• Composites Research
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• 제31권6호
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• pp.392-397
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• 2018

본 연구에서는 기존의 스틸재 타이로드를 브레이딩 공법을 적용한 탄소복합재로 개발하고자 하였다. 탄소복합재 타이로드는 기존 제품과 동등한 성능을 만족시키기 위하여 브레이딩 직조에 필요한 코어 단면설계, 코어와 탄소섬유의 접합부에 대한 구조형상설계를 진행하였다. 그리고 브레이딩 공법을 적용한 시편을 제작하여 시험평가를 통해 구조해석에 적용하였다. 제작 공정은 브레이딩 직조 후 인퓨전 공정을 거쳐 후경화 공정까지 진행하였으며 최종 제품에 대한 시험평가는 인장 시험, 비틀림 시험, 압축 시험과 피로시험을 순차적으로 진행하여 모두 만족시켰다. 또한 탄소복합재 타이로드의 중량을 기존 제품 대비 약 37% 정도 경량화시킬 수 있었다.

• KIEAE Journal
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• 제4권1호
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• pp.11-20
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• 2004

Innovative daylighting systems in buildings in various climatic zones around the world have been developed under the IEA SHC Task21. The performance assessment were obtained by monitoring the most systems using full-scale test model rooms or actual buildings under real sky conditions. This study aims to analyze the configuration and monitoring system of the nine Mock-up models of the IEA SHC Task21 comparatively. For the purpose, the geometry of the test rooms (length, width, height, window area, glazed area and occupied), reflectance of walls, floor and ceiling, transmittance of glazing (transmittance for hemispherical irradiation, normal irradiation and U-value) were compared. And equipment for measurement (manufacturer, range, calibration, maximum calibration error, cosine response error, fatigue error), and data acquisition system (manufacturer, type, number of differential analogue input channels, A/D converter resolution in bits, data acquisition software) were also analyzed comparatively. Some findings of these experimental methodology of standard monitoring have been proven to be a valuable one for future assessment of advanced daylighting systems in our country.

• 한국가스학회지
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• 제6권4호
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• pp.17-22
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• 2002

LNG는 여러 가지 장점으로 해마다 수요가 크게 늘고 있으며 이에 따른 LNG 저장설비의 건설과 확장 또한 급속도로 증가하고 있다. LNG 저장탱크에서 가장 중요한 요소중의 하나는 스테인레스 조재로 제작된 멤브레인이다. 멤브레인은 LNG 온도에 따른 열수축과 팽창을 흡수하는 주름을 가지고 있는 스테인레스 판으로 안정적 변형과 충분한 파괴강도를 확보하여야 한다. 따라서 본 논문에서는 개발된 Kogas 멤브레인의 변형과 강도를 실험적으로 수행되었고 모든 결과들이 관련 규격을 만족하는 것으로 나타났다.

• 한국군사과학기술학회지
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• 제19권5호
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• pp.559-566
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• 2016

Cables for Towed Array Sonar System(TASS) were developed. In order to verify the performance of cables, environmental and operational conditions as well as functional requirements were investigated during design stage. Double armored high and low voltage integrated cable for towed body and two kinds of cables, armored and light weight power and optic hybrid cables for towed array sensor system were developed by modeling and simulation. Customized manufacturing process and test method, such as foam extrusion and dynamic fatigue test were applied to this development. In conclusion, underwater towed hybrid cable with high tensile strength and compact structure were developed.

• 한국컴퓨터정보학회논문지
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• 제24권10호
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• pp.195-203
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• 2019

군 내 복무 부적응 병사들로 인한 병영사고는 비전투력 손실에 따른 전투력 약화, 대군 신뢰도 저하 등 많은 문제를 유발한다. 군은 복무 부적응 병사들을 사전에 식별하고 사고를 예방하기 위한 심리검사체계로 신인성검사를 개발, 적용하고 있다. 본 논문에서는 사고 우려자를 식별하기 위해 부적응 병사의 행동 패턴과 증상을 온톨로지로 구현하기 위한 온톨로지 설계 프로세스를 제안한다. 온톨로지 설계 프로세스에 따라 설계한 온톨로지의 성능 평가 결과, 적합성 및 효과성이 검증되었다. 온톨로지 설계를 통해 부적응 병사를 식별하기 위한 군 내 객관적인 기준을 제시하고 사고 우려자에 관한 정보를 공유함으로써 사고 예방에 효과적인 역할을 할 것으로 기대된다.

• Steel and Composite Structures
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• 제42권6호
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• pp.765-777
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• 2022

Ultra high performance concrete (UHPC) can be used in the UHPC-steel composite structures especially for bridge structures to achieve high stiffness and high fatigue resistance with low self-weight. The structural performances of UHPC-steel composite slabs subjected to hogging moment have a significant influence on the global stiffness and durability of UHPC-steel composite structures. In order to study the structural behaviors of non-steam-cured UHPC-steel composite slabs subjected to negative moment, five composite slabs combined the thin UHPC layers to steel plates via shear stud connecters with the diameter of 16mm were fabricated and tested under negative moment. The test program aimed to investigate the effect of stud spacing and longitudinal reinforcement ratios on the failure mode, load-deflection behaviors, cracking patterns, bond-slips, and carrying capacities of composite slabs subjected to negative moment. In addition, direct tensile tests for the dog-bone UHPC specimens with longitudinal reinforcement bars were carried out to study the effect of reinforcement bars on the tensile strength of UHPC in the thin structure members. Based on the experimental results, analytical models were also developed to predict the cracking load and ultimate load of UHPC-steel composite slabs subjected to negative moment.

• Journal of Biosystems Engineering
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• 제24권2호
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• pp.99-106
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• 1999

This study was conducted to provide a direction for improving the performance of triangular-type belt clutch. The power transmission characteristics and the wear of belt were investigated for two types of pulley set theoretically and experimentally. The results of research were summarized as follows: 1) Based on the theoretical analysis for the life time of belt, the wear of belt could be reduced by increasing the sizes of driving V-pulley and tension pulley, and by decreasing the tension on V-belt. 2) The pulley set # 2 could transmit more power than the pulley set # 1 could at the same slop rate. While the slip rate was 2.36% on the pulley set # 2 at the maximum power transmission, the slip rate on the pulley set # 1 was increased up to 12.2% at the same condition. 3) From the 16 hours' fatigue test, the wear of belt used n the pulley set # 1 was observed severer than that in the pulley set#2. Also, it was found that the tensile strength of belt used in the pulley set # 2 was greater than that of belt used in the pulley set # 1.

• Smart Structures and Systems
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• 제1권2호
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• pp.141-158
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• 2005

A new design of distributed crack sensors based on the topological change of transmission line cables is presented for the condition assessment of reinforced concrete (RC) structures during and immediately after an earthquake event. This study is primarily focused on the performance of cable sensors under dynamic loading, particularly a feature that allows for some "memory" of the crack history of an RC member. This feature enables the post-earthquake condition assessment of structural members such as RC columns, in which the earthquake-induced cracks are closed immediately after an earthquake event due to gravity loads, and are visually undetectable. Factors affecting the onset of the feature were investigated experimentally with small-scale RC beams under cyclic loading. Test results indicated that both crack width and the number of loading cycles were instrumental in the onset of the memory feature of cable sensors. Practical issues related to dynamic acquisition with the sensors are discussed. The sensors were proven to be fatigue resistant from shake table tests of RC columns. The sensors continued to show useful performance after the columns can no longer support additional loads.

• 한국건축시공학회지
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• 제23권4호
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• pp.393-404
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• 2023

본 연구에서는 구리입자를 이용한 항균 UV경화도료를 제조하고 투명성을 평가한 결과 일반 UV경화도료와 동등이상인 90%이상의 전광선투과율을 나타내었다. 실란커플링제로 표면 개질한 구리입자가 20wt% 첨가된 항균 UV경화도료를 코팅한 항균 목질 마루판의 피로 시험 전후의 항균 성능 평가 결과 6시간 후 세균감소율이 99.9% 로 우수한 항균 성능을 나타내었다.

• Journal of Preventive Medicine and Public Health
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• 제53권6호
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• pp.447-454
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• 2020

Objectives: The aim of the present study was to investigate the relationships among hospital safety climate, patient safety climate, and safety outcomes among nurses. Methods: In the current cross-sectional study, the occupational safety climate, patient safety climate, and safety performance of nurses were measured using several questionnaires. Structural equation modeling was applied to test the relationships among occupational safety climate, patient safety climate, and safety performance. Results: A total of 211 nurses participated in this study. Over half of them were female (57.0%). The age of the participants tended to be between 20 years and 30 years old (55.5%), and slightly more than half had less than 5 years of work experience (51.5%). The maximum and minimum scores of occupational safety climate dimensions were found for reporting of errors and cumulative fatigue, respectively. Among the dimensions of patient safety climate, non-punitive response to errors had the highest mean score, and manager expectations and actions promoting patient safety had the lowest mean score. The correlation coefficient for the relationship between occupational safety climate and patient safety climate was 0.63 (p<0.05). Occupational safety climate and patient safety climate also showed significant correlations with safety performance. Conclusions: Close correlations were found among occupational safety climate, patient safety climate, and nurses' safety performance. Therefore, improving both the occupational and patient safety climate can improve nurses' safety performance, consequently decreasing occupational and patient-related adverse outcomes in healthcare units.