• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.10
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• pp.4660-4668
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• 2012

The purpose of this study was to investigate the relationship among stress, ego-resilience and school adjustment resilience of the high school girl students. A cross-sectional, descriptive study was conducted. The subjects were 250 students from 3 high schools located in I city. Data were collected on September, 2010 by using a structured questionnaire. The data were analyzed using PASW/WIN 18.0 program. The mean score of stress was 3.05, among the subitems, the score of the school related stress was the highest. The mean score of ego resilience was 2.86, and school adjustment resilience was 75.58. Stress showed significant differences according to satisfaction level with school and teachers. School adjustment resilience was significantly different in terms of satisfaction level with school and teachers, grade, alcohol drinking experience and having counter sex friends. And there were significant correlations among school adjustment resilience and school related, family related, friend related stress. These results suggest that the school life, teachers, and friends have important duties to improve school adjustment resilience. Therefore, it is needed to develop intervention program considerated school related factors to release stressors of the high school girl students.

• Journal of the Korean Wood Science and Technology
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• v.44 no.1
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• pp.40-47
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• 2016

Instead of metal connector generally used on the structural glued laminated timber rahmen joints, the GFRP reinforced laminated plates combining veneer and GFRP (Glass Fiber Reinforced Plastic) and bonded type GFRP rod were used as the connectors. As a result of moment resistance performance evaluation on the joint part applied with these connectors, the yield moment of specimen using the GFRP reinforced laminated plates and GFRP rod pin was measured 4 % lower in comparison to the specimen (Type-1) using the metal connectors, but the initial rotational stiffness was measured 29% higher. Also, the yield moment and rotational stiffness of the specimen using the GFRP-reinforced laminated plates and wood (Eucalyptus marginata) pin showed were measured 11% and 56% higher in comparison to the Type-1 specimen, showing the best performance. It was also confirmed through the failure shape and perfect elasto-plasticity analysis that it showed ductility behavior, not brittle fracture, from the shear resisting force by the pin and the bonding strength increased and the unification of member was carried out. On the other hand, in case of the specimen bonded with GFRP rod, it was impossible to measure the bonding performance or it was measured very low due to poor bonding.

• Magazine of the Korea Concrete Institute
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• v.11 no.2
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• pp.147-156
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• 1999

An investigation was conducted into the flexural behavior of earthquake damaged reinforced concrete columns repaired with carbon fiber sheets. Six column specimens were tested to failure under reversed cyclic loading. Two columns were specimens for control with no sheets and tested. These columns were repaired with carbon fiber sheets and retested to evaluate the effect of the confinement of the carbon fiber on the damaged column. Another two columns were repaired and tested with no pre-cyclic loading. The test specimens were designed to model single bent under a constant axial force with reversed cyclic lateral loading. Carbon fiber sheets were used to repair damaged concrete columns in the critically stressed areas near the column footing joint and the physical, mechanical properties of carbon fiber sheets are described. The performance of repaired columns in terms of their hysteretic response is evaluated and compared to those of the original columns. The results indicate that the repaire technique with carbon fiber sheets is highly effective. Both flexural strength and displacement ductility of repaired columns were higher than those of the original columns.

• Magazine of the Korea Concrete Institute
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• v.7 no.3
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• pp.199-210
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• 1995

We could say that the concrete filled steel tube structure is superior in the vlew of various structure properties as to promote improvement of structural capacity to dtmonstrate heterogeneous material properties interdependently. The compressive strength is increased by putting to tri axial stress because lateral expansion of concrete 1s confined by the steel tube, when concrete conflned by steel tube fall under centric axial load. Also, it have an advantage that decreasr of load carrying capacity 1s small, not occuring section deficiency due to protect falling piienornonon by co~nprrssion fallurc of concrete. So this study investigated for structural behaviors yroprrtiex of concwir. confined by steel tube throughout a series of experlmerit with kcy parxncter, such as diameter-to-thickness(D / t) ratio, strength of concrete as a study on properties of structural behaviors of confined concrete confined by circular steel tube( tri axial stress). Frorn the expcrment results, the obtained results, are surnrnarised as foliow. (1) The restraint effect of concrete by steel tube was presented significantly as the D /t ratio of steel tube and the strength of filled concrete decrease, and the confined concrete by circular steel tube was increased respectively twice as much as 4-7 in deformation capacity at the ultimate strength ,compared with those of non-confined concrete, so expected to increase flexible effect of concrete. (2) The emprical formula to predict the ultimate capacity of confined concrete by steel tube and concrete filled steel tube column using restraint coefficient of concrete were proposed.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.94-94
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• 2003

최근, 새로운 전자재료로서 GaN 분말의 합성과 응용에 관한 연구가 많이 이루어지고 있다. CaN 분말은 열처리 과정 중 분해를 방지하기 위한 표면 보호용 소재, CaN 박막 또는 벌크 결정을 성장하기 위한 precursor 및 대면적 평판표시소자 제작을 위한 전기발광소자용 소재 등에 적용되고 있다. 일반적으로 100$0^{\circ}C$ 이상의 온도에서Ga과 NH$_3$를 반응시키거나, Ga이 포함된 화합물반도체 또는 산화물 및 질산염 등을 NH$_3$ 분위기에서 가열시켜 GaN 분말을 합성시키고 있다. 본 논문에서는 출발물질로서 GaOOH를 채택하고, 이를 NH$_3$ 가스를 흘리면서 가열 반응시켜 GaN 분말을 합성하고 X선 회절분석 방법을 사용하여 GaN의 합성에 대한 반응기구를 조사하였다. GaN 분말을 합성하기 위하여 GaOOH 분말 1g을 석영 용기에 담아 석영 반응관 내에 위치시키고, 반응관 내부를 $10^{-3}$ torr의 진공으로 배기한 후 $N_2$를 주입하면서 전기로의 온도를 1$0^{\circ}C$/min으로 승온시켰다. 반응온도는 300~l17$0^{\circ}C$의 범위에서 변화시켰고, 반응시간은 10분부터 24시간까지 변화시켰으며, NH$_3$의 유량은 300~700 sccm의 범위에서 변화시켰다. GaN의 반응역학을 조사하기 위하여 X선 회절도에서 특정 성분의 회절강도는 시료 내에 포함된 특정 성분의 량에 직접 비례한다고 가정하고, 2$\theta$=37$^{\circ}$부근에서 관찰되는 GaN의 (101)면에 의한 회절강도를 측정하고, 이를 GaN의 생성량으로 고려하였다.}C$로 소결 하였다. coating 결과 박리현상은 없었으나, 표면과 단면의 SEM분석결과 다소 porous한 박막층이 형성되었으며, Ca이온이 지지체로 permeation되는 현상이 발생하였다. 이와 같은 결과로부터 보다 치밀한 박막생성을 위해, slurry 제조조건을 변화시켰으며, Ca이온의 migration을 막기 위해 barrier layer를 이용하였다 완전 소결된 지지체는 가스투과도와 전기전도도측정을 통하여 특성을 평가하였다.였다.다.m이하의 NH$_3$ 가스를 검출할 수 있었다.기 화강암 관입 이전에 좌수향 전단 운동에 의해 부분적으로 재활성 되었으며, 후기 화강암의 관입 이후에 재차 우수향 전단운동으로 활성화 되었음을 알 수 있다. 이상의 결과를 종합하면 호남전단대는 쥬라기 중기에 발생한 광역적인 우수향의 연성전단운동이나, 운동 특성은 연속적이기 보다는 단속적으로 일어난 것으로 생각된다.리 폐 관류는 정맥주입 방법에 비해 고농도의 cisplatin 투여로 인한 다른 장기에서의 농도 증가 없이 폐 조직에 약 50배 정도의 고농도 cisplatin을 투여할 수 있었으며, 또한 분리 폐 관류 시 cisplatin에 의한 직접적 폐 독성은 발견되지 않았다이 낮았으나 통계학적 의의는 없었다[10.0%(4/40) : 8.2%(20/244), p>0.05]. 결론: 비디오흉강경술에서 재발을 낮추기 위해 수술시 폐야 전체를 관찰하여 존재하는 폐기포를 놓치지 않는 것이 중요하며, 폐기포를 확인하지 못한 경우와 이차성 자연기흉에 대해서는 흉막유착술에 더 세심한 주의가 필요하다는 것을 확인하였다. 비디오흉강경수술은 통증이 적고, 입원기간이 짧고, 사회로의 복귀가 빠르며, 고위험군에 적용할 수 있고, 무엇보다도 미용상의 이점이 크다는 면에서 자연기흉에 대해 유용한 치료방법임에는 틀림이 없으나 개흉술에 비

• Journal of the Korea Concrete Institute
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• v.17 no.1 s.85
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• pp.121-128
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• 2005

A RC column-bent pier represents one of the most popular piers used in highway bridges. Seismic performance of reinforced concrete (RC) column-bent piers under bidirectional seismic loadings was experimentally investigated. Six column bent-piers were constructed with two circular supporting columns which were made in 400 mm diameter and 2,000 mm height. One single column specimen was additionally made to comparatively evaluate the seismic response of RC column-bent piers. Test parameters are different transverse reinforcement and loading pattern. These piers were tested under lateral load reversals with the axial load of $0.1 f_{ck}A_g$. Three specimens were subjected to bidirectional lateral load cycles which consisted of two main longitudinal loads and two sub transverse loads in one load cycle. Other three specimens were loaded in the opposite way. Test results indicated that lateral strength and ductility of the latter three specimens were generally bigger than those of the former three specimens. Plastic hinges were formed with the spall of cover concrete and the fracture of the longitudinal reinforcing steels in the bottom plastic hinge of two supporting columns for the former three specimens. Similar behavior was observed in the top and bottom parts of two supporting columns for the latter three specimens.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.4A
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• pp.331-340
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• 2011

The application of newly developed fiber-sheet and steel-plate composite plate (FSP) as a means of improving strength and ductility capacity of concrete cylinders under axial compression load through confinement is investigated experimentally in this study. An experimental investigation involves axial load tests of two types of FSP strengthening material, two anchoring methods, and three concrete strengths. The FSP-confined cylinder tests showed that FSP provided a substantial gain in compressive strength and deformability. The performance of FRP-confined cylinders was influenced by type of the FSP strengthening material, the anchoring method, and concrete compressive strength. The FSP failure strains obtained from FSP-confined cylinder tests were higher than those from FRP-confined cylinder tests. The magnitude of FSP failure strain was related to the FSP composite effectiveness. The effects of FSP confinement on the concrete microstructure were examined by evaluating the internal concrete damage using axial, radial, and volumetric strains. From the observations obtained in this investigation, it is believed that FSP is one of the best solutions for the confinement of concrete compressive members.

• Science of Emotion and Sensibility
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• v.14 no.4
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• pp.627-636
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• 2011

The purpose of this study is to develop the multi-modal interaction system. This system provides realistic and an immersive experience through multi-modal interaction. The system recognizes user behavior, intention, and attention, which overcomes the limitations of uni-modal interaction. The multi-modal interaction system is based upon gesture interaction methods, intuitive gesture interaction and attention evaluation technology. The gesture interaction methods were based on the sensors that were selected to analyze the accuracy of the 3-D gesture recognition technology using meta-analysis. The elements of intuitive gesture interaction were reflected through the results of experiments. The attention evaluation technology was developed by the physiological signal analysis. This system is divided into 3 modules; a motion cognitive system, an eye gaze detecting system, and a bio-reaction sensing system. The first module is the motion cognitive system which uses the accelerator sensor and flexible sensors to recognize hand and finger movements of the user. The second module is an eye gaze detecting system that detects pupil movements and reactions. The final module consists of a bio-reaction sensing system or attention evaluating system which tracks cardiovascular and skin temperature reactions. This study will be used for the development of realistic digital entertainment technology.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.10
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• pp.1881-1891
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• 2000

Cenosphere particles of different fly ash formed at the pulverized coal power plant were hollow sphere or filled with small particles inside solid particles. And size was relatively larger than other fly ash particles as well as specific gravity was small to suspend in the water. In this paper, it was demonstrated to contain a variety of morphological particle type, and the physical and chemical properties related to the cenosphere and fly ash particles. Furthermore it was estimated the possibility to reuse the cenosphere particles on the base of cenosphere properties. Cenosphere formation resulted from melting of mineral inclusion in coal, and then gas generation inside the molten droplet. As the aluminosilicate particle was progressively heated, a molten surface layer developed around the solid core. Further heating leaded to cause the formation of fine particles at the core. The mass median diameter(MMD) of cenosphere particles was $123.11{\mu}m$ and the range of size distribution was $100{\sim}200{\mu}m$ with single modal. It was represented that specific density was $0.67g/cm^3$ fineness was $1135g/cm^3$. The chemical components of cenosphere were similar to other fly ash including $SiO_2$, $Al_2O_3$, but the amount of the chemical component was different respectively. In the case of fly ash, $SiO_2$ concentration was 54.75%, and $Al_2O_3$ concentration was 21.96%, so this two components was found in 76.71% of the total concentration. But in the case of cenosphere, it was represented that $SiO_2$ concentration was 59.17% and $Al_2O_3$ concentration was 30.16%, so this two components was found in 89.33% of the total concentration. Glassy component formed by the aluminosilicate was high in the cenosphere, so that it was suitable to use insulating heat material.

• Polymer(Korea)
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• v.33 no.5
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• pp.446-451
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• 2009

Reliability evaluations of linear low density polyethylene (LLDPE) pipe with respect of thermal exposure time have been investigated in accordance with RS M 0042, which is a reliability standard for polymer pipe. As the thermal exposure time is prolonged, a progressive increase, until 250 days, in tensile strength and a slight increase in hardness are observed, while a proportional decrease in elongation at break is showed. These results can be explained by the increase of crystallinity, followed by the increase of crosslinking density, chain scission and the decrease in chain mobility, due to thermal oxidation as the exposure time increases. Long term hydrostatic pressure test result implies the existence of transition point from ductile to brittle fracture. Oxidation induction time (OIT) test is employed to monitor the thermo-oxidative degradation of LLDPE pipe. This result shows that after the exposure time is 250 days, the depletion of antioxidants added in LLDPE pipe occurs. An empirical equation as function of exposure time, under $100^{\circ}C$ thermal-degradation condition, is proposed to assess the remaining amount of antioxidants owing to thermo-oxidative degradation. Fourier transform infrared spectroscopy results show the increase of carbonyl (-C=O) and hydroxyl (O-H) function groups on the surface of thermally exposed LLDPE pipe. This result suggests that the hydrocarbon groups locally undergo the oxidation on the LLDPE surface due to thermal-degradation.