• Title/Summary/Keyword: Effective protection methods

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Protection Effects Associated with the Conditions for the Installations of SPDs (SPD의 설치조건이 보호효과에 미치는 영향)

  • Lee, Bok-Hee;Lee, Dong-Moon;Lee, Seung-Chil
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.20 no.2
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    • pp.60-67
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    • 2006
  • This paper presents the protection effect of surge protective devices(SPDs) according to the conditions of installations. To propose the effective protection measures of information and communication equipments against lightning surges, actual-sized experiments in relation to the protection effects on the positions of installations of SPDs, the length of branch circuit, the wiring methods, and the materials of conduit, were conducted. The effective method of protecting information and communication equipments from lightning surges is to install SPDs in the vicinity of input terminals of each electronic equipments to be protected. The wiring method of connecting an SPD minimizing the length of leads is desirable when point-to-point wiring is to be used.

Research Trends on the Treatment of Knee Osteoarthritis in Korean Medicine (퇴행성 슬관절염의 한의학적 치료에 관한 연구동향)

  • Yoh, Sang-Bum;Sul, Jae-Uk;Shin, Mi-Sook
    • Korean Journal of Acupuncture
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    • v.28 no.1
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    • pp.139-155
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    • 2011
  • Objectives : To research trends of studies on treatments of knee osteoarthritis in Korean medicine. Methods : Domestic theses, published from 2000 to 2010, mentioning the treatments of knee osteoarthritis in Korean medicine were reviewed and analyzed. This study researched 79 theses and classified again according to the fields of the treatment. Results : The results were obtained as below ; 1. Studies on pharmacoacupuncture account for 41% of the total (32cases/79cases). The target of treatments had changed from pain alleviation and anti-inflammation to cartilage-protection since 2006. 2. Herbal Drug, Bee Venom, Cervi Cornu Parvum pharmacoacupuncture, Taping Therapy and Tai-Chi Exercise program were more effective than others. Moreover research on exercise program such as Tai-Chi has been increasing. 3. Some Herbal Drug (Glycyrrhizae Radix, Angelicae Gigantis Radix, Achyrantis Radix, Paeoniae Radix, Eucommiae Cortex and so on) were mainly used to investigate the effect on cartilage protection, pain relief and anti-inflammation in laboratory test. 4. Acupuncture including individualized, local acupoints and constitution acupuncture were effective than others in pain alleviation and symptom relief. 5. Pharmacoacupuncture Bee Venom were effective in recovery of joint function and pain relief while Buthus martensii Karsch, Homnis Placenta and Cervi Cornu Parvum were effective in cartilage protection and recovery. 6. Moxibustion was efficient to reduce joint pain and partly increase ROM (range of motion) of knee joint, but was not efficient to recover the function of knee joint. Conclusions : These results indicate that research trends on knee osteoarthritis were changed from symptomatic treatment (pain alleviation and anti-inflammation) to conservative treatment (cartilage protection and recovery).

Effective Installation Methods of Down Conductors in Lightning Protection Systems (뇌보호시스템에서 인하도선의 효과적인 설치기법)

  • 이복희;엄주홍;이승칠;강성만
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.16 no.4
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    • pp.8-14
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    • 2002
  • A modern lightning protection system is required to eliminate the risks such as electrical shocks and damages of structures, electrical and electronic equipments due to lightning. However, the conventional lightning protection systems play and important role in protecting persons and structures only. Thus an effective lightning protection system is indispensable today in computer, information and communication facilities and etc. The mafor objective of this paper is to develop the technology to protect electronics and computerized facilities against lightning-caused overvoltages. The study is oriented on the control of the potential rise of down conductors with the type and installation method of down conductors. As a result, to reduce side flashes and hazards caused by the potential rise of down conductor due to lightning current, the coaxial cable with a low characteristic impedance and high insulation level is suitable for a down conductor. In particular it is extremely effective to bond down conductors to the steel supporter, metal raceways and steel frame of structures.

The awareness and performance towards the dental radiation protection behaviors in Busan and Gyeongnam (부산·경남 일부지역의 치과방사선 인식도와 수행도에 따른 치과방사선 방어행위)

  • Na, Hyeon-Hui;Jin, Hye-Jung;Lee, Min-Kyung
    • Journal of Korean society of Dental Hygiene
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    • v.14 no.5
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    • pp.673-680
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    • 2014
  • Objectives : The purpose of this study is to investigate the awareness and performance towards the dental radiation protection behaviors in dental institutions in Busan and Gyeongnam. Methods : Two hundred and one dental medical institutions in Busan and Gyeongnam participated in the survey from March 10 to April 4, 2014. The data were analyzed using SPSS 19.0 for ${\chi}^2$ test, t-test, ANOVA, and multiple regression analysis. Results : There were significant differences in the awareness and performance towards the radiation protection behaviors according to age, monthly income, and type of hospital(p<0.05). Protective equipment influenced on the awareness and performance of dental staff and patients(p<0.001). The important variables on dental radiation protection included protection facility and education of protective equipment. It is found the variable to affect the performance of dental radiation protection was protection facility, wearing of protective device staff and patients, education on RSM. Conclusions : These results can provide the basic data for the effective dental radiation safety management and improvement for the dental institutions.

A Protection Technique Against the Damages Caused by Lightning Surges on Information and Communication Facilities

  • Lee, Bok-Hee;Kang, Sung-Man;Ahn, Chang-Hwan
    • KIEE International Transactions on Electrophysics and Applications
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    • v.3C no.4
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    • pp.117-122
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    • 2003
  • The AC power lines and signal lines of info-communication networks are routed on overhead poles and are highly exposed to lightning strikes. Due to the potential difference between grounding points of AC power lines and signal lines, the electronic equipments connected to the signal lines can easily be damaged by lightning surges. In this work, in order to develop reliable methods of protecting information and communication facilities from lightning surges, the reliability and performance of SPDs (surge protective devices) were experimentally investigated in an actual-sized test circuit. The behaviors of SPDs against lightning surges from AC power lines and signal lines and the coordinated effects of SPD installation methods were evaluated. As a consequence, it was confirmed that the bypass arrester methods and common grounding system are both highly effective.

Natural dyeing of silk fabrics dyed with extracts of Thuja orientalis (측백 추출물을 이용한 견직물의 천연염색)

  • Kim, Sang Yool
    • The Research Journal of the Costume Culture
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    • v.21 no.5
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    • pp.699-707
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    • 2013
  • The natural dyeing of silk fabric with Thuja orientalis extract was investigated. The proper colorant concentration, dyeing temperature, dyeing time, and pH for the dyeing of silk fabric with Thuja orientalis extract were 100% v/v, $80^{\circ}C$, 80 minutes and pH 3, respectively. In various mordanted methods, the K/S values of mordanted methods were higher than those of unmordanted methods with increasing mordant concentration. Light colorfastness and washing colorfastness of Cu or Fe mordanted silk fabric was improved by mordanting. The antibacterial properties of dyed and mordanted silk fabric showed a high reduction rate, and Thuja orientalis extract was showed effective bacterial reduction. The dyed and mordanted fabric with Thuja orientalis extract showed a superior ultraviolet protection property.

Validation of a Model for Estimating Individual External Dose Based on Ambient Dose Equivalent and Life Patterns

  • Sato, Rina;Yoshimura, Kazuya;Sanada, Yukihisa;Sato, Tetsuro
    • Journal of Radiation Protection and Research
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    • v.47 no.2
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    • pp.77-85
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    • 2022
  • Background: After the Fukushima Daiichi Nuclear Power Station (FDNPS) accident, a model was developed to estimate the external exposure doses for residents who were expected to return to their homes after evacuation orders were lifted. However, the model's accuracy and uncertainties in parameters used to estimate external doses have not been evaluated. Materials and Methods: The model estimates effective doses based on the integrated ambient dose equivalent (H*(10)) and life patterns, considering a dose reduction factor to estimate the indoor H*(10) and a conversion factor from H*(10) to the effective dose. Because personal dose equivalent (Hp(10)) has been reported to agree well with the effective dose after the FDNPS accident, this study validates the model's accuracy by comparing the estimated effective doses with Hp(10). The Hp(10) and life pattern data were collected for 36 adult participants who lived or worked near the FDNPS in 2019. Results and Discussion: The estimated effective doses correlated significantly with Hp(10); however, the estimated effective doses were lower than Hp(10) for indoor sites. A comparison with the measured indoor H*(10) showed that the estimated indoor H*(10) was not underestimated. However, the Hp(10) to H*(10) ratio indoors, which corresponds to the practical conversion factor from H*(10) to the effective dose, was significantly larger than the same ratio outdoors, meaning that the conversion factor of 0.6 is not appropriate for indoors due to the changes in irradiation geometry and gamma spectra. This could have led to a lower effective dose than Hp(10). Conclusion: The estimated effective doses correlated significantly with Hp(10), demonstrating the model's applicability for effective dose estimation. However, the lower value of the effective dose indoors could be because the conversion factor did not reflect the actual environment.

A Review of Organ Dose Calculation Tools for Patients Undergoing Computed Tomography Scans

  • Lee, Choonsik
    • Journal of Radiation Protection and Research
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    • v.46 no.4
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    • pp.151-159
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    • 2021
  • Background: Computed tomography (CT) is one of the crucial diagnostic tools in modern medicine. However, careful monitoring of radiation dose for CT patients is essential since the procedure involves ionizing radiation, a known carcinogen. Materials and Methods: The most desirable CT dose descriptor for risk analysis is the organ absorbed dose. A variety of CT organ dose calculators currently available were reviewed in this article. Results and Discussion: Key common elements included in CT dose calculators were discussed and compared, such as computational human phantoms, CT scanner models, organ dose database, effective dose calculation methods, tube current modulation modeling, and user interface platforms. Conclusion: It is envisioned that more research needs to be conducted to more accurately map CT coverage on computational human phantoms, to automatically segment organs and tissues for patient-specific dose calculations, and to accurately estimate radiation dose in the cone beam computed tomography process during image-guided radiation therapy.

A Study on the construction of physical security system by using security design (보안디자인을 활용한 시설보안시스템 구축 방안)

  • Choi, Sun-Tae
    • Korean Security Journal
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    • no.27
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    • pp.129-159
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    • 2011
  • Physical security has always been an extremely important facet within the security arena. A comprehensive security plan consists of three components of physical security, personal security and information security. These elements are interrelated and may exist in varying degrees defending on the type of enterprise or facility being protected. The physical security component of a comprehensive security program is usually composed of policies and procedures, personal, barriers, equipment and records. Human beings kept restless struggle to preserve their and tribal lives. However, humans in prehistoric ages did not learn how to build strong house and how to fortify their residence, so they relied on their protection to the nature and use caves as protection and refuge in cold days. Through the history of man, human has been establishing various protection methods to protect himself and his tribe's life and assets. Physical security methods are set in the base of these security methods. Those caves that primitive men resided was rounded with rock wall except entrance, so safety was guaranteed especially by protection for tribes in all directions. The Great Wall of China that is considered as the longest building in the history was built over one hundred years from about B.C. 400 to prevent the invasion of northern tribes, but this wall enhanced its protection function to small invasions only, and Mongolian army captured the most part of China across this wall by about 1200 A.D. European lords in the Middle Ages built a moat by digging around of castle or reinforced around of the castle by making bascule bridge, and provided these protections to the resident and received agricultural products cultivated. Edwin Holmes of USA in 20 centuries started to provide innovative electric alarm service to the development of the security industry in USA. This is the first of today's electrical security system, and with developments, the security system that combined various electrical security system to the relevant facilities takes charging most parts of today's security market. Like above, humankind established various protection methods to keep life in the beginning and its development continues. Today, modern people installed CCTV to the most facilities all over the country to cope with various social pathological phenomenon and to protect life and assets, so daily life of people are protected and observed. Most of these physical security systems are installed to guarantee our safety but we pay all expenses for these also. Therefore, establishing effective physical security system is very important and urgent problem. On this study, it is suggested methods of establishing effective physical security system by using system integration on the principle of security design about effective security system's effective establishing method of physical security system that is increasing rapidly by needs of modern society.

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REffects of Surge Protective Devices with Respect to Types of System Grounding and Wiring Methods (전원계통의 접지방식 및 배선방식에 따른 서지보호기의 효과)

  • 이수봉;이복희;길형준
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.18 no.2
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    • pp.90-99
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    • 2004
  • High speed info-communications equipment are required with development of highly information-oriented society, the intelligent industrial facilities and social systems such as administrative, financial and traffic systems, are gradually becoming to automation, which are composed of the integrated circuits and micro-semiconductors, remote control and operation. Thus modern micro-electronic circuits can frequently be damaged by lightning surge. The protection of electronic circuits from lightning overvoltages is concentrated very interesting. In this paper, for the purpose of providing the effective protection method of electronic devices such micro-computers from lightning surges in a residential building, the protection effect of surge protective devices according to types of system groundings were experimentally analyzed. Also the effective installation method of surge protective devices was examined and proposed. The installation of SPDs in retrofits was a high remnant voltage across the protected device owing to the inductance in the long wires to the SPDs. Finally the method of installing the SPD by twisted pain wires is remarkably effective for fast rising transient overvoltages.