index between the total number of meal, the number of employees, the total food cost, meals per employee and the employee's working period. There was a significant negative correlation between the productivity Index and the number of side dishes, the lost per meal, the labor cost per meal and the employee's job satisfaction degree index (JDI).

• Physical Therapy Korea
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• v.20 no.1
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• pp.18-27
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• 2013

The purpose of this study was to compare the ring lock type knee-ankle-foot orthosis (KAFO) with newly developed 4-bar linkage KAFO on the gait characteristics of persons with poliomyelitis clinically. This 4-bar linkage is the stance control type KAFO which provide the stability during stance phase and knee flexion during swing phase. Two subjects participated in this study voluntarily. We provided the customized 4-bar linkage KAFO then asked the subjects to walk in level surface and stairs under the two different KAFO conditions. The characteristics of gait in the persons with poliomyelitis were evaluated using a 3D motion analysis system and force plate. Additionally 6 minute walk test for physiological cost index were conducted using pulse oximeter to measure the energy consumption. In the results of this study, the differences of 4-bar linkage KAFO compared with ring lock type KAFO are as follows: (1) Walking speed, stride length, and step length on level increased in subjects, (2) The gait symmetry was improved by generated knee flexion and decreased pelvic external rotation on level and stairs walking, (3) Decreased vertical excursion of center of mass and pelvic elevation during swing phase was decreased on level, (4) Knee extension moment, hip flexion moment, hip and knee internal rotation moment of non-braced limb were decreased on level walking, (5) Walking speed in 6-minute walk test was increased and physiological cost index was decreased. These findings indicate that 4-bar linkage KAFO compared with ring lock type KAFO is effective in enhancing pattern, endurance, and energy consumption in level surface and stairs walking.

• Physical Therapy Korea
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• v.7 no.2
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• pp.20-34
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• 2000

The purpose of this study was to establish modified physiological cost index (PCI) for predicting energy consumption by heart rate (HR) at isokinetic ergometer exercise testing. The subjects were twenty-eight healthy men in their twenties. All of them performed upper and lower extremity isokinetic ergometer exercise tests which had six loads (400, 500, 600, 700, 800, and 900 kg-m/min) and five loads (400, 500, 600, 700, and 800 kg-m/min) respectively. The exercise sessions were finished when HR was in plateau. HR and oxygen consumption were determined during the final minute. Resting heart rate and oxygen consumption were used for calculating heart rate, oxygen consumption changes and modified PCI. Regression analysis established the relationship between each variable to work load, HR and oxygen consumption. The results were as follows: 1) In the lower extremity ergometer exercise test, oxygen consumption increased continuously as work load increased, but in the upper extremity ergometer test, oxygen consumption only increased until work load was 700 kg-m/min. 2) HR increased as work load increased in both exercise tests, but in the upper extremity ergometer test, HR decreased from the 700 kg-m/min. 3) The modified PCI increased as work load mcreased until the 700 kg-m/min point in the lower extremity ergometer test and until the 500 kg-m/min point in the upper extremity ergometer test when it started to decrease in both tests. 4) In the lower extremity ergometer exercise test, regression analysis established the relation as $dVO_2$ = -.0215HR - .2141 where $dVO_2$ is given in l/min and HR in beat/min ($R^2$ = .2677, p = .000). ln the upper extremity ergometer exercise test. regression analysis established the relation as $dVO_2$ = -.0115HR + .2746 ($R^2$ = .1308, p = .000). The results of this study were similar to previous studies but were different under high work load conditions. So modified PCI should be used with only low intensity work load testing. Subjects for upper extremity ergometer exercise testing should complete a prescribed training course prior to testing, and only low intensity work load should be used for safety considerations.

• Journal of Korea Multimedia Society
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• v.13 no.7
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• pp.1023-1043
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• 2010

As main memory get cheaper, it becomes increasingly affordable to load entire index of DBMS and to access the index. Since speed gap between CPU and main memory is growing bigger, many researches to reduce a cost of main memory access are under the progress. As one of those, cache conscious trees can reduce the cost of main memory access. Since cache conscious trees reduce the number of cache miss by compressing data in node, cache conscious trees can reduce the cost of main memory. Existing cache conscious trees use only fixed one compression technique without consideration of properties of data in node. First, this paper proposes the DC-tree that uses various compression techniques and change data layout in a node according to properties of data in order to reduce cache miss. Second, this paper proposes the level of compression locality that describes properties of data in node by formula. Third, this paper proposes Forced Partial Decomposition (FPD) that reduces the nutter of cache miss. DC-trees outperform 1.7X than B+-tree, 1.5X than simple prefix B+-tree, and 1.3X than pkB-tree, in terms of the number of cache misses. Since proposed DC-trees can be adopted in commercial main memory database system, we believe that DC-trees are practical result.