• Journal of Community Nutrition
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• v.6 no.2
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• pp.103-109
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• 2004

Body antioxidant status is an important factor for the prevention of many chronic diseases in the elderly. This study was done to investigate antioxidant status and its relationship to immune response by measuring plasma cytokine (IL-2 and IL-6) levels in elderly women. Subjects were 76 elderly women aged over 60 years, visiting Jangwhi Social Welfare Center of Seongbook-Gu in Seoul. Subjects were divided into 3 groups according to age (< 65, 65 - 74, > 75). Dietary intakes were assessed by semi-quantitative food frequency questionnaires (SFFQ). Plasma vitamin C level was measured by 2,4-dinitrophenylhydrazine method and plasma levels of vitamin E, A and ${\beta}$-carotene were measured by HPLC. Plasma levels of IL-2 and IL-6 were determined with a solid phase sandwich enzyme linked-immuno-sorbent assay (ELISA) using commercial kits. The average intakes of antioxidant vitamins were 96.3mg (137.5% of RDA) for vitamin C and 523.3 ${\mu}$gRE (74.8% of RDA) for vitamin A in elderly women. All of the average plasma levels of antioxidant vitamins were within normal range. However the percentage of the elderly women with deficiency plus marginal values were 7.9% in vitamin C, 9.2% in vitamin A and 7.9% in vitamin E. Plasma levels of IL-2 and IL-6 were 27.1${\pm}$7.1pg/ml and 5.9${\pm}$5.3pg/ml in elderly women. Correlation data showed that plasma IL-2 level was negatively correlated with plasma vitamin C level. In addition, IL-6 level was also negatively correlated with plasma vitamin C, A and E levels, respectively. There was a significant positive correlation between erythrocyte thiobarbituric acid-reactive substance(TB-ARS) level and plasma IL-2 or IL-6 levels. In addition, erythrocyte TBARS level showed a significant positive correlation with plasma total antioxidant status (TAS) level and a significant negative correlation with plasma vitamin C level. Overall results might imply that the decreased levels of antioxidant vitamins result in an increase in oxidative stress and thereby increase cytokine production such as IL-2 and IL-6. However further research is required to elucidate these relationships.

• Journal of Korean society of Dental Hygiene
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• v.12 no.2
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• pp.275-284
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• 2012

Objectives : The purpose of this study was to examine the oral health behavior of shipbuilding company workers in some regions in a bid to provide information on the oral health plans for industrial fields. Methods : The subjects in this study were 310 workers in 10 shipbuilding companies and suppliers in Jeolla Namdo Province, on whom a self-administered survey was conducted. Results : 1. Concerning general information about the subjects who participated in the research, gender was possessed 94.8% by men and 5.2% by women. Age was the largest in 31~40 years old with 44.2%. Marital status was the largest in the married with 64.5%. It was the largest in under high school graduate with 71.9% for academic background, in 2,000,000 won~3,000,000 won with 49.0% for monthly family income, and in cooking with 33.9% for work field. 2. Research subjects' toothbrushing time was indicated to be the largest in after having breakfast. It was indicated to be twice a day with 41.3% for toothbrushing frequency. 90.3% of the respondents are not using auxiliary oral hygiene devices. 3. Recognition on periodontal health status was found larger in workers whose response was that their own periodontal health status is 'healthy' than workers who responded that their status is 'not healthy.' Workers, who don't have subjective symptom on periodontal status, were indicated to be larger. 4. Ratio of subjects with tooth scaling experience accounted for 59.7%. The ratio of tooth scaling experience was indicated to be different depending on academic background and monthly family income. Conclusions : Academic credential, monthly family income and the line of work were identified as the main factors to affect oral health care of the shipbuilding workers. Oral health education and dynamic implementation of corporate oral health promotion which are designed to meet the needs of workers are required.

• 한국지역지리학회:학술대회
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• 2009.08a
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• pp.108-115
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• 2009

An increase in oil and gas plants caused by development of process industry have brought into the increase in use of flammable and toxic materials in the complex process under high temperature and pressure. There is always possibility of fire and explosion of dangerous chemicals, which exist as raw materials, intermediates, and finished goods whether used or stored in the industrial plants. Since there is the need of efforts on disaster damage reduction or mitigation process, we have been conducting a research to relate explosion model on the background of real 3D terrain model. By predicting the extent of damage caused by recent disasters, we will be able to improve efficiency of recovery and, sure, to take preventive measure and emergency counterplan in response to unprepared disaster. For disaster damage prediction, it is general to conduct quantitative risk assessment, using engineering model for environmentaldescription of the target area. There are different engineering models, according to type of disaster, to be used for industry disaster such as UVCE (Unconfined Vapor Cloud Explosion), BLEVE (Boiling Liquid Evaporation Vapor Explosion), Fireball and so on, among them.we estimate explosion damage through UVCE model which is used in the event of explosion of high frequency and severe damage. When flammable gas in a tank is released to the air, firing it brings about explosion, then we can assess the effect of explosion. As 3D terrain information data is utilized to predict and estimate the extent of damage for each human and material. 3D terrain data with synthetic environment (SEDRIS) gives us more accurate damage prediction for industrial disaster and this research will show appropriate prediction results.

• International Journal of Automotive Technology
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• v.8 no.6
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• pp.731-744
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• 2007

A method for dynamic analysis and design calculation of a Powertrain Mounting System(PMS) including Hydraulic Engine Mounts(HEM) is developed with the aim of controlling powertrain motion and reducing low-frequency vibration in pitch and bounce modes. Here the pitch mode of the powertrain is defined as the mode rotating around the crankshaft of an engine for a transversely mounted powertrain. The powertrain is modeled as a rigid body connected to rigid ground by rubber mounts and/or HEMs. A mount is simplified as a three-dimensional spring with damping elements in its Local Coordinate System(LCS). The relation between force and displacement of each mount in its LCS is usually nonlinear and is simplified as piecewise linear in five ranges in this paper. An equation for estimating displacements of the powertrain center of gravity(C.G.) under static or quasi-static load is developed using Newton's second law, and an iterative algorithm is presented to calculate the displacements. Also an equation for analyzing the dynamic response of the powertrain under ground and engine shake excitations is derived using Newton's second law. Formulae for calculating reaction forces and displacements at each mount are presented. A generic PMS with four rubber mounts or two rubber mounts and two HEMs are used to validate the dynamic analysis and design calculation methods. Calculated displacements of the powertrain C.G. under static or quasi-static loads show that a powertrain motion can meet the displacement limits by properly selecting the stiffness and coordinates of the tuning points of each mount in its LCS using the calculation methods developed in this paper. Simulation results of the dynamic responses of a powertrain C.G. and the reaction forces at mounts demonstrate that resonance peaks can be reduced effectively with HEMs designed on the basis of the proposed methods.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.3
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• pp.88-97
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• 2013

This paper presents a robust air-to-fuel ratio (AFR) control algorithm for managing exhaust gas recirculation (EGR) systems. In order to handle production tolerance, deterioration and parameter-varying characteristics of the EGR system, quantitative feedback theory (QFT) is applied for designing the robust AFR control algorithm. A plant model of EGR system is approximated by the first order transfer function plus time-delay (FOPTD) model. EGR valve position and AFR of exhaust gas are used as input/output variables of the plant model. Through engine experiments, parameter uncertainty of the plant model is identified in a fixed engine operating point. Requirement specifications of robust stability and reference tracking performance are defined and these are fulfilled by the following steps: during loop shaping process, a PID controller is designed by using a nominal loop transmission function represented on Nichols chart. Then, the frequency response of closed-loop transfer function is used for designing a prefilter. It is validated that the proposed QFT-based AFR control algorithm successfully satisfy the requirements through experiments of various engine operating points.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.8
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• pp.91-98
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• 2003

In the structural analysis of a launch vehicle, the construction of loading functions and the determination of responses to them are very important. Among many kinds of loads, acoustic load generated by exhaust is a random load that can be described in a statistical manner. In this study, loading functions corresponding to the acoustic loads are constructed and applied to the structural analysis of launch vehicle. Acoustic loading functions are constructed using source allocation method. Structural analyses are carried out by using finite element modelling and frequency response function of finite element model. The stresses resulting from acoustic loads and acceleration power spectral density functions at interfaces of each section are calculated. These analyses are essential for the development of environmental test specifications and associated dynamic design requirements which are necessary to ensure overall vehicle reliability.

• 한국방재학회:학술대회논문집
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• 2011.02a
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• pp.166-166
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• 2011

한국건설기술연구원내에 세계 최초로 UHPC(초고성능 콘크리트)를 활용한 보도사장교를 설계 및 시공하여 공용중이다. 초고성능 콘크리트(UHPC, Ultra High Performance Concrete)는 기존의 콘크리트의 단점을 극복하기 위하여 강섬유 및 혼화재료를 사용하여 고강도화와 더불어 인장강도, 휨강도, 균열에 대한 저항성, 전단강도 및 내충격성을 대폭 개선시켜서 구조부재의 연성 및 강도를 확보하기 위해 개발된 것으로서 한국건설기술연구원이 독자적 연구를 바탕으로 UHPC를 개발하였고, KICT-UHPC의 특성을 충분히 반영한 보도사장교를 한국건설기술원내에 실구조물로 시공하였다. 한국건설기술연구원내 본관 1, 2동 연결 보도사장교(SUPER BRIDGE 1)의 진동실험을 통해 UHPC 보도사장교의 동특성(고유진동수 및 모드형상)을 평가하였다. 대상교량에는 보도사장교의 캔틸레버 구조 특성에 의해 발생하는 진동을 제어하기 위한 질량 264kg의 난간형 수직진동제어장치(TMD) 4대가 설치되어 있으며, 부가질량의 운동을 기계적으로 구속하거나 구속을 해제하여 TMD의 작동을 켜거나 끌 수 있도록 되어있다. TMD의 가동 및 정지시 동특성을 비교하는 정밀한 검증 실험을 통하여 TMD 설치에 의한 동특성의 변화도 평가하였다. 가진망치에 의한 충격실험으로부터 획득한 가속도 시간이력 데이터와 가진망치의 가진력 시간이력 데이터를 사용하여 주파수응답함수(FRF, frequency response function)를 계산하고, 이로부터 Super Bridge I의 동적모드형상과 고유진동수를 추출하였다. 1차 모드의 고유진동수는 TMD 정지시 2.2949 Hz, TMD 작동시 2.0996 Hz로서 8%정도 감소하였다. 충격해머에 의한 가진 실험을 통해 세계 최초로 시공한 UHPC 보도사장교의 진동특성과 관련한 신뢰성 있는 자료를 확보할 수 있었다.

• Journal of Biomedical Engineering Research
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• v.28 no.3
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• pp.423-428
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• 2007

Programmable FIR filters are used in various signal processing tasks in medical ultrasound imaging, which are one of the major factors increasing hardware complexity. A widely used method to reduce the hardware complexity of a programmable FIR filter is to encode the filter coefficients in the canonic signed digit (CSD) format to minimize the number of nonzero digits (NZD) so that the multipliers for each filter coefficients can be replaced with fixed shifters and programmable multiplexers (PM). In this paper, a new structure for programmable FIR filters with a improved frequency response and a reduced hardware complexity compared to the conventional shift-and-add architecture using PM is proposed for implementing a very small portable ultrasound scanner. The CSD codes are optimized such that there exists at least one common nonzero digit between neighboring coefficients. Such common digits are then implemented with the same shifters. For comparison, synthesisable VHDL models for programmable FIR filters are developed based on the proposed and the conventional architectures. When these filters have the same hardware complexity, pass-band ana stop-band ripples of the proposed filter are lower than those of the conventional filter by about $0.01{\sim}0.19dB$ and by about $5{\sim}10dB$, respectively. For the same filter performance, the hardware complexity of the proposed architecture is reduced by more than 20% compare to the conventional SaA architecture.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2000.04a
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• pp.15-25
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• 2000

Cardiac, respiratory, electrodermal and frontal (F3, F4) EEG responses were analyzed and compared during to slides of International Affective Picture System (IAPS) in the study on 42 students. Physiological responses during 20s of exposure to slides intended to elicit happiness (nurturant and erotic), sadness, disgust, surprise, fear or anger emotions were quite similar and were expressed in heart rate (HR) deceleration, decreased HR variability (HRV), specific SCR, increased non-specific SCR frequency (N-SCR), and EEG changes exhibited in theta increase, alpha-blocking and increased beta activity, and frontal asymmetry. However, some emotions demonstrated variations of the response magnitudes, enabling to differentiate some paris of emotions by several physiological parameters. The profiles showed higher magnitudes of HRV and EEG responses in exciting (i.e., erotic) and higher cardiac and respiratory responses in surprise. The most different pairs were exciting-surprise (by HR, HRV, theta, and alpha asymmetry), exciting-sadness (by theta, alpha, and alpha asymmetry), and exciting-fear (by HRV, theta, F3 alpha, and alpha asymmetry). Nurturant happiness yielded the least differentiation. Differences were found as well within negative emotions, e.g., anger-sadness were differentiated by HRV and theta asymmetry, while disgust-fear by N-SCR and beta asymmetry. Obtained results suggest that magnitudes of profiles of physiological variables differentiate emotions evoked by affective pictures, despite that the patterns of most responses were featured by qualitative similarity in given passive viewing context.

• Science of Emotion and Sensibility
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• v.21 no.3
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• pp.73-82
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• 2018

Attempts have been made to recognize social emotion, including competition-cooperation, while designing interaction in work places. This study aimed to determine the cardiac response associated with classifying competition-cooperation of social emotion. Sixty students from Sangmyung University participated in the study and were asked to play a pattern game to experience the social emotion associated with competition and cooperation. Electrocardiograms were measured during the task and were analyzed to obtain time domain indicators, such as RRI, SDNN, and pNN50, and frequency domain indicators, such as VLF, LF, HF, VLF/HF, LF/HF, lnVLF, lnLF, lnHF, and lnVLF/lnHF. The significance of classifying social emotions was assessed using an independent t-test. The rule-base for the classification was determined using significant parameters of 30 participants and verified from data obtained from another 30 participants. As a result, 91.67% participants were correctly classified. This study proposes a new method of classifying social emotions of competition and cooperation and provides objective data for designing social interaction.