• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2011년도 춘계학술대회 논문집
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• pp.808-813
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• 2011

There are hundreds of thousands call center workers wearing acoustic device. However, researches and noise exposure measurements on the noise transmitted from acoustic devices have seldom been performed due to the difficulty of measurement and to the absence of the measuring method in Korea. The aim of this study is to set up management measures to protect hearing loss on the call operator by acquiring measurement data of noise transmitted from the headset Noise exposure measurements of 17 operators were performed in 7 call centers and Head and Torso Simulator method in compliance with the ISO Standard 11904-2 was used for the measurement of noise transmitted from the headset Sound pressure levels(SPL) transmitted from the headset were 73.2~86 dB(A). The operator exposed to the highest SPL set up his volume control at 9 which was the highest volume level. The volume control level, adjustable from 1 to 9, could be identified 12 out of 17 operators and the range of volume levels was 4.5~9. As a result of Pearson Correlation Analysis, the correlation between volume level and SPL transmitted from the headset showed high relation as significance at the 0.672 level(p<0.05). To protect hearing loss of call center operators, it is more practical and effective measure to limit the volume level below the noise exposure level, i.e. 85 dB(A), rather than to carry out noise monitoring considering cost-effective aspect.

• 한국동물위생학회지
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• 제30권2호
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• pp.191-196
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• 2007

The slaughter process for cattle will inevitably transfer some bacteria onto the carcasses. The goal of food safety programs is to minimize and effectively remove this contamination. This study was attempted by the Verif $EYE^{TM}$ machine-vision technology that might be useful for reducing microbial indicator counts and could reduce the contamination chance of E coli O157:H7 and Salmonella spp on beef carcasses. For the evaluation of the effectiveness of the Verif $EYE^{TM}$ technology, 80 samples were examined by the inspection device over 15 days. On an examination of FDS-positive samples compared to negative controls from the same carcasses, aerobic plate counts were bigger than the negative control samples (5.26 vs 4.60 log). Enterobacteriaceae counts were greater on the positive samples than the corresponding negative control samples (2.07 vs 1.17log). There was a consistent correlation between samples detected by the Verif $EYE^{TM}$ system with detectable counts. For example, 100% of positive samples had detectable APC and 91.2% of positive samples had detectable TCC. Therefore, if areas detected as positive for contamination by the Verif $EYE^{TM}$ system were removed from the carcasses, significant sources of microbial contamination will be reduced for objective compliance with HACCP. This results suggest that the use of Verif $EYE^{TM}$ machine-vision technology might be useful for reducing microbial indicator counts (APC, TCC) and could help reduce the risk of presence of E coJi O157:H7 and Salmonella spp on Beef carcasses.

• 재활간호학회지
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• 제5권2호
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• pp.99-112
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• 2002

The purpose of this study is to determine the effect of oral vitamin C supplements on blood sugar and serum lipid level(total cholesterol, triglyceride, high density lipoprotein, low density lipoprotein) in non-insulin independent diabetes mellitus. The study design was a non equivalent control group pre-test post-test design. Data for the study were collected from June 24 to August 31, 2001. The ninty-five research subject were assigned to experimental group(51) and control group(44). Vitamin C(3g/day) was given to 51 subjects for 4 weeks. Following a 12h overnight fasting, blood sample was obstaind at baseline and at the end of 4week - supplementation. Blood samples were taken for plasma vitamin C concentration, fasting blood sugar, HbA1c and serum lipid level. The pre-equivalent test was used by Chi-squre, t-test and two group's pre and post experimental differences were analyzed by t-tset to compare with each other. The results of this study were as follows ; 1. The difference between the two groups in plasma vitamin C concentration was significant(t=-12.950, p=.000). 2. The difference between the two groups in fasting blood sugar was significant(t=5.293, p=.000). 3. The difference between the two groups in HbA1c was not significant(t=1.758, p=.082). 4. The difference between the two groups in total cholesterol, HDL, LDL was significant(t=3.786, p=.000 ; t=-5.515, p=.000 ; t= 4.169, p = .000). These results suggest that megadose vitamin C supplementation be effective in lowering fasting blood sugar, serum lipids and increasing plasma vitamin C. Thus dietary measures to increase plasma vitamin C may be on important health strategy for reducing the compliance of diabetic patients.

• 한국안전학회지
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• 제17권4호
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• pp.184-188
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• 2002

According to a recent report, Korea first reached aging society in 2000 and it is forecasted that the number of aged people over 65 years old will increase form 7.13%(2000) to 14% or more of total population in Korea in 2022. As many aged peoples are employed as day labor under the financial circumstances after Korean Financial Crisis, it is critical that we should take safety control measures for them. Thus, this study focused on analyzing aged accidents in terms of their characteristics, based on the actual trend of industrial accidents from 1996 to 2001 and the applications of medical treatment for the affected or wounded in Busan metropolitan area for recent 3 years (1999 to 2001) in order to analyze accident characteristics to cope with emergent aging period. As a result of analyzing the above data by job type, it was found that the construction work amounted to 38% of total job type. This result implies that accidents of the aged often occurs in 3D jobs including construction works without reasonable automation, which requires us to establish some preventive policies against those accidents. Moreover, it is found that rapid increasing accidents such as upset or occupational diseases or damages are typically attributed to those in the aged, mainly because the aged employees over 55 years old often have disadvantageous physical conditions such as relatively degraded balance and muscular control ability comparing to the younger. Therefore, it recommended that we should make effective safety policies for the aged and actively apply those policies to them. Moreover, it is required that we should encourage them to actively participate in safety compliance through corresponding trainings.

• 조명전기설비학회논문지
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• 제18권6호
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• pp.183-190
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• 2004

본 논문은 냉난방 인버터 에어컨용 전원시스템에 역률개선 회로인 부분 스위칭 PFC 모듈을 적용하여 입력의 역률 개선 및 전류의 고조파 성분을 최소화하여 IEC555-2규정을 만족하는 입력 전원부를 설계하여 인덕터부하에 적용되는 회로 설계시의 문제점들을 해결 할 수 있는 방안들을 제시하였다. 그리고 출력전압의 상승을 억제하면서 전류파형을 개선하는 방법 및 부분 스위칭 PFC회로를 제안하여 스위칭 횟수를 적게 함으로써 압축기의 모터에 인가 할 수 있는 전압을 상승시켜 모터 적정 운전 전압을 확립하였으며, 효율이나 경제성 및 전자 노이즈 등의 문제점들을 해결하였다. 그리고 에어컨의 소비 전력을 줄일 수 있다. 이상의 결과에서 시스템 총합 운전에너지 효율이 상승되는 것을 확인하는 모든 사항은 시뮬레이션과 실험을 통하여 그 타당성을 입증했다.

• 한국소음진동공학회논문집
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• 제21권7호
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• pp.615-621
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• 2011

There are hundreds of thousands call center workers wearing acoustic device. However, researches and noise exposure measurements on the noise transmitted from acoustic devices have seldom been performed due to the difficulty of measurement and to the absence of the measuring method in Korea. The aim of this study is to set up management measures to protect hearing loss on the call operator by acquiring measurement data of noise transmitted from the headset. Noise exposure measurements of 17 operators were performed in 7 call centers and head and Torso simulator method in compliance with the ISO standard 11904-2 was used for the measurement of noise transmitted from the headset. Sound pressure levels(SPL) transmitted from the headset were 73.2~86 dB(A). The operator exposed to the highest SPL set up his volume control at 9 which was the highest volume level. The volume control level, adjustable from 1 to 9, could be identified 12 out of 17 operators and the range of volume levels was 4.5~9. As a result of pearson correlation analysis, the correlation between volume level and SPL transmitted from the headset showed high relation as significance at the 0.672 level(p<0.05). To protect hearing loss of call center operators, it is more practical and effective measure to limit the volume level below the noise exposure level, i.e. 85 dB(A), rather than to carry out noise monitoring considering cost-effective aspect.

• Journal of Korean Biological Nursing Science
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• 제20권4호
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• pp.205-213
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• 2018

Purpose: The purpose of this study was to confirm the compliance of the application of a ventilator-associated pneumonia bundle and understand its effects on the decrease in the incidence of ventilator-associated pneumonia. Methods: This was a retrospective observational study with history control group design. Subjects were selected from January to June 2014, prior to the intervention using the ventilator-associated pneumonia bundle. Subjects were also selected from October 2014 to March 2015, 3 months after the intervention. The number of subjects was 112 before the intervention, and 107 after the intervention. Results: The number of nurses who followed the bundles increased from 8 out of 29 (27.6%) before the intervention to 19 out of 29 (65.5%) after the intervention (odd ratio= 4.99, confidence interval= 1.63-15.25, p= .004). There were 3 cases of ventilator-associated pneumonia before the intervention and 1 case after the intervention. The ventilator days were 2,143 days before the intervention and 2,232 days after the intervention. The ventilator-associated pneumonia rate of the 1,000 ventilator days was 1.40 before the intervention and decreased to 0.45 after the intervention. Conclusion: This study is meaningful, as there has been little research conducted regarding the application of the ventilator-associated pneumonia bundle in South Korea.

• 한국의학물리학회지:의학물리
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• 제29권4호
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• pp.123-136
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• 2018

The complex dose distribution and dose transfer characteristics of intensity-modulated radiotherapy increase the importance of precise beam data measurement and review in the acceptance inspection and preparation stages. In this study, we propose a process map for the introduction and installation of high-precision radiotherapy devices and present items and guidelines for risk management at the acceptance test procedure (ATP) and commissioning stages. Based on the ATP of the Varian and Elekta linear accelerators, the ATP items were checked step by step and compared with the quality assurance (QA) test items of the AAPM TG-142 described for the medical accelerator QA. Based on the commissioning procedure, dose quality control protocol, and mechanical quality control protocol presented at international conferences, step-by-step check items and commissioning guidelines were derived. The risk management items at each stage were (1) 21 ionization chamber performance test items and 9 electrometer, cable, and connector inspection items related to the dosimetry system; (2) 34 mechanical and dose-checking items during ATP, 22 multileaf collimator (MLC) items, and 36 imaging system items; and (3) 28 items in the measurement preparation stage and 32 items in the measurement stage after commissioning. Because the items presented in these guidelines are limited in terms of special treatment, items and practitioners can be modified to reflect the clinical needs of the institution. During the system installation, it is recommended that at least two clinically qualified medical physicists (CQMP) perform a double check in compliance with the two-person rule. We expect that this result will be useful as a radiation safety management tool that can prevent radiation accidents at each stage during the introduction of radiotherapy and the system installation process.

• 정보보호학회논문지
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• 제22권1호
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• pp.155-167
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• 2012

클라우드 컴퓨팅 서비스는 이용자 요구에 실시간으로 유연하게 컴퓨팅 자원을 제공하고 사용량만큼 과금하는 고효율의 차세대 IT 서비스이다. 그러나 이용자는 데이터를 '위탁'하고, 인프라, 플랫폼, 어플리케이션 서비스를 '제공'받는 '위탁/제공'의 서비스 구조와 적용기술, 자원공유, 데이터센터 위치 등으로부터 비롯된 많은 위협에 직면해 있다. 클라우드 서비스 도입의 가장 큰 걸림돌로 작용하는 보안과 신뢰성을 담보하기 위해서는 객관적인 평가 기준이 필요하다. 지금까지 정보보호관리체계는 조직의 보안관리 및 IT 운영의 보안 지표로 활용되어 왔다. 그러나 클라우드 컴퓨팅 서비스는 기존의 조직 내 IT 환경과는 다른 관점의 보안관리와 평가기준이 필요하다. 본 논문에서는 클라우드 특성에 맞는 정보보호관리체계를 설계하기 위하여 클라우드 서비스의 핵심요소를 위협관리영역으로부터 도출하고 기본적인 보안관리가 누락되지 않도록 기존 정보보호관리체계의 모든 통제영역을 포함하고 있다. 또 온라인 셀프환경에 따른 서비스 이용을 지원하고 서비스 계약, 제공자 사업현황을 포함하는 서비스 보안관리를 추가하여 설계한다.

• Steel and Composite Structures
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• 제37권6호
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• pp.663-678
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• 2020

This paper proposes a novel topology optimization method generating multiple materials for external linear plane crack structures based on the combination of IsoGeometric Analysis (IGA) and eXtended Finite Element Method (X-FEM). A so-called eXtended IsoGeometric Analysis (X-IGA) is derived for a mechanical description of a strong discontinuity state's continuous boundaries through the inherited special properties of X-FEM. In X-IGA, control points and patches play the same role with nodes and sub-domains in the finite element method. While being similar to X-FEM, enrichment functions are added to finite element approximation without any mesh generation. The geometry of structures based on basic functions of Non-Uniform Rational B-Splines (NURBS) provides accurate and reliable results. Moreover, the basis function to define the geometry becomes a systematic p-refinement to control the field approximation order without altering the geometry or its parameterization. The accuracy of analytical solutions of X-IGA for the crack problem, which is superior to a conventional X-FEM, guarantees the reliability of the optimal multi-material retrofitting against external cracks through using topology optimization. Topology optimization is applied to the minimal compliance design of two-dimensional plane linear cracked structures retrofitted by multiple distinct materials to prevent the propagation of the present crack pattern. The alternating active-phase algorithm with optimality criteria-based algorithms is employed to update design variables of element densities. Numerical results under different lengths, positions, and angles of given cracks verify the proposed method's efficiency and feasibility in using X-IGA compared to a conventional X-FEM.