• Title/Summary/Keyword: low level

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Low Frequency Pass-by Noise for Road Vehicle (도로교통 소음원에 의한 저주파 소음실태)

  • 정성수;서상준;조문재;김용태
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.11a
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    • pp.533-536
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    • 2003
  • The Low frequency(1-200 Hz) noise levels radiated by road traffic were investigated. The results showed that the peak pass-by noise of truck with speed of 60km/h was about 75㏈. For the infra-sound frequency range, the noise was about 65㏈ and it was less value than expected. But the noise level will be increase as increasing the speed. The pass-by noise for train was also measured for comparison. The peak train noise was about 95㏈ and it will be enough noise level for a human body to give nuisance.

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Development of Multi-wavelength Laser Medical Therapy Apparatus (다파장 레이저치료기의 개발)

  • Cheon, Min-Woo;Kim, Seong-Hwan;Park, Yong-Pil;Lee, Ho-Sik;Kim, Tae-Gon
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.20 no.8
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    • pp.736-741
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    • 2007
  • Low level laser therapy has various therapy effects, This paper performed the basic study for fabricating the low level laser therapy apparatus, and one of the goals of this paper was to make this apparatus used handily. The apparatus has been fabricated using the laser diode and microprocessor unit. The apparatus used a 660nm, 785nm and 850nm laser diode for laser medical therapy and was designed for a pulse width modulation type to increase stimulation effects. To raise the stimulus effect of the human body, the optical irradiation frequency could be set up. In result, the $1{\sim}10\;Hz$ irradiation frequency could be controlled stably.

RADIATION SHIELDING EVALUATION OF IP-2 PACKAGES FOR LOW- AND INTERMEDIATE-LEVEL RADIOACTIVE WASTE

  • Kim, Min-Chul;Choi, Jong-Rak;Chung, Sung-Hwan;Ko, Jae-Hoon
    • Nuclear Engineering and Technology
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    • v.40 no.6
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    • pp.511-516
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    • 2008
  • Korea Hydro & Nuclear Power Co., Ltd. (KHNP) developed new IP-2 packages to transport low- and intermediate-level radioactive waste (LILW) steel drums from nuclear power plants to a disposal facility in accordance with IAEA and Korean transport regulations of radioactive material. Radiation shielding evaluation of the packages was carried out to demonstrate compliance with the regulatory requirements for IP-2 packages of radioactive material. Dose rate limits of LILW drums contained in the packages were determined.

Dynamic Relationships of Poverty and Delinquency Trajectories (빈곤과 비행 발달궤적의 역동적 관계)

  • Chung, Ick-Joong
    • Korean Journal of Child Studies
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    • v.30 no.3
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    • pp.113-125
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    • 2009
  • This study advances knowledge of developmental patterns in poverty and delinquency; data was obtained from waves 1-5 (2003-2007) of the Korea Youth Panel Survey. Semi-parametric group-based modeling (SGM) identified 4 trajectories of poverty from age 13 to 17 : non-poor, poverty increasing, low-level continuous poverty and chronic poverty groups and five developmental trajectories of delinquency : non-offending, late onset, low-level continuous, desisting, and chronic groups. A joint trajectory method predicted patterns of delinquency conditional on poverty trajectories. Chronic and low-level continuous poverty groups were more likely than others to follow chronic trajectories of delinquency; the non-poor group was more likely to be non-offending. Implications of this study for youth welfare were discussed to reduce risk for delinquency.

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AN OBSERVER-BASED DTC OF INDUCTION MOTORS DRIVEN BY 3-LEVEL INVERTER FOR IMPROVING LOW SPEED OPERATION (3 레벨 인버터로 구동되는 유도전동기 직접 토크제어의 저속운전 성능 개선)

  • Yun, J.H.;Choi, S.K.;Lee, S.H.;Lee, K.B.;Yoo, J.Y.;Song, J.H.;Choi, I.
    • Proceedings of the KIEE Conference
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    • 2000.07b
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    • pp.1030-1032
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    • 2000
  • Direct torque control algorithm for 3-level inverter-fed induction motors is proposed. Conventional selection method of the stator voltage vector shows problems of stator flux drooping phenomenon and undesirable torque control appeared especially at the low, speed operation. To overcome these problems, a proposed method uses intermediate voltage vectors, which are inherently generated in 3-level inverters. An adaptive observer is also employed to estimate some state-variables and motor parameters, which takes a deep effect on the performance of the low speed operation. Simulation and experiment results verify effectiveness of the proposed algorithm.

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Dynamic Analysis of Base-Isolated Low-level Structures Under Earthquake Excitation (지진시 저층건물 면진구조의 동적 거동해석)

  • Moon, Byung-Young;Kang, Gyung-Ju;Kang, Beom-Soo;Kye-Soo, Kim
    • Proceedings of the KSME Conference
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    • 2001.06b
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    • pp.448-453
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    • 2001
  • This paper presents an analytical evaluation of the effect of motion on seismic responses of base isolated low-level building and experimental studies to evaluate isolation performances of a rubber bearing. Dynamic responses induced by earthquake were evaluated by response analyses, taking the rubber bearing of the base isolation devices into account. In the experiment, vibration tests were carried out using a model for rubber bearings as isolation devices against earthquake in order to investigate the isolation performances of the rubber bearings. Several kinds of rubber bearing for base isolated low-level building against earthquake are examined. As a result, it is shown that the effect of the motion on the response of the building and the base response is well controlled from a seismic design standpoint.

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Men's Role Conflicts in Dual-Earner Family (맞벌이 가족 남서의 역할갈등에 관한연구)

  • 김태현
    • Journal of Families and Better Life
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    • v.16 no.1
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    • pp.81-94
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    • 1998
  • The purpose of this study is to examine men's role conflicts of dual-earner family based on man's role type. Man's role type is composed of man's sex role attitude and family-role performance and categorized in four types such as traditionalism type neo-traditionalism type equalitarianism type and inconsistancy type. The test analysis can be summarized as follows; First test analysis can be summarized as follows; role performance and man's role conflict as working hours is long wife's role requirement is high family-role conflict as working hours is long wife's role requirement is high family-role is not commit man's role conflict directly affected. In addition indirect affect through family-role performance shows that man's role conflict level is low as level of income is high level of income difference between man and wife is low child is younger and intent to modern sex-role attitude. Second looking into the difference role conflict to man's role type it shows that equalita ianism type's role conflict is low and man's role conflict in traditionalism and neo-traditonalism types is high.

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Development of Laser Diode Medical Therapy Apparatus for Blood Stream Improvement (혈류 개선용 레이저다이오드 치료기 개발)

  • Cheon, Min-Woo;Kim, Seong-Hwan;Park, Yong-Pil
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.06a
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    • pp.496-496
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    • 2007
  • Low level laser therapy has various therapy effects. This paper performed the basic study for fabricating the low level laser therapy apparatus, and one of the goals of this paper was to make this apparatus used handily. The apparatus has been fabricated using the laser diode and microprocessor unit. The apparatus used a 7850m Laser diode for blood stream improvement and was designed for a pulse width modulation type to increase stimulation effects. In result, we could get the light power of 785nm wavelength.

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Sophistication of Export Basket: The Case of Petrochemical Industries in Ulsan, Korea (수출산업 고도화전략에 대한 연구: 울산지역 석유화학산업을 중심으로)

  • Lee, Byeong Wan;Kim, Tae-Hyun
    • Korea Trade Review
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    • v.44 no.1
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    • pp.237-251
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    • 2019
  • This paper seeks to recommend strategic policy options geared towards enhancing sophistication level of Ulsan City's major export industries in the Republic of Korea. Ulsan's major export industries, including shipbuilding, automobile and petrochemical industries, turn out to be based mostly on low to medium technology with low R&D intensity suggesting relatively low level of product sophistication. Using a recent Eurostat high-tech industry classification table which suggests 9 high-tech industries, the paper identifies Ulsan's chemical industry as the only RCA industry. Focusing on chemical industry products at HS 6-digit level, specific products are identified at the efficiency frontier for future policy considerations.

Decade Long Survey of Low-level Laser Therapy/Photobiomodulation (LLLT/PBM) Therapy for Oral Mucositis Treatment

  • Ryu, Hyun Seok;Abueva, Celine;Chung, Phil-Sang;Woo, Seung Hoon
    • Medical Lasers
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    • v.10 no.3
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    • pp.138-145
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    • 2021
  • Low-level laser therapy or photobiomodulation (LLLT/PBM) therapy has been widely applied to enhance and accelerate the recovery of oral mucositis. This study investigates the documented effect of LLLT on oral mucositis caused by chemotherapy. This review appraises 6 animal studies and 12 clinical studies published in the Pubmed database during the past 10 years, related to the application of LLLT for the treatment of mucositis. Despite varied parameters and diverse conditions, the assessed articles indicate that application of LLLT on oral mucositis using near-infrared wavelengths is prophylactic, reduces pain, and enables a rapid recovery. Various combined treatments were also identified among the published papers, which further establishes the efficacy of LLLT as a viable treatment.