• Title/Summary/Keyword: Noise regulation

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A Study on the Determination of the Screening Factors for the Tunnel and the Overbridge of the Electric Railway (전기철도 터널 및 고가 구조물의 차폐계수 산정에 대한 연구)

  • Choi, Kyung;Lee, Hyang-Beom;Kim, Hyeong-Seok;Kim, Hak-Cheol
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.67 no.9
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    • pp.1249-1256
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    • 2018
  • For the screening factor of the tunnel and overbridge structure in the electrified railway, the ITU-T regulation denotes only a theoretical estimation method, and the actual numeric values are notified differently by the official announcement of each nations. In this study, the factors which can affect the screening factor are investigated and analysed by FEM and a suitable calculation method based on multi-conductor line theory for the current pre-estimation formula for the induction noise voltage in the national notice is presented. The case studies are performed using the real data of the tunnel and the overbridge of the electrified railway, and a satisfactory formula for the determining of screening factor is derived.

A Study on the Regulation of Blasting Noise at Home and Abroad (국내외 발파소음 규제에 대한 연구)

  • Oh, Ki-Taek
    • Proceedings of the Korean Society of Disaster Information Conference
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    • 2023.11a
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    • pp.89-90
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    • 2023
  • 대단위 건축물 및 구조물 철거작업시 철거사업 참여 주체인 발주자, 감리자, 시공자 및 근로자등의 안전사고 예방을 위한 사전 위험성평가 및 안전대책 수립, 수립된 안전대책 이행에 대한 역할이 매우 중요하다. 건축물 및 구조물 철거작업 공법은 인력철거공법 및 장비철거공법, 발파철거공법으로 구분되며 발파철거공법 적용시 발생되는 소음 및 진동을 계측하여 환경규제 기준내로 준수해야 한다. 본 연구는 발파공업에 의한 철거작업시 국내·외 소음 규제치 비교를 통해 국내의 발파공법에 의한 소음 규제치를 합리적으로 조정하여 건축물 및 구조물의 철거작업시 발파공업의 채택이 활성화 되기를 기대한다.

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A Study on Environmental Standards of School Building (교사환경기준에 관한 연구)

  • Hong, Seok-Pyo;Park, Young-Soo
    • The Journal of Korean Society for School & Community Health Education
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    • v.1 no.1
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    • pp.11-43
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    • 2000
  • The purpose of this study was, through analyzing the previous researches, to grasp the present status of environment of school building(ESB), research the sundry records of each element and, through comparative analysis of the standard of ESB in Korea, the United States, and Japan, select the normative standard of ESB, to clarify the point at issue presented in Regulation of Construction & facility Management for Elementary and and Secondary School in Korea, and to suggest an alternative preliminary standard of ESB. To carry out a research for this purpose, these were required: 1. to investigate the existing present status of ESB, 2. to make a comparative analysis of the standard of ESB in each country, 3. to suggest the normative standard of preliminary standard of ESB, 4. to analyze the controversial points of the standard of ESB in Korea, 5. to suggest an alternative preliminary standard of ESB. The conclusions were as follows: 1. Putting, through analyzing the previous researches, the existing present status of ESB together, it seemed that lighting environment, indoor air environment and noise environment were all in poor conditions. 2. In the result of a comparative analysis of the standard of ESB in Korea, Japan and the United States, in Korea the factors of each lighting and indoor air environment were not presented properly, in Japan, in lighting environment aspect, the standard on natural lighting and the factors on brightness were not presented., and in the USA the essential factors of each environment were throughly presented. In the comparison of the standards on each factor, Korea showed that the standard level presented was less properly prescribed than those of the USA and Japan but it also showed that the standard levels prescribed in the USA and in Japan were mostly similar to the standard levels in records investigated. 3. With the result of the normative standard selection on School Builiding environment factor of prescribed in this study, the controversial points of the standard of ESB in Korea were analyzed and the result was utilized to suggest new preliminary standard of ESB. 4. As the result of the analysis of the controversial points of the standard of ESB in Korea, it was found that the standard of ESB in Korea should be established on a basis of School Health Act and be concretely presented in School Health Regulation and School Health Rule. The factors of each environment was improperly presented in the existing standard of ESB in Korea. Moreover the standard of them was inferior to that of the records investigated and those of in the USA and in Japan and it also showed that the standard of it in Korea was improper to maintain Comfortable Learning Environment. 5. A suggested preliminary standard of ESB acquired through above study as follows: 1) In this study a new kind of preliminary standard of ESB is divided into lighting environment, indoor air environment, noise environment, odor environment and for above classification, reasonable factor and standard should be established and the controling way on each standard and countermeasures against it should be considered. 2) In lighting environment, the factors of natural lighting are divided into daylight rate, brightness, glare. In the standard on each factor, daylight rate should secure 5% of a mean daylight rate and 2% of a minimum daylight rate, brightness ratio of maximum illumination to minimum illumination should be under 10:1, and in glare there should not be an occurrence factor from a reflector outside of the classroom. And the factors of unnatural lighting are illumination, brightness, and glare. In the standard on each factor, illumination should be 750 lux or more, brightness ratio should be under 3 to 1, and glare should not occur. And Optimal reflection rate(%) of Colors and Facilities of Classroom which influences lighting environment should be considered. 3) In indoor air environment factors, thermal factors are divided into (1) room temperature, (2) relative humidity, (3) room air movement, (4) radiation heat, and harmful gases (5) CO, (6) $CO_2$ that are proceeded from using the heating fuel such as oval briquettes, firewood, charcoal being used in most of the classroom, and finally (7) dust. In the standard on each factor, the next are necessary; room temperature: $16^{\circ}C{\sim}26^{\circ}C$(summer : $E.T18.9{\sim}23.8^{\circ}C$, winter: $E.T16.7{\sim}21.7^{\circ}C$), relative humidity: $30{\sim}80%$, room air movement: under 0.5m/sec, radiation heat: under $5^{\circ}C$ gap between dry-bulb temperature and wet-bulb temperature, below 1000 ppm of ca and below 10ppm of $CO_2$, dust: below 0.10 $mg/m^3$ of Volume of dust in indoor air, and ventilation standard($CO_2$) for purification of indoor air : once/6 min.(about 7 times/40 min.) in an airtight classroom. 4) In the standard on noise environment, noise level should be under 40 dB(A) and the noise measuring way and the countermeasures against it should be considered. 5) In the standard on odor environment, odor level under Physical Method should be under 2 degrees, and the inspecting way and the countermeasures against it should be considered.

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A Study on Utilization of Drone for Public Sector by Analysis of Drone Industry (국내외 드론산업 동향 분석을 통한 공공분야에서의 드론 활용방안에 대한 연구)

  • Sim, Seungbae;Kwon, Hunyeong;Jung, Hosang
    • Journal of Information Technology Services
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    • v.15 no.4
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    • pp.25-39
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    • 2016
  • The drone is an unmanned aerial vehicle which has no human pilot. Drones can be classified into military drones, commercial drones, and personal drones by usage. Also, drones can be classified from large-sized to nano-sized drone by size and autonomous, remote controlled drone by control type. Especially, military drones can be classified into low-altitude drones, medium-altitude, and high-altitude drones by altitude. Recently, the drone industry is one of the fast growing industries in the world. As drone technologies have become more advanced and cost-effective, Korean government has set its goal to become a top-level country in drone business. However, the government's strict regulation for drone operations is one of the biggest hurdles for the development of the related technologies in Korea and other countries. For example, critical problems for drone delivery can be classified into technical issues and institutional issues. Technical issues include durability, conditional awareness, grasp and release mechanisms, collision avoidance systems, drone operating system. Institutional issues include pilot and operator licensing, privacy rules, noise guidelines, security rules, education for drone police. This study analyzes the trends of the drone industry from the viewpoint of technology and regulation. Also, we define the business areas of drone utilization. Especially, the drone business types or models for public sector are proposed. Drone services or functions promoting public interests need to be aligned with the business reference model of Korean government. To define ten types of drone uses for public sector, we combine the business types of government with the future uses of drones that are proposed by futurists and business analysts. Future uses of drones can be divided into three sectors or services. First, drone services for public or military sectors include early warning systems, emergency services, news reporting, police drones, library drones, healthcare drones, travel drones. Second, drone services for commercial or industrial services include parcel delivery drones, gaming drones, sporting drones, farming and agriculture drones, ranching drones, robotic arm drones. Third, drone services for household sector include smart home drones.

Comparison Study of Image Quality of Direct and Indirect Conversion Digital Mammography System (직접 및 간접변환 방식의 디지털 유방 X선 촬영시스템의 영상화질 비교 연구)

  • Park, Hye-Suk;Oh, Yu-Na;Jo, Hee-Jeong;Kim, Sang-Tae;Choi, Yu-Na;Kim, Hee-Joung
    • Progress in Medical Physics
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    • v.21 no.3
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    • pp.239-245
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    • 2010
  • The purpose of this study is to comprehensively compare and evaluate the characteristics of image quality for digital mammography systems which use a direct and indirect conversion detector. Three key metrics of image quality were evaluated for the direct and indirect conversion detector, the modulation transfer function (MTF), normalized noise power spectrum (NNPS), and detective quantum efficiency (DQE), which describe the resolution, noise, and signal to noise performance, respectively. DQE was calculated by using a edge phantom for MTF determination according to IEC 62220-1-2 regulation. The contrast to noise ratio (CNR) was evaluated according to guidelines offered by the Korean Institute for Accreditation of Medical Image (KIAMI). As a result, the higher MTF and DQE was measured with direct conversion detector compared to indirect conversion detector all over spatial frequency. When the average glandular dose (AGD) was the same, direct conversion detector showed higher CNR value. The direct conversion detector which has higher DQE value all over spatial frequency would provide the potential benefits for both improved image quality and lower patient dose in digital mammography system.

A Study of Enemy Aptitude of Pistol Sound Source for Space Estimation (공간평가를 위한 피스톨음원의 적정성에 관한 연구)

  • Shon, Jang-Ryul;Kim, Jung-Joong
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.15 no.3 s.96
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    • pp.320-328
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    • 2005
  • Last target of architectural acoustics is that people wish to convey voice effectively from the space adaptively in use purpose in building. But, how exactly through space sound (sound source) that wish to deliver from indoor can be passed method to do quantification and evaluate quantity of sound by method to serve indoor architectural acoustics estimation summer period and methods to estimate definition propose. This Study searches special quality of sound source about MLS signal that is occurred short-answer sound source (pistol sound source) and nondirectional speaker among indoor sound estimation method, and measure and analyzed reverberation time (RT60), definition (C80, D50) by regulation of each ISO 3382 in age place (classroom, hall, gymnasium). Analysis result and sound factor among could know that d of two sound sources converges in measurement error extent about reverberation time (RT60) of analysis incidental and sound factors and value shows change irregularly about sound factor of D50, C80, pistol sound source judged there is problem. Also, could know that problem is happened in deflection except reverberation time is in deflection analysis with wave that measure each in fixed distance in branch. Finally, when differ size of sound source and measure about change of sound pressure level in case measure sound pressure level giving difference about 10 dB, sound factor could know that there is no different effect.

Running Safety Analysis of Railway Vehicle passing through Curve depending on Rail Inclination Change (레일 경좌 변화에 따른 곡선부 통과열차의 주행안전성 해석)

  • Kim, Moon Ki;Eom, Beom Gyu;Lee, Hi Sung
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.23 no.3
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    • pp.199-208
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    • 2013
  • So far today, there is a speed limit by the radius of curve based on operation regulation in domestic railway, however a study for the maximum running speed at the curved section without any derailment would be necessary. The two major factors related to the running safety of railway vehicle are classified as the railway vehicle condition and the track condition. In terms of the rail inclination among many other factors, the determination of rail inclination within the possible limit is necessary for the geometrical structure of the optimum track. The disregard of the geometrical parameter related to the rail inclination may cause a serious problem to the running safety of railway vehicle. This study is focusing on the analyzing of running safety regard to the change of rail inclination among the many other parameters to improve derailment safety, so that there is an affection analysis of the running safety regard to the change of rail inclination in the ideal and geometric track condition. Also There is an affection analysis of the running safety regard to the simultaneous change of rail inclination and the running speed at the curved section. According to analysis results of running safety, In case that the left and right rail inclination are 1/40, the running safety of this condition defined than other conditions. Also, the rail inclination of conventional lines is 1/40, Therefore, the railway vehicle passing through curve is safe when the railway vehicle runs in conventional lines.

A Study on Market Power in Futures Distribution (선물 유통시장에서 시장지배력에 관한 연구)

  • Liu, Won-Suk
    • Journal of Distribution Science
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    • v.15 no.11
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    • pp.73-82
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    • 2017
  • Purpose - This paper aims to investigate a profit maximizing incentive of foreign traders in distributing the KOSPI 200 Futures. Such an incentive may induce unsophisticated retail traders to suffer loss from speculative trading. Since Korean government increased the entry barriers of the market to protect unsophisticated traders, the market size has been decreasing while the proportion of the contract held by foreign traders has been increasing. These on going changes make the market imperfectly competitive, where a profit maximization incentives of foreign traders are expected to grow. In this paper, we attempt to find any evidence of such behavior, thereby providing implications regarding market policy and market efficiency. Research design, data, and methodology - According to Kyle(1985), an informed trader exploits his/her monopoly power optimally in a dynamic context so that he/she makes positive profit, where he/she could conceal his/her trading utilizing noise trading as camouflage. We apply the KOSPI 200 Futures market to the Kyle's model: foreign traders who take into account the effect of his/her trading to maximize expected profits as an informed trader, retail investors as noise traders, and financial institutions as market makers. To find any evidence of monopolistic behavior, we test the variants of trading volume and price data of the KOSPI 200 Futures over the period of 2009 and 2017. Results - First, we find that the price of the KOSPI 200 Futures are more volatile than the price of underlying asset. Second, we find that monopolistic foreign trader's trading order flows are consistent with exploiting his/her monopoly power to maximize profit. Finally, we find that retail investors' trading order flows are inversely consistent with maximizing profit, that is, uninformed retail investors suffer loss continuously in speculative trading against informed traders. Conclusions - Our results show that the quantity of strategic order flows may have a large effect on the price, therefore, resulting the market inefficiency. The results also imply that, in implementing regulations, the depth of the market must be considered to maintain market liquidity, and suggesting interesting research topics regarding the market structure.

Characteristics of Acoustic Indicators Evaluating Speech Intelligibility in Korean Elementary School Classrooms (초등학교 일반교실의 음향성능 실태측정 및 평가지표 특성 고찰)

  • Lee, Seong-Bok;Kim, Myung-Jun;Yang, Hong-Seok
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.25 no.7
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    • pp.462-469
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    • 2015
  • This study was carried out to examine characteristics of various acoustic indicators evaluating speech intelligibility such as reverberation time(T30), D50, C50 and speech transmission index(STI) in Korean elementary school classrooms. Results showed that mean T30 at middle frequencies(500 Hz to 2000 Hz) measured in 9 classrooms was about 0.75 s, which exceeds a regulation specified on American National Standards(ANSI); 0.60 s. Mean D50, C50 and STI were 60 % to 66 %, +2 dB to +3 dB, and 0.65, respectively. The maximum difference in D50 and C50 according to different receiver points in a classroom was 13 % and 2.5 dB, while the maximum difference in T30 was 0.03 s. Whereas STI measured in classrooms has relatively low correlation with other indicators, correlation between D50 and C50 was high, R2=.9964. In addition, T30 and C50 were fitted well as logarithmic regression curve with R2=.9610. It was +3.73 dB in C50 and 68 % in D50 which are the value corresponding to 0.60 s in T30 on this curve.

A Case Study of GTX A Tunnel Station Blasting with Electronic Detonator (GTX A 터널정거장에 대한 전자뇌관 적용 시공 사례)

  • Hwang, Nam-Sun;Kim, Kyung-Hyun;Kim, Jeoung-Hwan;Seong, Yoo-Hyeon;Lee, Chang-Won
    • Explosives and Blasting
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    • v.39 no.3
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    • pp.24-34
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    • 2021
  • Electronic detonators are widely used in various construction sites due to accurate delay time. Including the cases with exceeded noise and vibration from site using electric/non-electric detonator, electronic detonators are used to improve blast fragmentation or to reduce the cost of secondary partial blasting. Furthermore, the number of cases using electronic detonators are increased for reduction of the cost and construction period by maximizing operations efficiency. This case study is about applying electronic detonators on large section station, tunnel construction site which is the part of urban area GTX A project. Although it was initially planned to utilize non-electric detonators, damage was inflicted on safety-thing. We have considered blasting method using electronic detonators as solution of this problem. By applying electronic detonators, we not only satisfied environmental regulations but also prevented nearby safety-thing from getting damaged. In addition, we were able to shorten the construction period than the initial plan by conducting single simultaneous blasting on large section station, in order to ensure safe and efficient construction.