• Human Ecology Research
• /
• 제56권5호
• /
• pp.473-491
• /
• 2018

This study identifies Japanese study content on heat stroke prevention measures using clothes, provides basic data for quantitative wearing assessment studies, presents a developmental direction for those, and helps invigorate further research. Studies were collected concerning clothing-based heat stroke measures in order to analyze the following factors: current status of heat stroke by industry and working environment, heat stroke and body cooling method, clothing microclimate and air circulation in a hot environment, hot environments and wearable sensors, and heat stress reduction and skin exposure. The current WBGT standard does not consider the diversity of wearing clothes according to the working environment. Therefore, it is preferable to add a correction value in consideration of design, materials, and ventilation to prevent heat strokes. For the heat stroke and body cooling method, wearing water-perfused clothing is effective to reduce heat stress and maintain exercise ability. Changing the material and design of clothing or wearing air-conditioned clothing can improve ventilation and the clothing microclimate. However, further evaluation is needed on the effectiveness of air-conditioned clothing as a heat stroke prevention product. The measurement method using a wearable sensor can provide real-time data on the body response due to working in a hot environment. Therefore, it is an effective alarm for heat stroke. Skin exposure area and heat dissipation efficiency should be considered to prevent heat stroke. Reducing the covering area by exposing the head, neck, and limbs, and wearing breathable material can prevent heat stroke from increased body temperature.

• 한국산업보건학회지
• /
• 제28권4호
• /
• pp.393-405
• /
• 2018

Objective: This study examines the types of hazardous factors in the working environment and the time-trend for their exposure levels over 10 years (2007 to 2016). Study Design and Method: The types of hazardous factors and exposure levels were drawn from the 19 measurement reports on the working environment over 10 years at a shock absorber manufacturing facility. Risk assessment of the types of factors and time-trend of exposure levels were evaluated using the factors and exposure levels. Results: A total of 34 hazardous factors were evaluated. The types were noise, 15 organic compounds, seven kinds of acid sand alkalis, eight kinds of heavy metals, and three other compounds. Special management materials used were nickel, hexavalent chrome, and sulfuric acid. Human carcinogens (1A) used were trichloroethylene, nickel, and sulfuric acid. There were six types of substances belonging to the IARC's 2B (body carcinogens) classification or higher, including, methyl isobutyl ketone, ethyl benzene, and trichloroethylene. No detection was found for 627 out of the 2065 total measurements in 19 exposure survey reports, representing 30.4%. Organic solvents, acid and alkali products, and heavy metals showed continuous low exposure concentrations. Noise, welding fumes, and the evaluation of mixed solvents show a gradual decrease in geometric mean and maximum over the time-trend of 10 years. Conclusions: In the case of a shock absorber manufacturing facility, the hazardous factors of noise and the evaluation of mixed solvents still indicate high concentrations exceeding the exposure limits and necessitate reduction studies. These two factors and welding fumes showed a continuous decrease in their ten-year tendency. Organic compounds, acids/alkalis, and heavy metals were managed smoothly in a work environment of continuous low concentrations.

• 한국수소및신에너지학회논문집
• /
• 제24권3호
• /
• pp.264-274
• /
• 2013

Piping systems play an important role in gas and oil transferring system. In the piping system, there are many elements, such as valves and flow meters. In order to check their normal operating conditions, each signal from each element is displayed on the monitor in the pipe control room. By the way, there are several accidental cases in the piping system even if all signals from the local elements are judged to be normal on the monitor in the control room. Further, opposite cases often happen even the monitor shows abnormal while the local elements work normal. To overcome this abnormal functions, it is not so easy to construct the environment in which sensors detecting the working states of all elements installed in the piping system. In this paper, a new non-contact measurement technique which can calculate the elements' delicate displacements by using a PIV(particle image velocimetry) and diagnose their working states by using a neural network is proposed. The measurement system consists of a host computer, a micro system, a telescope and a high-resolution camera. As a preliminary test, the constructed measurement system was applied to measure delicate vibrations of mobile phones. For practical application, a pneumatic system was measured by the constructed system.

• 한국산업보건학회지
• /
• 제33권3호
• /
• pp.291-297
• /
• 2023

Objectives: An epidemiological investigation was requested for a worker who developed COPD and IPF after long-term molding and firing at a domestic tile manufacturing site. We would like to share the results of the exposure assessment and the estimation of past work. Methods: The content of crystalline silica in four raw materials was analyzed, and the respirable fraction of crystalline silica and dust generated in the air from molding and firing workers and other processes were measured. The measurement and analysis method referred to the NIOSH method. Results: The crystalline silica content of the raw material was 24~47%. The concentration of crystalline silica in the molding and firing process workers and the surrounding area was at the level of the exposure standards set by the Ministry of Employment and Labor and ACGIH, and the respirable and total dust exposure levels were generally low. The crystalline silica concentration of the area samples measured to estimate past work was about twice as high as the exposure standard of the Ministry of Employment and Labor (0.05 mg/m3), and the exposure levels of respirable dust were also quite high at 0.903 and 1.332 mg/m3. Conclusions: It was confirmed that tile molding and firing workers are currently exposed to a fairly high level of crystalline silica, and a high level is also confirmed in area samples to estimate past work. In the past, it is judged that the level of exposure would have been much higher due to differences in production volume, working method, presence/absence of local ventilation facilities, and process layout. When working in such a working environment for a long time, respiratory diseases such as lung cancer, COPD, and IPF can occur.

• 한국치위생학회지
• /
• 제18권4호
• /
• pp.501-513
• /
• 2018

Objectives: The purpose of this study was to investigate the perception of workplace bullying in the dental hygienists to use them as basic data for improving the organizational relationship of the dental hygienists. Methods: The subjects were 302 dental hygienists that had been working at the dental clinics and dental hospitals. These data were analyzed by SPSS Version 20.0 (IBM Co., Armonk, NY, USA). Factor analysis was used for exploratory and confirmatory data. Independent t-test and one-way ANOVA were used to find out mean differences for verbal violence, improper business, and improper work environment according to characteristics of subjects. Results: Upon the study results, there were statistically significant differences between the verbal violence and working patterns according to the mean differences of the subfactors on subject's characteristics. Also, there were statistically significant differences between the improper work environment and all of subject's characteristics. However, there was no statistically significant differences in the improper business. The factor analysis showed that the Workplace Bullying of the dental hygienists was composed of three elements, namely 'verbal violence', 'improper business,' and 'improper work environment.' The validity of the model examined by a confirmatory factor analysis satisfied most of the relevant requirements. The Cronbach's aplha shows a good reliability. Conclusions: In conclusion, it was proven that dental hygienist's Workplace Bullying measurement tool had high validity and reliability. Furthermore, this study can be used to improve dental hygienists' organizational relationship. Therefore, by identifying the recognition of the dental hygienists, this study can contribute to affect a positive influence in the dental hospitals.

• 한국지능시스템학회논문지
• /
• 제25권4호
• /
• pp.361-368
• /
• 2015

본 논문은 실내 환경에서 이동로봇의 위치추정을 위해 무향 칼만 필터(UKF, Unscented Kalman Filter)를 적용하는 방법을 기술한다. 위치 추정을 위해 적용한 무향 칼만 필터 방법은 측정 거리에 따라 오차 공분산 값을 조절하는 새로운 측정 불확실성 모델을 제안한다. 또한 이 방법은 속도정보의 불확실성 및 측정 불확실성에 관한 오차 공분산 행렬의 비 대각 성분을 '0'이 아닌 값으로 설정한다. 이 방법은 100*40m 의 실내 작업환경에서 외수용성 센서로서 레이저영역측정기(Laser range finder)를 가진 차륜형 이동로봇을 이용한 실험을 통하여 평가한다. 이 실험에서는 적응적 불확실성 모델을 사용하지 않는 보통의 방법과 제안된 방법의 추정성능을 비교한다. 또한 이 실험은 오차 공분산의 비 대각성분을 '0'이 아닌 값으로 설정하여 추정 성능이 개선되는 것을 확인한다. 이 논문은 이동로봇의 위치추정을 위한 실용적인 UKF 방법을 구현하고 그 성능을 평가 하는 것을 주요 내용으로 한다.

• 해양환경안전학회지
• /
• 제16권1호
• /
• pp.135-140
• /
• 2010

선박에서의 주요한 진동발생 원인으로는 주기관과 프로펠러에 의한 것이다. 이러한 가진원으로부터 발생한 진동은 선박에 탑재된 장비의 내구성에 악영향을 미치고, 선박의 승조원에게도 불쾌감 등의 나쁜 영향을 미치게 된다. 본 연구에서는 선박에서 발생하는 진동을 계측하지 위한 시스템을 구축하였고 실제 실습선의 거주공간에서 발생하는 진동을 계측하였으며, 계측된 진동을 바탕으로 ISO6954:2000E에 의거하여 거주성 평가를 행하였다.

• 제어로봇시스템학회논문지
• /
• 제22권2호
• /
• pp.89-96
• /
• 2016

This paper describes the design of a force measurement and communication system for the force measuring system in industrial robots. The force measurement and communication system is composed of a multi-axis force sensor and a controller for measuring the forces (x-direction force, y-direction force and z-direction force) and sending the measured forces to the robot's controller (PLC: Programmable Logic Controller). In this paper, the force measurement and communication system was designed and fabricated by using a DSP (Digital Signal Processor). An environment test and a grinding and deburring test using an industrial robot with the force measurement and communication system with three-axis force sensor were carried out to characterize the system. The tests showed that the system could safely measure the forces from the three-axis force sensor and send the measured forces to the industrial robot's controller while the grinding and deburring test was performed. Thus, it is thought that the fabricated force measurement and communication system could be used for controlling the force for an industrial robot's grinding and deburring.

• Journal of Information Processing Systems
• /
• 제2권2호
• /
• pp.101-106
• /
• 2006

Grid computing is an emerging technology that enables global resource sharing. In Korea, the $K^*$Grid provides an extremely powerful research environment to both industries and academia. As part of the $K^*$Grid project, we have constructed, together with the Korea Institute of Science and Technology Information and a number of domestic universities, a supercomputer Grid test bed which connects several types of supercomputers based on the globus toolkit. To achieve efficient networking in this Grid testbed, we propose a novel method of available bandwidth measurement, called Decoupled Capacity measurement with Initial Gap (DCIG), using packet trains. DCIG can improve the network efficiency by selecting the best path among several candidates. Simulation results show that DCIG outperforms previous work in terms of accuracy and the required measurement time. We also define a new XML schema for DCIG request/response based on the schema defined by the Global Grid Forum (GGF) Network Measurement Working Group (NM-WG).

• 대한간호학회지
• /
• 제14권2호
• /
• pp.28-37
• /
• 1984

The purpose of this study is to propose the baseline data for developing the stress measurement tool for staff nurses working in the hospital. Two hundred and fifteen stan nurses in Seoul National University Hospital were participated during the period from Feb. 28 to Mar. 10, 1984. Though the pretest and literature review a questionnaire was constructed with 63 stressors which were experienced by the nurses in the hospital. Subjects were given instruction to rate 1∼6 likert type scale according to the level of stress experienced by each stressor described. Reliability of the tool was tested by Cronbach's Alpha, and the result was α=0.94871. Factor analysis was applied to organize 63 items together. As the result, 15 factors were obtained and these factors explained 66.3% of variance. The 15 factors were: 1) Work overload 2) Role conflict as a profession 3) Lack of professional knowledge and skill 4) Interpersonal problem 5) Conflict in nurse doctor relationship 6) Work conflict with doctors 7) Emotional burden due to the limitation of medicine 8) Poor treatment 9) Unsatisfactory relationship with supervisor 10) Low reward 11) Unsatisfactory relationship with subordinate 12) Poor physical environment of unit 13）Responsibility for extra affairs 14）Unfamiliar situation 15）Night duty.