• Fire Science and Engineering
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• v.24 no.3
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• pp.93-98
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• 2010

Even though the sprinkler system is a essential fire suppression system, the design engineers do not fully understand the concept of design area which sprinklers operate. They frequently made a mistake to form design area and calculate it. The shape of design area is a square or a rectangle which branch side line is a little longer than the cross main side. NFPA demands to lengthen the branch side to 1.2 times than the cross main side and FM demands 1.4 times. The longer the branch side at the same design area is, the bigger the water quantity and pressure is. At the results of hydraulic calculation of design areas, when the branch side is longer 1.2 times, the water quantity became 4.6% bigger than exact square and the pressure came to 4.67% bigger. When it is longer 1.4 times, the water quantity and the pressure are bigger 7.52%, 14.51%. Therefore, the sprinkler design engineers should follow the general rule of design area, exact square or rectangle which length along the branch line is a little longer than length along the cross main, to design more stable system.

• Nuclear Engineering and Technology
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• v.51 no.8
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• pp.1871-1885
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• 2019

The deterministic MOC code STREAM of the Computational Reactor Physics and Experiment (CORE) laboratory of Ulsan National Institute of Science and Technology (UNIST), was initially designed for the calculation of pressurized water reactor two- and three-dimensional assemblies and cores. Since fast reactors play an important role in the generation-IV concept, it was decided that the code should be upgraded for the analysis of fast neutron spectrum reactors. This paper presents a coupled code - TULIP/STREAM, developed for the fast reactor assembly and core calculations. The TULIP code produces self-shielded multi-group cross-sections using a one-dimensional cylindrical model. The generated cross-section library is used in the STREAM code which solves eigenvalue problems for a two-dimensional assembly and a multi-assembly whole reactor core. Multiplication factors and steady-state power distributions were compared with the reference solutions obtained by the continuous energy Monte-Carlo code MCS. With the developed code, a sensitivity study of the number of energy groups, the order of anisotropic P_N scattering, and the multi-group cross-section generation model was performed on the k_eff and power distribution. The 2D core simulation calculations show that the TULIP/STREAM code gives a k_eff error smaller than 200 pcm and the root mean square errors of the pin-wise power distributions within 2%.

• The Journal of the Korea Contents Association
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• v.15 no.2
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• pp.58-73
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• 2015

In the IoT environment, context information is important to provide context service to the user. For this, collected data from devices such as sensors or actuators, converts to context information using the ontology. Because the existing ontologies designed for target service, if the user wants to change the service requirements, service condition, service environment or another service, overall ontology will be redesigned to the changed service. To overcome this difficulty, we propose the cross-vertical ontology model called the Generic Ontology Models(GOMs). It can define the user's desired services without regarding to place and situation. Also, we propose IoT service concept model that represents data flow of the IoT service and IoT service environment. Moreover, as the use case, we show that the proposed GOMs are able to provide the IoT service well.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.7C
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• pp.712-722
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• 2002

We have investigated a novel optical decoder for a fiber-optic code division multiple access(CDMA) communication systems. The conventional optical encoder and decoder have the advantage of simple structure. However the number of users in the system is limited by the auto- and cross-correlation properties generated in decoding process. In previous studies, to improve the system performance, although they used an optical code that minimize the sidelobe and cross-correlation, could not yet find a novel methods for performance improvement in fiber-optic CDMA system. Thus, it is necessary to investigate the novel optical decode in order to improve the performance of system. In this paper, we schematize the AND gate logic element(AGLE) composed with 1$\times$2 or 1$\times$3 coupler and the optical thyristor and propose the novel optical decoder using K(weight) AGLE. The optical thyristor only passes the overlapped signal and clips other signals. Such a novel concept means that the optical thyristor can operate as a hard-limiter. We analyze the fiber-optic CDMA system using the novel optical decoder with simulation and is found that the novel optical decoder using the AGLE and optical thyristor excludes the sidelobe and cross-correlation intensity between any two sequences.

• Journal of the Korean Institute of Landscape Architecture
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• v.31 no.6
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• pp.28-40
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• 2004

The purpose of this study is to identify the characteristics of monuments in the Seoul Foreigners′ cemetery at Yanghwajin, a place where many prominent Christian missionaries and other Christians have been buried near Choltusan. In considering the characteristics of gravestone details, the researcher has divided the details into 4 analysis categories: forms, symbols, epitaphs, and materials. For this research, 281 monuments were selected including 68 of missionaries, 26 of U. S. Army Soldiers, and 13 of teachers. The analysis revealed that there were 26 types of monuments. This includes simple and standardized types like the tablet, headstone, marker, and monolith. These were used more often than other shaped types such as the Cross, obelisk, sculpture, etc. Standardized types made in Korea have been preferred after the 1950s even though the beauty of the gravestones has been degraded. Symbolical decorations related to religious, social, professional or military emblems were also introduced to strengthen their symbolical objectives. Among them, fie Cross was the most predominant Christian symbol and emblem. The families wanted to inscribe epitaphs, the greater part of which originated from the Bible, poems, idioms related to tribute, rest, supplications to deity, love, achievement, to express human sentiment and religious faith. When using materials for making monuments, monument makers have mostly used stone because of its durability. Until the 1950s, various stones had been used to make monuments, for most marble and granite were brought from foreign countries. These were very different from the Korean white marble stone used for many monuments. After the 1950s, the source of stone has been limited to Korean stone, for Korean could make stone monuments that foreigners were agreeable. Especially, a black marble stone called "O-Suk" which means black stone, has been used as a main material. The study identified the following characteristics of monument details in the Seoul foreigners′ cemetery at Yanghwajin. First, Christianity has been applied as the main concept, while symbolizing the homogeneity of religious, family, social, professional or military groups by having the symbolic form, symbol, and epitaph in common. Second, monuments made after the 1950s have been standardized into unattractive and monotonous forms by the limited materials, and so the beauty of the monuments has been degraded.

• The Journal of Korean Society for School & Community Health Education
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• v.7
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• pp.33-49
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• 2006

Background & Objectives: This study was designed to examine relationships between smoking behavior and smoking attitudes among 6th-grade students in Korea in order to provide knowledge on school-based programs for preventing adolescent smoking behaviors. Methods: Questionnaires were administered to 464 students attending three public elementary schools in O city from June 13 to June 16, 2006. The total sample size is 458 (response rate = 98.7%). Data were statistically analyzed by frequency analysis, cross tabulation, and multiple regression. Results: First, smoking behavior was significantly influenced by the factors of gender, self-concept, family structure, sibling smoking, school achievement, relationship with teachers, satisfaction with school life, and smoking friends. Theprevalence of ever-smoking was 12.7% among 6th grade students in this study. Students were most likely to initiate smoking in the 5thgrade with curiosity and smoke at their own home. Second, students showed negative attitude toward smoking overall. From the detailed section, students respondednegatively about smoking in public places while they thought that adult smoking with moderate level was okay. Student who showed positive attitudes toward smoking in the present study were significantly related to the factors of self-concept, family environment, parental and sibling smoking status, school achievement, satisfaction with school life, and smoking friends. Third, Students who had tried cigarette smoking were likely to report less negative attitudes toward tobacco than non-smoking students. Fourth, this study found that smoking friends were the most significant predictor of positives smoking attitudes. Other factors significantlyassociated with smoking attitudes were gender, relationship with friends, self-concept, relationship with teachers, paternal smoking status. Conclusions: The study results suggest that smoking prevention programs focus on resisting peer influence and need to be community-incorporated and/or comprehensive from elementary to high school.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.3
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• pp.309-318
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• 2012

In advanced stages of periodontal disease, a lot of the periodontal tissue support are usually lost. The tissue destruction around some teeth is progressed to a level which requires either spontaneous exfoliation or extraction of several teeth due to their excessive mobility. In such cases, a comprehensive treatment plan encompassing the adequate periodontal and maintenance therapy, as well as perio-prosthetic treatment involving occlusal equilibration, is needed in order to restore health, function, and esthetics. Cross-arch fixed partial dentures(CAFPDs), one of the perio-prosthetic treatments, are used to stabilize the teeth with severely reduced periodontal tissue support. Unfortunately, however, a little is known about the occlusal scheme and biomechanical concept of CAFPDs. This paper will demonstrate summaries of the trauma from occlusion(TFO), Ante's law revisited, the treatment principles, the role of occlusion, and the long-term consequences for CAFPDs, and the possibility of CAFPDs through a case presentation.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.6
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• pp.228-237
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• 2013

In this paper, we propose a normalized cross correlation(NCC)-based multiview background subtraction method which is robust when an object and background have similar color. When the background of the capturing environment is not artificially composed, the regions in the background images which would be occluded by an object tends to have difference colors. The colors of those regions, however, becomes similar when an object enters the capturing environment. Based on this assumption, this paper proposes a concept of GoNCC(Graph of Normalized Cross Correlation). GoNCC is the distribution of NCC between a pixel in an image and pixels related by epipolar constraints with the pixel. The proposed multiview background subtraction method is performed by comparing GoNCC of the current images with the background images. To reduce computational complexity, we perform multiview background subtraction only to the pixels undetermined by single view background subtraction. Experimental results show that the proposed method is more robust to color similarity between an object and background than a single-view background subtraction method and a previous multiview background subtraction method.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2389-2392
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• 2011

To construct a tunnel to the bottom of the existing tunnels by the behavior of the tunnel to examine the scope and effect, Schubert (1995) Influence Line and Trend Line to the proposed concept was introduced. Crossing angle of the existing tunnels and new tunnels 15, 30, 60, and 90 were set, the lower ground after 3-grade fixed above the ground was graded a 3-grade and 5-grade. Interpreted as a result of these conditions, the tunnel diameter 10m (D) If the crossing angle of around 90 degrees, 60 degrees, 30 degrees or less, each 3.0D, 3.5D, 4.0D, respectively, in the range of the effect could be estimated.

• International Journal of Aeronautical and Space Sciences
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• v.14 no.1
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• pp.19-29
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• 2013

This paper deals with the study of buckling, vibration, and parametric instability characteristics in a damaged cross-ply and angle-ply laminated plate like beam under in-plane harmonic loading, using the finite element approach. Damage is modelled using an anisotropic damage formulation, based on the concept of reduction in stiffness. The effect of damage on free vibration and buckling characteristics of a thin plate like beam has been studied. It has been observed that damage shows a strong orthogonality and in general deteriorates the static and dynamic characteristics. For the harmonic type of loading, analysis was carried out on a thin plate like beam by solving the governing differential equation which is of Mathieu-Hill type, using the method of multiple scales (MMS). The effects of damage and its location on dynamic stability characteristics have been presented. The results indicate that, compared to the undamaged plate like beam, heavily damaged beams show steeper deviations in simple and combination resonance characteristics.