• 대한전자공학회논문지SD
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• 제46권11호
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• pp.84-91
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• 2009

본 논문은 multi-level signaling을 이용한 high speed serial link transmitter에 관하여 제안하였다. High speed serial link에서 수 Gb/s를 달성하기 위해 4-pulse amplitude modulation (PAM) 을 사용하였다. 4-PAM은 4개의 level로 한 symbol time에 2 bit data를 전송함으로써 binary signaling보다 2배 빠른 data 전송이 가능해졌다. 제안된 4-PAM transmitter는 전압 output 대신 전류 output을 생성하며 이로 인해 driver의 switching time이 빨라져서 더 높은 속도의 transmitter를 구현할 수 있었다. $2^5-1$ pseudo-random bit sequence (PRBS) 생성기는 built-in self test (BIST)를 하기 위해 on-chip으로 설계되었다. 본 연구는 동부 하이텍 $0.18{\mu}m$ CMOS 공정을 통하여 설계되었으며 1.8 V supply voltage에서 eye 크기가 160 mV 이고 최대 동작 속도는 8 Gb/s이다. 칩 전체 면적은 $0.7\times0.6mm^2$이며 전력 소모는 98 mW이다.

• 한국인터넷방송통신학회논문지
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• 제20권4호
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• pp.81-86
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• 2020

사물인터넷 IoT를 넘어선 지능형사물인터넷 AIoT의 발달로 산업 분야가 전반적으로 변해가고 있다. 또한, 4차 산업 혁명 시대가 도래함 에 따라 자동차 산업 분야에서도 획기적인 변화와 발전이 이루어지고 있는데, 그 대표적인 예시가 바로 "자율주행자동차"라고 할 수 있다. 자율주행자동차에 대한 국내외적 관심이 높아짐에 따라 유관기관들의 관련 연구 또한 활발히 진행되고 있고, 실제로 많은 발전을 이루었으며 제한적이나마 상용화 단계로 까지 발전하였다. 하지만, 운전자가 아닌 자동차에 장착된 다양한 센서 들을 활용하여 데이터를 수집, 분석하여 제어하는 자율주행 자동차의 구조 상 보안에 대한 다중화 된 장치가 미흡하여 해킹에 고스란히 노출되는 경우가 많다. 이 경우, 운전자뿐만 아니라 주변 환경에도 위협이 될 수 있기 때문에 본 논문에서는 자율주행 자동차의 시스템 보안 향상을 위한 새로운 데이터 처리 기능을 제안하고자 한다.

• 지역사회간호학회지
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• 제16권4호
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• pp.517-526
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• 2005

Purpose: The purpose of this study is to find taxi drivers' smoking behavior, self-efficacy and expectation level of success in smoking cessation. It will provide useful information for developing nursing interventions in health promotion programs. Method: The subjects of this study were 271 taxi drivers in Seoul and its metropolitan area. Data were collected using a self-reported questionnaire asking smoking history, smoking behaviors, health problem, stages of change for smoking cessation, self-efficacy and the expectation level of success in smoking cessation. Data were analyzed through descriptive statistics. Pearson's correlation, Mann-Whitney U test, Kruskal-Wallis test and Cronbach's a. Results: Of the taxi drivers, 83.8% were current smokers. Stages of change were as follows: 45.8% were in the precontemplation stage, 26.2% in the contemplation stage, 13.7% in the maintenance stage, 12.2% in the preparation stage and 1.5% in the action stage. In addition. 20.3% of the subjects reported health problems such as hypertension, heart disease, diabetes mellitus and respiratory disease. The expectation level of success in smoking cessation was positively related with self-efficacy. There were statistically significant differences in the expectation level of success in smoking cessation according to the number of cigarettes per day and nicotine dependency. In addition. there were statistically significant differences in self-efficacy according to the number of cigarettes per day, duration of smoking (years) and nicotine dependency. Conclusion: The results of this study suggest that taxi drivers' health problems and smoking rate were serious. Therefore more systematic health promotion programs for smoking cessation should be developed and executed by health care specialists at individual taxi companies.

• 한국지반환경공학회 논문집
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• 제21권11호
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• pp.5-10
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• 2020

건설 현장에서 항타기 전도 사고는 빈도는 낮으나 발생 시 심각한 피해를 야기한다. 항타기 전도 사고의 주원인은 침하에 의한 모멘트 발생임에도 불구하고 KOSHA-C-101-2014, KOSH-A-GUIDE-71-2012, 산업안전보건 기준, NCS 등의 규정에서 철판 사용에 대한 선언적 내용만 있을 뿐 구체적인 요구조건이 명시되어 있지 않다. 이에 항타기 자중, 지반조건에 따라 하부 철판의 제원이 바뀌어야 하지만 현장에서는 임의로 사용되고 있다. 본 연구에서는 수치 해석(Plaxis 2D)을 기반으로 요구되는 최소 철판 두께를 분석 하였다. 토양의 종류(모래, 점토), 하중 분포, 철판 두께(10mm, 20mm, 30mm, 40mm)에 따라 침하 정도와 및 지반 항복 유무를 산출하였으며, 그 결과 모든 조건에서 두께 10mm 철판은 지반 항복을 유발하였다. 두께 20mm부터는 지반 침하로 발생하는 회전각이 허용치인 2° 이내로 분석되었다.

• 한국응급구조학회지
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• 제6권1호
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• pp.199-207
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• 2002

This is a study to evaluate the effects of the safety of ambulance driving and the occurrence of ambulance traffic accidents and to provide basic information for the description of various factors to reduce the ambulance traffic accidents. The major instruments of this study were Korean Self-Analysis Driver Opinionnaire. Questionnaire contains 8 items which measure driver's opinions or attitudees: driving courtesy, emotion, traffic law, speed, vehicle condition, the use of drugs, high-risk behavior, human factor. To take the analysis of data, the total of 187 drivers were investigated ambulance drivers in Gwangju Metropolitan City from 2002. 1. September to 2002. 20. September. The data were analyzed by the path analysis SPSS program. The result are as follows : 1. There was desirable attitude group(58.4%) and undesirable attitude group(41.7%) on safety ambulance driving. 2. It have suggested that rist factors of ambulance traffic accident much affected with emotion and speed control on safety ambulance driving(Y(Accident) = -2.00 + 0.6 X1(Emotion Control) + 0.4 $X_2$(Speed control) + E). 3. Almost 92.1% of respondents have agreed to necessity of emergency medical technics for ambulance drivers.

• 한국직업건강간호학회지
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• 제24권4호
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• pp.363-371
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• 2015

Purpose: The purpose of this study was to investigate the factors influencing health promoting lifestyle of urban bus driver in small-sized companies. Methods: This study included 118 urban bus drivers who completed questionnaires. The data were collected from 6 small-sized bus companies located in a metropolitan city, from January to February 2015. Analyses were done using descriptive statistics, independent t-test, ANOVA, Pearson's correlation, and multiple regression analysis. SPSS/Win 18.0 was used. Results: The scores of HPLP of urban bus drivers were 2.7 (on a 4-point scale). Mean of HPLP sub-scores were self-fulfillment ($3.0{\pm}0.5$), interpersonal relationship ($2.9{\pm}0.5$), physical activity ($2.9{\pm}0.7$), health responsibility ($2.7{\pm}0.5$), healthy diet ($2.6{\pm}0.6$), and stress management ($2.5{\pm}0.5$). Among independent variables, job satisfaction and presence of religion were significantly related to health promoting lifestyle (explained 39.2%). Conclusions: This study revealed that there is a need to strengthen job satisfaction for urban bus drivers' health promoting lifestyle.

• 한국컴퓨터정보학회논문지
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• 제22권10호
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• pp.47-54
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• 2017

In this paper, we propose a connected car platform architecture called Mobile Second for developing of verity convergence services. A Mobile Second platform architecture is designed to provide more powerful and diverse convergence services for vehicles and drivers by applying technologies of Connected Car and ICT Convergence in various ways. The Mobile Second platform is implemented by applying Tizen IVI and Android to hardware platforms for IVI, Nexcom's VTC1010 and Freescale's i.MX6q/dl respectively. The Mobile Second platform provides the driver with the vehicle's information via IVI devices, mobile devices and PCs, etc., and provides Vehicle Selective Gateway(VSG) and Vehicle Control Framework for the driver to control his/her vehicle, and also provides a web framework to enable the use of VSG's APIs for the monitoring and controlling the vehicle information in various mobile environments as well as IVI devices. Since the Mobile Second platform aims to create new variety of services for Connected Car, it includes service frameworks for Smart Care / Self diagonostics, Mood & Entertainment services, and Runtime, libraries and APIs needed for the development of related applications. The libraries given by the Mobile Second Platform provides both a native library for native application support and a Java Script-based library for web application support, minimizing the dependency on the platform and contributing the convenience of developers at the same time.

• Journal of Power Electronics
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• 제19권1호
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• pp.68-78
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• 2019

The emergence of high voltage conversion applications has resulted in a trend of using semiconductor device series associations. Series associations allow for operation at blocking voltages, which are higher than the nominal voltage for each of the semiconductor devices. The main challenge with these topologies is finding a way to guarantee the voltage balance between devices in both blocking and switching transients. Most of the methods that have been proposed to mitigate static and dynamic voltage unbalances result in increased losses within the device. This paper introduces a new series stack topology, where the voltage unbalances are reduced. This in turn, mitigates the switching losses. The proposed topology consists of a circuit that ensures the soft switching of each device, and one auxiliary circuit that allows for switching energy recovery. The principle for the topology operation is presented and experimental tests are performed for two modules. The topology performs excellently for switching transients on each of the devices. The voltage static unbalances were limited to 10%, while the activation/deactivation delay introduced by the lower module IGBT driver takes place in the dynamic unbalances. Thus, the switching losses are reduced by 40%, when compared to hard switching configurations.

• International Journal of Internet, Broadcasting and Communication
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• 제15권4호
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• pp.142-148
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• 2023

In Modern days, Self-driving for modern people is an absolute necessity for transportation and many other reasons. Additionally, after the outbreak of COVID-19, driving by oneself is preferred over other means of transportation for the prevention of infection. However, due to the constant exposure to stressful situations and chronic fatigue one experiences from the work or the traffic to and from it, modern drivers often drive under drowsiness which can lead to serious accidents and fatality. To address this problem, we propose a drowsy driving prevention learning model which detects a driver's state of drowsiness. Furthermore, a method to sound a warning message after drowsiness detection is also presented. This is to use MoveNet to quickly and accurately extract the keypoints of the body of the driver and Dense Neural Network(DNN) to train on real-time driving behaviors, which then immediately warns if an abnormal drowsy posture is detected. With this method, we expect reduction in traffic accident and enhancement in overall traffic safety.

• 융합정보논문지
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• 제10권7호
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• pp.223-231
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• 2020

노인 운전자는 기능저하로 인해 사고 위험성이 증가하지만 스스로 변화를 점검하는 자가-조절 능력 또한 발달한다. 이에 실제 노인 운전자가 운전 능력과 위험성 변화에 대응하는 특성에 대한 정보는 노인의 운전 능력 평가 현장과 연구에 의미있는 근거를 제공할 수 있다. 따라서 본 연구의 목적은 한국 노인 운전자의 운전 위험성 자각 특성을 운전 중 행동과 운전관련 기능변화의 측면에서 분석하여 노인 운전자 평가를 위한 기초 자료를 제공하는 것이다. 지역사회에 거주하는 노인 운전자 500명을 대상으로 자가-보고식 평가를 실시하고 노인 운전자의 운전 위험성 자각 징후를 분석하였다. 그 결과 다수의 노인 운전자가 시각 및 청각이 저하되거나 운전 여건 변화에 적응하는데 어려움을 느낄 때 운전 위험성을 자각하는 특성이 있음을 확인하였다. 반면, 약물 복용이나 간질, 발작, 의식손실 등 의학적 건강 상태 변화에는 둔감하게 반응하는 특성이 확인되었다. 본 연구 결과가 고령화가 가속화되는 한국의 노인 운전자 안전 관리에 기여할 수 있기를 기대한다.