• 환경위생공학
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• 제15권4호
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• pp.1-3
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• 2000

Indoor carbon monoxide (CO) concentration and personal CO exposures were measured Asan where CO poisoning from twenty coal usage briquette as a domestic fuel to cook and space heating. Twenty-five were houses selected from the Asan area for the survey conducted in February 1997. Newly developed passive CO samplers were placed in the kitchen and living room for the indoor concentration measurement and were worn by homemakers for personal exposure monitoring. The daily average of indoor CO concentration was 16ppm in the kitchen and 10ppm in the living room. The indoor concentration and personal exposures to CO were different in types of the space heating system. House ventilating methods and socioeconomic conditions were also important factors in determining the indoor and personal CO level in Asan.

• 한국대기환경학회지
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• 제6권1호
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• pp.97-102
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• 1990

A pilot field study was conducted to measure indoor and personal exposure to carbon monoxide (CO) levels using personal monitors from January to February in 1989. The principal objectives of the study was to design and evaluate the research protocol and the instrumentation performance for application to the conduct of a large-scale personal monitoring program. The mean CO concentrations in kitchen and in bedroom were 23.4 and 11.9 ppm, respectively, while mean concentration of personal CO exposure was 18.9 ppm. It was found that the mean CO concentrations in kitchen exceeded 20 ppm of the Korea ambient CO standard(8-hr average) not to be exceeded more than three times per year. The results suggest that indoor CO levels in Korean houses appear to be affected by use of coal briquette for heating any cooking.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.9-12
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• 2005

In this paper. we offer a new monitoring system that controls all of the windfar. it can also apply use general wind turbine systems and real meteorological tower. We propose a hierarchical releiable monitoring system connected by wireless communication channels between monitoring host computer and modular slave measuring subsystems. Our system has two hierarchical subsystems: slave measuring systems, and supervisory host computer. We design and implement that the slave measuring subsystems is placed in meteorological tower and wind turbines, and the supervisory host computer in safety zone, The micro-controller in slave measuring system is duplicated using cold-standby method for reliability. The host computer and slave system constructs a feedback system, with wireless communication channel between them. For monitoring and command function, the supervisory computer is implemented with a Personal Computer using graphic user interface. Consequently. we can get a reliable but economic system.

• Journal of Radiation Protection and Research
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• 제22권2호
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• pp.85-95
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• 1997

전통적으로 개인방사선감시에 열형광선량계와 필름배지가 공식개인선량계로 이용되어 왔고 현재까지도 여전히 가장 보편적으로 사용되고 있지만, 최근에는 Si 다이오드와 G-M관을 이용한 능동형 전자개인선량계가 개발 보급되고 있다. 전자개인선량계는 누적선량을 곧바로 알 수 있다는 분명한 장점을 가지고 있을 뿐만 아니라 선량률에 관한 정보도 제공하므로 높은 비용부담에도 불구하고 피폭관리의 용이함으로 인해 주목을 받고 있다. 이에 세 종류의 전자개인선량계 즉, EPD2, STEPHEN6000, PD-3i에 대하여 재현성, 정확성, 선형성, 에너지와 방향 의존성, 반응시간을 포함하는 선량계의 전반적인 성능을 실험적으로 평가한 후 판단기준으로 IEC standard 그리고 Ontario Hydro standard와 비교함으로써 전자개인선량계가 방사선방호의 핵심인 개인선량측정에 충분한 신뢰도를 제공하여 공식선량계로 적합한가를 논의하였다. STEPHEN6000 및 PD-3i는 표층선량 측정능력의 보완이 필요하였다.

• 센서학회지
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• 제27권5호
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• pp.340-344
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• 2018

Electrodes are an important part of electrocardiography (ECG); disposable electrodes have been extensively used. However, personal ECG monitoring devices for Internet of Things applications require reusable electrodes. As there have been no systematic studies on the characteristics of reusable electrodes to date, we conducted this study to assess the performance and feasibility of electrodes with different materials. We built reusable electrodes using twelve different metallic materials, including commonly used copper, silver, zinc, plating materials, chemically inert titanium, stainless steel, and aluminum. Each electrode was fabricated to a size of $5{\times}10mm$. Their characteristics such as offset, baseline drift, stabilization time, and chemical inertness were compared. A personal ECG monitoring system was used to test the manufactured electrodes. The performances of the Ag, Cu, and Zn electrodes were better than the performances of other electrodes. However, these materials may not be used owing to the chemical changes that occur when the electrodes are in contact with the skin, such as discoloration and corrosion, which deteriorate their electrical characteristics. Titanium, stainless steel, and aluminum are chemically stable. The titanium electrode showed the best performance among the three, and it is our recommendation as a material for manufacturing reusable electrodes.

• Environmental Analysis Health and Toxicology
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• 제15권3호
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• pp.81-91
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• 2000

Residents who live near petrochemical industrial areas are exposed to a variety of petrochemicals, including benzene or benzene-containing liquids. It is a serious concern because some VOCs are carcinogens naturally present in petroleum and gasoline. The aim of this study was to assess the exposure to VOCs, measured by personal/indoor/outdoor air sampling, and to estimate the relationship between the air samples and biological monitoring data. Through biological monitoring, we investigated VOCs in blood and s-phenylmercapturic acid (s-PMA) , minor urinary metabolites of benzene. The external benzene exposure of subjects was measured using passive dosimeters and urinary s-PMA and blood-benzene were determined by GC/MS. More than 80% of subjects were detected for m-xylene, ethylbenzene, and toluene in blood samples and not detected at all for chloroform, 1 , 1 , 1 -trichloroethylene, and tetrachloroethylene. The mean concentration of benzene in the breathing zone of residents was 6.3 $\mu\textrm{g}$/m$^3$, personal, indoor and outdoor concentrations were strongly correlated to each other. s-PMA detected in all subject samples was affected by personal exposure (p< 0.05) and the level was different by age (p< 0.01). Blood benzene was not affected by external benzene during these periods .

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.313-316
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• 2015

Construction is one of the most dangerous job sectors, which reports tens of thousands of time-loss injuries and deaths every year. These disasters incur delays and additional costs to the projects. The safety management needs to be on the top primary tasks throughout the construction to avoid fatal accidents and to foster safe working environments. One of the safety regulations that are frequently violated is the wearing of personal protection equipment (PPE). In order to facilitate monitoring of the compliance of the PPE wearing regulations, this paper proposes a vision based method that automatically identifies whether workers wear hard hats and safety vests. The method involves three modules - human body detection, identification of safety vest wearing, and hard hat detection. First, human bodies are detected in the video frames captured by real-time on-site construction cameras. The detected human bodies are classified into with/without wearing safety vests based on the color features of their upper parts. Finally, hard hats are detected on the nearby regions of the detected human bodies and the locations of the detected hard hats and human bodies are correlated to reveal their corresponding matches. In this way, the proposed method provides any appearance of the workers without wearing hard hats or safety vests. The method has been tested on onsite videos and the results signify its potential to facilitate site safety monitoring.

• ETRI Journal
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• 제28권4호
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• pp.537-540
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• 2006

When multiple ZigBee wireless personal area networks (WPANs) are in close proximity to each other, contentions and collisions in transmissions will lead to increased packet delays. However, there is no existing study on how delay performance would be affected in a crowded real-life environment where each person walking down a busy street would be wearing a ZigBee WPAN. This letter studies the use of ZigBee WPANs in such a real-life environment for real-time heart beat monitoring. To be pragmatic, we derived a mobility pattern from the analysis of a real-life video trace. Then, we estimated the delay performance from the video trace by combining data collected from ZigBee experiments. The results show that the 300 ms packet delay requirement will not be met for only 11% of the time. When failure occurs, it will last for an average duration of 1.4 s.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1991년도 추계학술대회
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• pp.79-82
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• 1991

Digital FHR monitoring system based on the personal computer combined wi th the digital signal processing (DSP) board was implemented. The DSP board acquires and digitally processes ultrasound fetal Doppler signal for digital rectification, envelope detection, autocorrealtion function calculation and its peak position detection. The personal computer interfaced with the DSP board is in charge of graphic display, hardcopy, data taransmission and on-line analysis of fetal heart rate change including on-line warning system, base-line estmation, acceleration, deceleration and variability. The advantages of PC-DSP based system can be summarized as follows: 1) Minimum hardware realization. 2) Increased flexibility. 3) Total care system.

• 한국의류학회지
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• 제20권5호
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• pp.738-752
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• 1996

The purposes of this study were 1) to test the interactive effects of usage-situation (wedding receptions, home, and vacation) and personal characteristics (age, income, education, job or self-monitoring) on clothing benefits sought and 2) to identify brand type preference of consumer groups segmented by age, income, education, job or self-monitoring within a situation. The data were collected via a questionnaire from 601 housewives of ages 20's∼ 50's living in Seoul, Korea. The data were analyzed by factor analysis, repeated measure two-way ANOVA and Chi-square test. The results of this study were as follows. First, by repeated measure tow-way ANOVA, there were significant interactions of age and situation, and interactions of education and situation on Youth/Fashion benefits and Brand-value benefits. And interactive effects of education and situation on Self-expression benefits and Economic-value benefits were significant by repeated measure two-way A NOVA. Second, based on x2-test, brand type preference was significant difference between consumer groups segmented by age, education and job within a situation. And preferences of brand type were different among usage situations.