Hearing Threshold Shift and Speech Intelligibility Index of Personal Hearing Protective Devices

최철희 한국청각언어재활학회 2013 Audiology and Speech Research Vol.9 No.1

The objective of this study is to investigate the effectiveness of the personal hearing protective devices in terms of the hearing threshold shift and the speech intelligibility index. The hearing threshold shift was used to quantify the protection effect of the personal hearing protective devices and obtained by subtracting the baseline threshold measured without the personal hearing protective devices from the hearing threshold measured with the personal hearing protective devices. The speech intelligibility index (SII) was used to predict and compare the potential benefits of each personal hearing protective device and obtained from the count-the dots method. A total of 6 college students aging from 21 to 25 years old were randomly recruited as subjects. Different types of personal hearing protective devices (earplug and earmuff) were used in this study. A statistically significant difference between the mean amount of threshold shift at low frequency (0.25-1 kHz) and that of high frequency region (2-8 kHz) was observed. The personal hearing protective devices (earplug and earmuff) were effective in protecting hearing from high frequency noises than low frequency noises. The use of earmuff was effective at the low frequency region while the use of earplug was effective at the high frequency region. In addition, the use of the earplug was more effective for the SII than that of the earmuff. The protection amount of the personal hearing protective devices (earplug and earmuff) ranged from 23 to 38 dB. However, the SII ranged from 32.6 to 54.5%, which indicates that the subjects misunderstood or missed the speech information ranged from 45.5 to 67.4% as mild to moderate hearing loss. This may lead to the development of new personal hearing protective devices which are effective for protecting hearing and understanding speech.

저전압 전원용 서지보호장치 철도 규격의 개선방안

정용철,김언석,이재호,조봉관,김재철 한국조명전기설비학회 2002 조명·전기설비학회논문지 Vol.16 No.2

본 논문에서는 철도 시스템에서 사용하는 저압 전원용 서지보호장치(surge protective devices) 규칙의 성능평가 항목 및 성능개선 방안에 대하여 고찰하였다. 먼저 철도시스템 환경과 관련된 전자기장해(electromagnetic interference) 현상을 검토하였다. 그리고 국제규격인 IEC 및 IEEE와 평가항목 및 펑가방법 등을 비교 검토하였다. 검토 결과 국내 철도관련 규격은 국제규격과 비교하여 비교하여 발견하였다. 개선방안으로 서지 보호소자 단위의 시험은 삭제하고, 규격 종류는 전원용과 신호용으로 분리하며, 서지 파형은 국제적으로 인정된 것을 사용하도록 제안하였다. 철도용 저압 서지보호장치에 대해 서지제한전압 측정 및 서지 수명시험을 국제규격에 따라 시험한 결과 만족스러운 결과를 얻었다. In this paper we study the performance test items and improvement plans of surge protective devices for low-voltage power circuits used in railway system. Above of all, the sources of electromagnetic interference in railway system are researched. And then we compared domestic railway standard with IEC and IEEE standards far the test items and methodologies of surge protective devices. Through the investigations, we found that the domestic standard is behind in the number of test items and methods on surge protective devices. As the countermeasures, we suggest removing component tests of surge protective devices, separating standards for power and signal standards, and using international surge waveform. In applying to domestic railway surge protective devices, surge limiting voltage measuring and surge endurance tests by international standard methods are good result.

허베이스피릿호 유류유출사고 방제작업 참여자의 보호장비착용 효과

이승민,하미나,김은정,정우철,허종일,박석건,권호장,홍윤철,하은희,이종성,정봉철,이정애,임호섭,최예용,조용민,정해관,Lee, Seung-Min,Ha, Mi-Na,Kim, Eun-Jung,Jeong, Woo-Chul,Hur, Jong-Il,Park, Seok-Gun,Kwon, Ho-Jang,Hong, Yun-Chul,Ha, Eun-Hee,Lee, Jong-Se 대한예방의학회 2009 예방의학회지 Vol.42 No.2

Objectives : To assess the protective effects of wearing protective devices among the residents and volunteers who participated in the cleanup of the Hebei Spirit oil spill. Methods : A total of 288 residents and 724 volunteers were surveyed about symptoms, whether they were wearing protective devices and potential confounding variables. The questionnaires were administered from the second to the sixth week following the accident. Spot urine samples were collected and analyzed for metabolites of 4 volatile organic compounds(VOCs), 2 polycyclic aromatic hydrocarbons(PAHs), and 6 heavy metals. The association between the wearing of protective devices and various symptoms was assessed using a multiple logistic regression adjusted for confounding variables. A multiple generalized linear regression model adjusted for the covariates was used to test for a difference in least-square mean concentration of urinary biomarkers between residents who wore protective devices and those who did not. Results : Thirty nine to 98% of the residents and 62-98% of volunteers wore protective devices. Levels of fatigue and fever were higher among residents not wearing masks than among those who did wear masks(odds ratio 4.5; 95% confidence interval 1.23-19.86). Urinary mercury levels were found to be significantly higher among residents not wearing work clothes or boots(p<0.05). Conclusions : Because the survey was not performed during the initial high-exposure period, no significant difference was found in metabolite levels between people who wore protective devices and those who did not, except for mercury, whose biological half-life is more than 6 weeks.

트랜스휴머니즘 시대 이식형 의료기기의법적 위험에 대한 연구 - 개인정보보호와 사이버정보보안을 중심으로 -

김성용,정관영 고려대학교 법학연구원 2022 고려법학 Vol.- No.105

이 글은 예상하기 어려울 정도로 빠르게 발전하는 과학기술로부터 비롯된 이른바 트랜스휴머니즘 시대에 접어들게 되면서, 이를 실현할 수단인 이식형 의료기기가 내포하고 있는 개인정보 및 정보보안의 법적 위험에 초점을 맞추었다. 따라서 아직은 현실에서 일어나지 않았거나, 어쩌면 일어날 것 같지 않아서 다소 생소한 느낌이 드는 글로 비춰 질 수 있다. 그럼에도 불구하고 이런 생소한 느낌은 점차 현실화 되어 가고 있다. 다름 아닌 공상과학 영화에서 인간의 신체는 현실과 상상의 경계에서 다양한 가능성으로 비춰지고 있듯, 이제는 현실에서도 실현불가능하게 보였던 일들을 보고, 느끼고 경험하는 시대가 펼쳐지고 있다. 아직은 희박한 가능성이라고 하지만 첨단과학기술은 인간의 유한한 생물학적 조건을 기계와의 흡수․통합으로 탈신체화를 추구하고자 하는 트랜스휴머니즘 사고(思考)에 기여하였다. 그리고 이러한 트랜스휴머니즘적 사고가 현실화될 수 있도록 기여한 이식형 심장 제세동기(implantable cardioverter defibrillators ; ICDs), (체내)이식형 달팽이관(Cochlear Implants), 컴퓨터 의족(의수)(Foot Drop Implants)과 같은 인체 이식형 의료기기는 이상적인 트랜스휴머니즘의 중심에 서게 됐다. 결과적으로 이식형 의료기기는 신체장애로 고통 받는 이들에게 한줄기 희망을 선사하며 인간친화적인 트랜스휴머니즘이 의미하는 것이 무엇인지에 대한 방향을 제시해 주었다. 그렇다면 인간과 기계와의 흡수․통합으로 이상적인 트랜스휴머니즘의 실현 수단으로써 중요한 위치에 있는 이식형 의료기기 수혜자, 즉 이를 이식받은 인간을 어떻게 정의해야 할까? 트랜스휴먼은 자연적·생물학적 존재인 인간과 포스트휴먼으로 알려진 인공지능 사이의 경계쯤으로 정의되고 있는바, 이식형 의료기기를 삽입한 인간이 인간에 가까운 트랜스휴먼인 것인지 아니면 트랜스휴먼에 가까운 인간인 것인지 궁금하다. 아울러 이런 의문으로부터 이식형 의료기기를 이식받은 자는 개인정보보호법상 정보주체로서 보호받을 수 있는 것인지 역시 궁금하다. 앞으로 이식형 의료기기를 이식받게 되는 경우가 점차 증가할 것으로 예상되는 가운데, 지금처럼 한 두 개의 기기를 이식한 경우 외에도, 신체의 1/3, 1/2 또는 신체 대부분을 이식형 의료기기를 내재하고 있는 경우에는 자연적·생물학적 존재가 아닌 새로운 인간 존재로 바라보게 될 가능성은 없는 것인지 의문이다. 바로 모두가 당연하게 생각하는 인간의 개념과 다가올 미래사회의 전혀 새로운 인간의 개념을 논하는 것은 이상적인 트랜스휴머니즘 실현의 수단인 이식형 의료기기가 내포하고 있는 법적 위험을 해결하기 위한 출발점이라고 할 것이다. 현행 개인정보보호법 제2조 제3호에서 밝히고 있는 ‘사람(인간)’에 대한 개념이 정립되지 않는다면 현행법만으로는 이식형 의료기기를 이식받은 자에 대한 정보주체의 법적 권리를 보장할 수 없게 되어 이들의 법적 불안은 계속될 수밖에 없다. 이식형 의료기기는 유무선통신기능이 가능한 디지털 전자기기로 데이터를 생성하고 외부와 송수신이 가능하다. 따라서 환자의 치료 설정 등 많은 개인정보를 포함하고 있는 이식형 의료기기는 데이터의 무결성에 대한 악의적인 변경이 일어날 수 있고, 데이터 기록 및 전송과정에서 환자 정보와 프라이버시를 침해하는 악의적인 공격에 취약하다는 문제를 갖고 있다. 인... As we enter the so-called transhumanism era which stems from unpredictably fast-developing science and technology, this article focuses on the legal risks of personal data and data security of implantable medical devices by means of realizing it. Therefore, it may be seen unrealistic or felt somewhat unfamiliar. As we have seen in science fiction movies, the human body is seen as various possibilities in the boundary between reality and imagination. Although it is still a rare possibility, high-tech technology has contributed to the transhumanistic thinking of pursuing de-bodyization by absorbing and integrating human finite biological conditions with machines. And implantable medical devices such as implantable cardioverter defibrillators(ICDs), cochlear implants and computer prosthetics that helped make this transhuman thinking a reality have become at the center of ideal transhumanism. As a result, the implantable device gave a ray of hope to those suffering from physical disabilities and provided a direction for what ideal transhumanism is. If so, how we define the recipients of implantable medical devices who hold an important position as means of realizing transhumanism through absorption and integration of humans and machines? Transhuman is defined as the boundary between humans, which are natural and biological beings, and posthuman, known as artificial intelligence, so I wonder if the human who inserted the implantable medical device is a transhuman close to a human or a transhuman close to a transhuman. In addition, it is curious whether a person who has received a transplant type medical device can be protected as an data subject under the Personal Data Protection Act. With implantable medical devices expected to increase in the future, it is questionable whether those who 1/3 or 1/2 of the body, or most of the body consist of implantable medical devices will be viewed as a new human being rather than a natural or biological one. Discussing the human concept that everyone takes for granted and the completely new human concept in the future society is a starting point for solving the legal risks of implantable medical devices, which are an ideal means of realizing transhumanism. If a new concept of humans is not established within the scope of interpretation of Article 2, No. 3 "People(Human being)" of the current Personal Data Protection Act, legal anxiety over beneficiaries embedded with implantable medical devices under the current law will continue. Implantable Medical Devices are digital electronic devices that can perform wired and wireless communication functions and can generate data and transmit and receive data from the outside. Thus, implantable medical devices, which contain a lot of personal data, such as setting up patient care, are vulnerable to malicious attacks that violate patient data and privacy during data recording and transmission. As transhumanism and implantable devices which are human aspirations cannot be separated, legal risks such as personal data protection and cyber data security are bound to coexist in the process of realizing ideal transhumanism. The scope of interpretation of Article 2 No. 3 "People(Human being)" of the personal data protection and the security risk under Article 28-2 of the same Act can be said to be the legal risk of implantable medical devices in the process of realizing transhumanism.

Optimal Operation Methods of Protection Devices in Distribution Systems with PV Systems

Byung-Ki Kim,Dae-Seok Rho 한국산학기술학회 2014 SmartCR Vol.4 No.6

This paper deals with the technical problems of protection devices in distribution systems with connected photovoltaic systems by developing a test device of protection coordination for photovoltaic systems. In order to analyze the operational characteristics of the protection devices in a distribution system connected with photovoltaic systems, in which bi-directional power flow could be supplied, this paper develops a test device that is composed of a model distribution system, protection device, and model PV system. By performing a simulation for operational characteristics of the protection devices based on the test device, this paper proposes a malfunction mechanism for the protection devices. The simulation results show that this paper is practical and effective for the technical guideline for the PV systems.

군사용 레이더 시스템 보호를 위한 낙뢰서지 방호장치의 설계

안창환 대한전자공학회 2023 전자공학회논문지 Vol.60 No.10

본 논문은 군사용 레이더 시스템에 적용되는 인버터의 출력단에 설치되어 낙뢰로 부터 인버터와 레이더 시스템을 보호하기 위한 새로운 서지 방호장치를 제안한다. 일반적으로 저압 배전계통에 사용되는 인버터는 입력측에 서지방호장치가 설치되어 있으나, 군사용 레이더 시스템에서는 인버터와 전동기가 물리적으로 떨어져 있기 때문에 구조물에 뇌격이 침입하면 인버터와 전동기에 연결된 케이블이 낙뢰전류의 유도 영향을 받게 된다. 따라서 이러한 구조적인 특성으로 인해 출력단에도 서지 방호장치가 필요하다. 또한, 저압 배전계통의 전원 주파수는 60Hz이지만, 인버터의 출력주파수는 PWM(Pulse Width Modulation) 제어를 통해 수 kHz로 출력된다. 따라서 인버터의 출력주파수는 서지 방호장치를 설계하고 적용하는데 반드시 고려해야 할 중요한 요소 중 하나이다. 본 연구에서는 이러한 고주파 환경에서 효과적으로 동작할 수 있는 새로운 서지 방호장치를 설계하고 잔류전압과 누설전류에 대한 동작 특성을 분석하였다. 본 연구의 결과는 유사한 조건에서 서지 방호장치를 설계하거나 선택할 때 유용한 정보를 제공할 것으로 기대된다. This paper proposes a new surge protective device that is installed at the output side of an inverter applied to military radar systems to protect the inverter and radar system from lightning strikes. Generally, inverters used in low-voltage distribution systems is installed surge protective devices on the input side, but military radar systems, the inverter and motor are physically separated. When a lightning strike invades the structure, the cables connected to the inverter and motor are influenced by the induced effects of lightning currents. Consequently, due to these structural characteristics, surge protective devices are also required at the output side. Additionally, while the power frequency of low-voltage distribution systems is 60Hz, the output frequency of the inverter is in the range of several kHz due to Pulse Width Modulation (PWM) control. Thus, the output frequency of the inverter is one of the crucial factors to consider when designing and implementing surge protective devices. In this study, we designed new surge protective devices capable of effectively operating under such high-frequency environment and analyzed their operational characteristics such as residual voltage and leakage current. The results of this study are expected to provide valuable information for designing and selecting surge protective devices under similar conditions.

An Accurate Model of Multi-Type Overcurrent Protective Devices Using Eigensystem Realization Algorithm and Practice Applications

Cheng, Chao-Yuan,Wu, Feng-Jih The Korean Institute of Electrical Engineers 2016 Journal of Electrical Engineering & Technology Vol.11 No.1

Accurate models of the characteristics of typical inverse-time overcurrent (OC) protective devices play an important role in the protective coordination schemes. This paper presents a novel approach to determine the OC protective device parameters. The approach is based on the Eigensystem Realization Algorithm which generates a state space model to fit the characteristics of OC protective devices. Instead of the conventional characteristic curves, the dynamic state space model gives a more exact fit of the OC protective device characteristics. This paper demonstrates the feasibility of decomposing the characteristic curve into smooth components and oscillation components. 19 characteristic curves from 13 typical and 6 non-typical OC protective devices are chosen for curve-fitting. The numbers of fitting components required are determined by the maximum absolute values of errors for the fitted equation. All fitted equations are replaced by a versatile equation for the characteristics of OC protective devices which represents the characteristic model of a novel flexible OC relay, which in turn may be applied to improve the OC coordination problems in the sub-transmission and distribution systems.

An Accurate Model of Multi-Type Overcurrent Protective Devices Using Eigensystem Realization Algorithm and Practice Applications

Chao-Yuan Cheng,Feng-Jih Wu 대한전기학회 2016 Journal of Electrical Engineering & Technology Vol.11 No.1

Accurate models of the characteristics of typical inverse-time overcurrent (OC) protective devices play an important role in the protective coordination schemes. This paper presents a novel approach to determine the OC protective device parameters. The approach is based on the Eigensystem Realization Algorithm which generates a state space model to fit the characteristics of OC protective devices. Instead of the conventional characteristic curves, the dynamic state space model gives a more exact fit of the OC protective device characteristics. This paper demonstrates the feasibility of decomposing the characteristic curve into smooth components and oscillation components. 19 characteristic curves from 13 typical and 6 non-typical OC protective devices are chosen for curvefitting. The numbers of fitting components required are determined by the maximum absolute values of errors for the fitted equation. All fitted equations are replaced by a versatile equation for the characteristics of OC protective devices which represents the characteristic model of a novel flexible OC relay, which in turn may be applied to improve the OC coordination problems in the subtransmission and distribution systems.

±35kV급 MVDC 실증 배전망의 보호협조기기 운용알고리즘에 관한 연구

이후동(Hu-Dong Lee),한병길(Byeong-Gill Han),김지명(Ji-Myung Kim),김윤호(Yun-Ho Kim),노대석(Dae-Seok Rho) 한국산학기술학회 2023 한국산학기술학회논문지 Vol.24 No.5

최근, 기존 AC 배전선로의 선로용량을 증대시키기 위하여 MVDC 배전망에 대한 실증 연구가 활발하게 진행되고 있다. 그러나, 전력변환 핵심 설비인 MVDC 배전 스테이션에 대한 구체적인 운용 기준이 마련되어 있지 않아, 보호기기 정정 등의 운영방안이 요구되고 있다. 특히, MVDC 배전 스테이션 연계 시 배전계통측 보호기기와의 협조를 고려하지 않고 운용하는 경우, 사고발생 시 고장 구간이 파급되어 동일선로의 타 고객에게 악영향을 줄 가능성이 있다. 따라서, 본 논문에서는 ±35kV MVDC 실증 배전망 대상으로 계통측 보호기기와의 원활한 보호협조 수행을 위하여, MVDC 배전 스테이션용 보호협조기기에 대한 사고유형 및 시나리오별 운용알고리즘을 제안한다. 또한, 배전계통 상용해석 프로그램인 PSCAD/EMTDC를 이용하여, 배전용변전소, MVDC 스테이션 등으로 구성된 ±35kV MVDC 실증 배전망의 모델링을 수행한다. 제안한 보호협조기기 운용알고리즘과 다양한 상정사고를 바탕으로 MVDC 실증 배전망의 보호협조 운용특성을 평가한 결과, 리클로저 정정 방식을 이용하여 MVDC 배전 스테이션용 보호협조기기를 운용하면, 최소 38.7cycles 이상의 협조시간차가 확보되어 보호협조 기준치인 17 cycles을 만족하므로, 본 논문에서 제안한 보호협조 기기의 운용알고리즘이 MVDC 실증 배전망의 보호협조에 유용함을 확인하였다. Recently, demonstration projects on an MVDC distribution network have been actively carried out to increase the capacity of an existing AC distribution system. However, since there are no specific protection guidelines for an MVDC station, which is a key facility for power conversion, operation methods of protection devices are required. In particular, if an MVDC station is operated without considering the coordination of protection devices in a distribution substation, customers in the same distribution line may be adversely affected by a fault section expanding when a fault occurs. Therefore, this paper proposes an operation algorithm for protection coordination of protection devices in an MVDC station by taking into account fault types and scenarios in order to properly operate protection devices in a ±35-kV MVDC distribution system. We also modeled a ±35-kV MVDC demonstration system by using PSCAD/EMTDC S/W. It was composed of a distribution substation, MVDC station, and protection devices. The evaluation results of operation characteristics for protection devices based on the proposed algorithm and various fault scenarios confirmed that the proposed algorithm is a useful method to operate protection devices in an MVDC station because 38.7 cycles of the coordination time interval is satisfied by securing 17 cycles as technical guide.

태양광전원의 연계에 의한 배전계통 보호기기의 최적 운용방안에 관한 연구

김병기(Byeon-Gi KIM),박재범(Jae-Beom Park),유경상(Kyeong-Sang You),노대석(Dae-Seok Rho) 대한전기학회 2011 전기학회논문지 Vol.60 No.8

This paper deals with the technical problems for the protection devices, by simulating test facilities of protection coordination for Photovoltaic systems. In order to analyze the operation characteristics for the protection devices in the case that the Photovoltaic systems with bi-directional power supply are located in the feeder, this paper proposes the test facilities composed of model distribution system, protection device and model Photovoltaic systems. By performing the simulation for operation characteristics for the protection devices based on the test facilities, this paper presents the malfunction mechanism for the protection devices. The test results show that this paper is practical and effective for the technical guideline for the Photovoltaic systems.