• Geomechanics and Engineering
• /
• 제18권4호
• /
• pp.449-457
• /
• 2019

Physical model tests were first performed to investigate the failure pattern of multiple pillar-roof support system. It was observed in the physical model tests, pillars were design with the same mechanical parameters in model #1, cracking occurred simultaneously in panel pillars and the roof above barrier pillars. When pillars 2 to 5 lost bearing capacity, collapse of the roof supported by those pillars occurred. Physical model #2 was design with a relatively weaker pillar (pillar 3) among six pillars. It was found that the whole pillar-roof system was divided into two independent systems by a roof crack, and two pillars collapse and roof subsidence events occurred during the loading process, the first failure event was induced by the pillars failure, and the second was caused by the roof crack. Then, for a multiple pillar-roof support system, three types of failure patterns were analysed based on the condition of pillar and roof. It can be concluded that any failure of a bearing component would cause a subsidence event. However, the barrier pillar could bear the transferred load during the stress redistribution process, mitigating the propagation of collapse or cutting the roof to insulate the collapse area. Importantly, some effective methods were suggested to decrease the risk of catastrophic collapse, and the deep-hole-blasting was employed to improve the stability of the pillar and roof support system in a room and pillar mine.

• Steel and Composite Structures
• /
• 제32권1호
• /
• pp.79-90
• /
• 2019

This study introduces new connections that connect the beam to the column with slit dampers. Plastic deformations and damages concentrate on slit dampers. The slit dampers prevent plastic damages of column, beam, welds and panel zone and act as fuses. The slit dampers were prepared with IPE profiles that had some holes in the webs. In this paper, two experimental specimens were made. In first specimen (SDC1), just one slit damper connected the beam to the column and one IPE profile with no holes connected the bottom flange of the beam to the column. The second specimen (SDC2) had two similar dampers which connected the top and bottom flange of the beam to the column. Cyclic loading was applied on Specimens. The cyclic displacements conditions continued until 0.06 radian rotation of connection. The experimental observations showed that the bending moment of specimen SDC2 increased until 0.04 story drift. In specimen SDC1, the bending moment decreases after 0.03 story drift. Test results indicate the high performance of the proposed connection. Based on the results, the specimen with two slit damper (SDC2) has higher seismic performance and dissipates more energy in loading process than specimen SDC1. Theoretical formulas were extended for the proposed connections. Numerical studies have been done by ABAQUS software. The theoretical and numerical results had good agreements with the experimental data. Based on the experimental and numerical investigations, the high ductility of connection is obtained from plastic damages of slit dampers. The most flexural moment of specimen SDC1 occurred at 3% story drift and this value was 1.4 times the plastic moment of the beam section. This parameter for SDC2 was 1.73 times the plastic moment of the beam section and occurred at 4% story drift. The dissipated energy ratio of SDC2 to SDC1 is equal to 1.51.

• 국제지역연구
• /
• 제15권3호
• /
• pp.535-558
• /
• 2011

본 논문은 FDI를 종속변수가 아닌 설명변수로 삼아 FDI가 제도에 미치는 영향에 초점을 맞춘다. 제도를 Rodrik의 분류방법에 따라 시장조성제도, 시장규제제도, 시장안정화제도 및 시장복지제도 등 4종류로 분류하여 FDI가 제도에 어떠한 영향을 미치는지 분석한다. 1985~2009년 기간 동안 186개국가의 패널자료를 이용하여 후진국과 선진국으로 구분하여 제도결정방정식을 추정한다. 고정모형과 FDI의 내생성을 고려한 system GMM을 이용해서 FDI, FDI와 민주주의의 상호관계항이 4종류의 제도에 미치는 영향에 초점을 맞춘다. 추정결과는 다음과 같다. 첫째, 대부분의 추정결과 FDI는 4종류의 제도에 유의한 양의 영향을 미치지 못하고 있다. 둘째, FDI와 민주주의의 상호관계항은 시장규제제도를 제외한 나머지 3개 종류의 제도에 유의한 양의 영향을 미치고 있다. 즉, FDI는 직접적으로 제도에 영향을 미치지 못하지만, 민주주의가 발달한 경우에 간접적으로 시장조성제도, 안정화제도와 시장복지제도에 영향을 미친다. FDI가 유치국의 제도에 직접적으로 영향을 미치지는 못하지만, 긍정적 영향을 미치기 위해서는 유치국가의 민주주의발달이 필요하다는 점을 알 수 있다.

• 전기전자학회논문지
• /
• 제22권4호
• /
• pp.1056-1061
• /
• 2018

본 연구에서는 건물 외벽 태양광 발전 통합 시스템(BIPV: Building Integrated Photovoltaic System)용 컬러 유리의 구조를 제안하고 이를 구현하기 위한 공정 기술을 개발하였다. 굴절률 값이 다른 두 종류의 산화 금속 박막을 집적함으로써 투과도가 우수하면서도 서로 다른 컬러를 구현할 수 있음을 파동광학에 기반한 전산모사를 통해서 확인하였다. 선택된 구조를 구현하기 위해 RF Magnetron 증착 방법을 통해 목표로 하는 두께를 균일하게 얻을 수 있는 공정을 개발하였다. 실험 시편에 대한 광학적 분석을 전산모사 결과와 비교하여 분석한 결과, 원하는 컬러 유리를 랩 스케일에서 안정적으로 구현할 수 있음을 알 수 있었으며, 상온에서 일주일 이상의 안정성을 갖는 것을 확인하였다. 이러한 기술은 BIPV 건축물을 구축하는 데에 유용할 것으로 기대된다.

• 대기
• /
• 제29권3호
• /
• pp.283-294
• /
• 2019

For the upper air observations, a temperature measurement using radiosonde is a common method, and the compensation of solar radiation effects in the radiosonde temperature sensor is an important factor. In this paper, we present various experiments and compensation methods of the radiosonde temperature sensor to overcome the errors caused by the movement of the radiosonde rotation, etc. The methods and procedures of this study are as follows. First, we used the solar simulator to analyze the temperature variation and solar effect of the temperature sensor in the radiosonde according to the insolation. We also analyzed the temperature variation and solar effect of the temperature sensor according to the incident angle between the solar simulator and radiosonde. Second, we measured and analyzed solar radiation absorbed by solar cells attached to radiosonde. Third, we present combined compensate solution of the first and the second experiment results, to overcome errors caused by insolation effects in the radiosonde temperature sensors. Fourth, we compared that the reference temperature in similar environment with the upper air conditions, to verify the new radiated compensation performance of the radiosonde temperature sensor. Finally, the radiosonde fabricated in this study was raised to the atmosphere, and the laser correction algorithm proposed through experiments was reviewed. As a result of the radiosonde SRS-10 produced in this study, the temperature deviation from Vaisala RS92 was $0.057^{\circ}C$ in nighttime observation, $0.17^{\circ}C$ in daytime observation, It is expected that the GRUAN under WMO will be able to obtain a high test rating of 5.0.

• Journal of the Korean Wood Science and Technology
• /
• 제47권5호
• /
• pp.547-556
• /
• 2019

Thinned, small larch logs have small diameters and no value-added final use, except as wood chips, pallets, or fuel wood, which are products with very low economic value; however, their mechanical strength is suitable for structural applications. In this study, small larch logs were sawed, dried, and cut into square timbers (with a $90mm{\times}90mm$ cross section) that were laterally glued to form core panels used to manufacture cross-laminated timber (CLT) wall panels. The surface and back of these core panels were covered with 12-mm-thick structural plywood panels, used as cross bands to obtain three-ply CLT wall panels. This attachment procedure was conducted in two different ways: gluing and pressing (CGCLT) or gluing and nailing (NGCLT). The size of the as-manufactured CLT panels was $1,220mm{\times}2,440mm$, the same as that of the plywood panels. The final wall panels were tested under lateral shear force in accordance with KS F 2154. As the lateral load resistance test required $2,440mm{\times}2,440mm$ specimens, two CLT wall panels had to be attached in parallel. In addition, the final CLT panels had tongued and grooved edges to allow parallel joints between adjacent pieces. For comparison, conventional light-frame timber shear walls and midply wall systems were also tested under the same conditions. Shear walls with edge nail spacing of 150 mm and 100 mm, the midply wall system, and the fabricated CGCLT and NGCLT wall panels exhibited maximum lateral resistances of 6.1 kN/m (100%), 9.7 kN/m (158%), 16.9 kN/m (274%), 29.6 kN/m (482%), and 35.8 kN/m (582%), respectively.

• 문화기술의 융합
• /
• 제5권1호
• /
• pp.21-26
• /
• 2019

본 논문은 조직의 공정혁신과 마케팅혁신에 따른 혁신 방향과 내부적인 인적자원관리 전략유형 간의 매칭에 따라 기업의 성과(품질경쟁력, 영업이익)가 어떻게 달라지는지에 대해 분석하였다. 분석을 위한 자료는 한국노동연구원(KLI)의 2015년 6회차 사업체패널에 대한 조사로 수집된 3,431개 기업에 대한 자료를 활용하였다. 기업의 혁신은 군집분석을 통해 전체혁신, 부분혁신, 혁신부진의 집단으로 유형화 하였으며, 인적자원관리는 몰입형 인적자원관리와 통제형 인적자원관리의 유형으로 구분하였다. 분석방법은 혁신유형과 인적자원관리 전략유형 간의 매칭을 통해 총 6개의 집단으로 분류하였고, 6개 집단에 속한 기업들이 보이는 품질경쟁력과 영업이익의 평균 차이를 비교하는 분산분석(ANOVA)을 사용하였다. 분석결과 전체혁신-몰입형 인적자원관리 분면의 기업들이 부분적인 혁신이나 혁신부진 집단의 기업들보다 품질경쟁력과 영업이익이 유의하게 높은 결과를 보였으며, 모든 혁신이 부진한 혁신부진-통제형 인적자원관리 분면의 기업들이 그 이상의 기업들 보다 낮은 품질경쟁력과 영업이익을 보여 그 성과가 유의하게 낮은 것으로 나타났다.

• 한국콘텐츠학회논문지
• /
• 제19권5호
• /
• pp.542-552
• /
• 2019

본 연구는 뇌병변장애인의 고용특성 및 취업 영향요인을 확인하는데 목적이 있다. 연구대상은 317명이다. 분석자료는 한국장애인고용공단의 장애인 고용패널조사 자료를 활용하여 카이스퀘어, 회귀분석을 실시하였다. 변수는 장애건강 요인, 취업관련 요인, 가구관련 요인으로 구성된다. 첫째, 뇌병변장애인 취업집단은 미취업집단에 비해 중증장애, 건강상태가 좋은 경우, 일상생활 도움제공자가 없는 경우, 보조도구가 없는 경우, 고학력, 유자격증, 공공취업서비스 경험이 있는 경우, 주변인 취업알선 받은 경우, 직접 구직 문의 경험이 있는 경우, 유배우자, 비수급자, 가족 취업지지가 높은 경우가 유의미하게 나타났다. 둘째, 뇌병변장애인 취업에 영향을 미치는 요인은 일상생활 도움제공자, 학력, 주변인 취업알선 경험, 배우자, 기초생활보장수급으로 나타났다. 결과를 바탕으로 뇌병변장애인의 취업 활성화를 위하여 일상생활, 교육제도, 사회관계망의 강화와 기초생활보장수급제도의 수정에 대해 제시하였다.

• 한국의류학회지
• /
• 제44권5호
• /
• pp.1004-1018
• /
• 2020

Advances in e-commerce enable consumers to shop efficiently for fashion products in global markets in addition, the market size of purchasing directly from foreign websites are also increasing. This study investigates the effects of hedonic and utilitarian shopping values on the continuous use intention of online cross-border shopping. Curiosity and self-efficacy were introduced as mediating variables between shopping values and user intentions. A web-based survey is conducted on female consumers, who have experiences to buy fashion products by online cross-border shopping. A total of 472 responses were collected from a panel of online survey firms. Data are analyzed using confirmatory factor analysis, structural equation modeling, and multi-group SEM by AMOS 21.0. According to the results of the structural equation model test, hedonic value affected continuous use intention of online cross-border shopping as mediated by curiosity and self-efficacy; in addition, utilitarian value influenced self-efficacy, which mediated relations between the utilitarian value and the continuous use intention. The research model was also tested to compare heavy users and light users of online cross-border shopping. For heavy users, the effect of hedonic value on curiosity was significantly stronger than for light users. Several implications are suggested based on the results.

• 한국해양공학회지
• /
• 제35권3호
• /
• pp.173-182
• /
• 2021

The maneuvering performance of a ship on the actual sea is very different from that in calm water due to wave-induced motion. Enhancement of a ship's maneuverability in waves at the design stage is an important way to ensure that the ship navigates safely. This paper focuses on the maneuvering prediction of a Russian trawler in wind and irregular waves. First, a unified seakeeping and maneuvering analysis of a Russian trawler is proposed. The hydrodynamic forces acting on the hull in calm water were estimated using empirical formulas based on a database containing information on several fishing vessels. A simulation of the standard maneuvering of the Russian trawler was conducted in calm water, which was checked using the International Maritime Organization (IMO) standards for ship maneuvering. Second, a unified model of seakeeping and maneuvering that considers the effect of wind and waves is proposed. The wave forces were estimated by a three-dimensional (3D) panel program (ANSYS-AQWA) and used as a database when simulating the ship maneuvering in wind and irregular waves. The wind forces and moments acting on the Russian trawler are estimated using empirical formulas based on a database of wind-tunnel test results. Third, standard maneuvering of a Russian trawler was conducted in various directions under wind and irregular wave conditions. Finally, the influence of wind and wave directions on the drifting distance and drifting angle of the ship as it turns in a circle was found. North wind has a dominant influence on the turning trajectory of the trawler.