• Smart Structures and Systems
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• 제23권6호
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• pp.695-702
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• 2019

The number of cable-stayed bridges has been increasing worldwide, causing issues in maintaining the structural safety and integrity of bridges. The stay cable, one of the most critical members in cable-stayed bridges, is vulnerable to wind-induced vibrations owing to its inherent low damping capacity. Thus, vibration mitigation of stay cables has been an important issue both in academia and practice. While a semi-active control scheme shows effective vibration reduction compared to a passive control scheme, real-world applications are quite limited because it requires complicated equipment, including for data acquisition, and power supply. This study aims to develop an Arduino-based integrated cable vibration control system implementing a semi-active control algorithm. The integrated control system is built on the low-cost, low-power Arduino platform, embedding a semi-active control algorithm. A MEMS accelerometer is installed in the platform to conduct a state feedback for the semi-active control. The Linear Quadratic Gaussian control is applied to estimate a cable state and obtain a control gain, and the clipped optimal algorithm is implemented to control the damping device. This study selects the magnetorheological damper as a semi-active damping device, controlled by the proposed control system. The developed integrated system is applied to a laboratory size cable with a series of experimental studies for identifying the effect of the system on cable vibration reduction. The semi-active control embedded in the integrated system is compared with free and passive mode cases and is shown to reduce the vibration of stay-cables effectively.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.518-521
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• 2005

The Structures or buildings nowadays draw more complexity in design due to space limitation and other factor that affect the height and dimensions, that results to instability. So the various methods have been carried out to improve the safety factor from an earthquake or a boom until recently. But, it is very hard to get model precisely because these structures are the non-linear and multi-variable systems. For this reason, we developed the active control system that is applied the adaptive control method on the U type Tuned Liquid Damper(TLD) passive control system. It is proven that the proposed active control strategy of the plate carrying U type TLD system is the more effective control method to suppress the vibration of the structure. The entire hybrid control system is composed of the actuator acted in the opposite direction of the TLD system's motion direction and the active control device with an air pressure adjuster. This paper proposed the adaptive control methods to improve the problem of U type TLD system which is used widely for the passive control of the building. And it is proved by the simulation. In advanced, it is developed the pressure control method that is improved the hybrid controller's performance by using air chamber pressure controller. These methods take the advantage of the decrease of the maximum displacement by using the controller as soon as the impact is loaded. This is a very important element for the safety design and economic design of structures.

• 한국자동차공학회논문집
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• 제24권3호
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• pp.310-318
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• 2016

The demands for vehicle safety systems such as ABS and ESC have been increased. Accurate vehicle state estimation is required to realized the abovementioned systems and tire-friction coefficient is crucial information. Estimation of lateral tire-road friction coefficient using pneumatic trail information is mainly dealt in this paper. Pneumatic trail shows unique characteristics according to the wheel side slip angle and these property is highly sensitive to vehicle lateral motion. The proposed algorithm minimizes the use of conventional tire models such as magic formula, brushed tire model and Dugoff tire model. The pure side slip maneuver, which means no longitudinal dynamics, is assumed to achieve the ultimate goal of this paper. A simulation verification using Carsim and Simulink is performed and the results show the feasibility of the proposed algorithms.

• 대한안전경영과학회지
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• 제17권4호
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• pp.275-286
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• 2015

Global interests in RFID are increased and Korean government and companies make an active effort to propagate and spread RFID. Due to the overwhelming advantages of RFID system in comparison with existing bar code system, ripple effects on logistics sector among the utilizing fields of RFID technology are expected to be great, but application of RFID system is lowly progressed unlike the expectation of several experts. Therefore, this research extracts precedent studies on theoretical background, applying fields, promotion condition and domestic/foreign parts of RFID system, factors for operating domestic RFID system and effects and considers the effects of RFID's external variables on easiness and effectiveness of TAM. It confirms the relations of RFID applying effects for companies applying and utilizing RFID and verifies the relations among the effects for application of RFID system, accepting intention of RFID system and applying effects. Based on the results of analysis, it should play a role of good guide for all of companies and institution who will introduce RFID system to all of Korean logistics fields, make policies and systems which promote RFID acceptance nationally and socially and play a role of guide making confident climate for RFID technolog

• 한국가스학회지
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• 제22권6호
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• pp.76-89
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• 2018

지속적인 산업 발전에 따른 에너지 수급의 불안정 및 환경오염 문제가 대두됨에 따라 이에 대한 해결 방안의 일환으로 열병합발전 시스템의 보급이 활발해지고 있다. 국내의 경우 가스엔진을 이용한 열병합발전기의 안전성능에 대한 검사기준이 미비하므로 이에 대한 연구가 필요한 실정이다. 본 연구에서는 20 kW급 가스엔진 열병합발전 시스템에 적용 가능한 안전성능 관련 표준화 연구 수행을 위해 열병합발전 시스템의 국내 외 기준에 대한 안전성능 및 구조/재료 평가기준을 분석하였다. 또한, 위험요소 분석 및 HAZOP (Hazard and Operability Studies)을 이용한 위험성평가를 수행하여 가스엔진 열병합발전 시스템의 안전성능 평가(안)을 도출하였으며, 평가항목으로는 안전성능 관련 엔진 시동, 배관 기밀 성능, 살수 및 온도 상승 성능, 연소 성능, 전기 효율, 열효율, 종합 효율, 습도 성능 등이 포함된다. 가스엔진 열병합발전 시스템의 구조 및 재료와 관련하여 가스 및 수배관, 가스 조절 및 차단밸브, 금속 또는 비금속 재료의 내구성, 내열성, 내한성에 대한 평가항목을 도출하였다.

• 한국지역사회생활과학회지
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• 제18권1호
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• pp.189-204
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• 2007

This review was to suey the status of agricultural diseases, injuries and accidents among England, the USA, France, Japan, and Korea. For this purpose, detailed research objectives were to analyze the current national status of agricultural diseases, injuries and accidents in Korea and four foreign countries. To do so, related literature such as books, theses, articles, and web documents were collected and analyzed. The implications for industry and agricultural safety and health, diseases, occupational injuries and accidents of farmers thereby derived were as follows: 1) efforts on unifying administrative systems, 2) special support and management systems focusing on neglected subjects, 3) committees for collecting opinions and suggesting alternative policies on the behalf of various financiers, 4) aligned strategies including vision, goals, and long-term plans about national safety and health projects, 5) development of supporting systems considering the features of agriculture, 6) systematized national surveys about occupational injuries and accidents for basic statistics and national studies, 7) active prevention efforts against occupational injuries and accidents, and 8) specialized funds for the safety and health of farmers.

• 한국산업보건학회지
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• 제17권2호
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• pp.89-100
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• 2007

Object: The purpose of this study was to survey the government official support status of the agricultural diseases, injuries and accidents among Korea and foreign countries and to suggest the agricultural policy of Korea. Methods: For this purpose, we analyzed the current national management support status among four foreign countries and Korea about agricultural diseases, injuries and accidents of farmers. For the foreign countries and the national support current status of agricultural diseases, injuries and accidents, related literature such as books, theses, articles, and web documents from the government organization of each countries were collected and analyzed. Key words for web-site and web documents were agricultural diseases, injuries, and accidents, government official system, safety and health, farmer's welfare, and farmer's official support system. UK, United States of America, France, and Japan were selected as the foreign countries' cases. Results and Conclusions: Implications for the agricultural diseases, injuries and accidents derived from the reviews among foreign countries and Korea were as follows: governmental supports should include (1) efforts on unifying administrative systems, (2) special support and management systems focusing on special subjects such as the agriculture that have been neglected, (3) aligned strategies including vision, goals, long-term plans about national safety and health projects, (4) development of supporting systems considering the features of agriculture, (5) systemized national surveys about occupational injuries and accidents for basic statistics and national studies, (6) active prevention efforts of agricultural diseases, injuries and accidents, and (8) specialized funds for safety and health of Korean farmers.

• Steel and Composite Structures
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• 제20권4호
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• pp.801-812
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• 2016

In an actual design, none of the structures with shear behaviors will be designed for torsional moments. Any failure or damages to roofs, infills, shear walls, and braces caused by an earthquake, will inevitably result in relocation of center of mass and rigidity of the structure. With these changes, the dynamic characteristics of structure could be changed during an earthquake at any moment. The main objective of this paper is to obtain the relationship between time-varying eccentricity of load and corner lateral displacement. In this study, various methods have been used to determine the structural response for time-varying lateral corner displacement. As will be seen below, some of the structural calculation methods result in a significant deviation from the actual results, although these methods include the interaction effects of modes. Controlling the lateral displacement of structure can be performed in different ways such as, passive dampers, friction dampers, semi-active systems including the MR damper and active Systems. Selecting and locating these control systems is very important to bring the maximum safety with minimum cost into the structure. According to this study will be show the relation between the corner lateral displacements of structure and time-varying eccentricity by different kind of methods during an earthquake. This study will show that the response of the structure at the corners due to an earthquake can be very destructive and because of changing the eccentricity of load, calculating the maximum possible response of system can be carried out by this method. Finally, some kind of systems must be used for controlling these displacements. The results shows that, the CQC, DSC and exact methods is comply each other but the results of Vanmark method is not comfortable for these kind of buildings.

• 한국산학기술학회논문지
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• 제21권1호
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• pp.457-467
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• 2020

세계적으로 환경문제에 관한 우려가 급증하여, 세계 각국이 온실가스 연비 규제를 강화하고 있다. 연비향상을 위해 첨단 운전자 지원 시스템을 이용한 연구를 통하여, 운전자의 편의를 위해 다양한 첨단 운전자 지원 시스템을 개발하고 있다. 그중 ACC, LKAS, AEB 등의 시스템에 대한 연구가 활발하다. ACC의 목적은 차량의 종 방향 속도와 거리를 제어하고 운전자의 부하를 최소화하여 사고 예방과 방지에 유용한 시스템으로 평가되고 있다. 이러한 관점에서 본 논문은 선행연구에서 제안한 국내도로 환경을 고려한 시나리오와 거리에 대한 함수로 안전성을 평가할 수 있는 수학적 방법을 활용한다. 또한, 제안한 시나리오를 기반으로 시뮬레이션과 실도로 실차시험을 진행한 뒤, 이론수식을 활용한 이론 계산값, 시뮬레이션과 실도로 실차시험의 상대거리의 비교분석을 통하여 ACC의 기능적인 안전성을 검증하고자 한다. 이러한 방법을 통하여 많은 회사들이 ACC의 개발 단계에서 시나리오, 수식, 시뮬레이션을 활용하여 안전성 평가방법으로 활용할 수 있을 것으로 예상된다.

• 한국치위생학회지
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• 제17권5호
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• pp.769-777
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• 2017

Objectives: The study was to promote patient safety by analyzing the effect of dental hygienist's perception of patient safety culture on infection control activities. Methods: The study is based on a survey of 377 dental hygienists in total working in dental settings. The questionnaire consisted of 119 questions, including 34 questions on perception of patient safety culture, and 85 questions on infection control activities. Hierarchical regression analysis was used to examine the relationship between the perception of patient safety culture and infection control activities. The data was analyzed using the SPSS version 20.0, and p<0.05 was adopted to decide on significance. Results: The longer dental hygienists have worked n the dental settings, the more active they become in infection control activities. Among the different types of dental care settings, general (university) hospitals had the largest number of infection control activities, followed by dental clinics, and network dental clinics, in descending order. The dental settings possessing a higher number of dental hygienists were found to conduct more infection control activities than other dental settings. In addition, it was found that when a dental setting adopts a patient safety policy across all the units in the hospital, more systems and procedures for patient safety tend to be established, and that stricter management response to error leads to improvement of infection control activities. Conclusions:In order to enhance infection control activities, infection control activity programs should develop and implement periodic reinforcement of infection control education. regular monitoring of infection control activities.