• Proceedings of the Korean Geotechical Society Conference
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• 2005.10a
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• pp.621-628
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• 2005

The concrete lining in tunnel performs structural and nonstructural functions. The concrete lining works as a structural member for released load and residual water pressure in NATM tunnel system. Also concrete lining used for finishing the tunnel surface. The initial crack of concrete lining is reported because of difficulties in construction process, which concrete is injected into 30$\sim$40cm narrow gap between lining form and tunnel surface through 500${\times}$600mm small injection holes in the form. In this paper, we research a reason of initial crack occurrence by the case study of 4 lane wide span tunnel, and propose an improved method for crack minimization in construction process. We verify that the proposed method can give qualified concrete lining by carrying out the concrete injection model test and the numerical analysis of concrete flow.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.283-284
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• 2015

Smartphone, tablet PC, notebook, such as the Internet banking and electronic commerce using a mobile device, as well as process and to their work. While going to high availability and convenience of mobile devices castle, SNS, letters, using an email Smishing financial fraud and leakage of personal information such as crime has occurred many. Smishing smartphone accidents increased sharply from 2013, MERS infection cases, landmine provocative events, such as the delivery of Thanksgiving has occurred cleverly using social engineering techniques. In this paper, i analyze the trends in Smishing hacking attacks on mobile devices since 2014. With regard to social issues, it analyzes the process of hacking attacks Smishing leading to financial fraud to mobile users.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.11
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• pp.2615-2622
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• 2015

Using the mobile device, such as Smartphones tablet PC, online banking and e-commerce, as well as process and to their work. While going to high availability and convenience of mobile devices castle, SNS, letters, using an email Smishing financial fraud and leakage of personal information such as crime has occurred many. Smishing smartphone accidents increased sharply from 2013, MERS infection cases, landmine provocative events, such as the delivery of Thanksgiving has occurred cleverly using social engineering techniques. In this paper, i analyze the trends in Smishing hacking attacks on mobile devices since 2014. With regard to social issues, it analyzes the process of hacking attacks Smishing leading to financial fraud to mobile users. And, in this paper, i propose a secure way and measures of financial damage for mobile Smishing hacking.

• Journal of Advanced Navigation Technology
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• v.11 no.4
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• pp.359-370
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• 2007

Lane tracking and obstacle avoidance are considered two of the key technologies on an unmanned ground vehicle system. In this paper, we propose a method of lane tracking and obstacle avoidance, which can be expressed as vehicle control, modeling, and sensor experiments. First, obstacle avoidance consists of two parts: a longitudinal control system for acceleration and deceleration and a lateral control system for steering control. Each system is used for unmanned ground vehicle control, which notes the vehicle's location, recognizes obstacles surrounding it, and makes a decision how fast to proceed according to circumstances. During the operation, the control strategy of the vehicle can detect obstacle and perform obstacle avoidance on the road, which involves vehicle velocity. Second, we explain a method of lane tracking by means of a vision system, which consists of two parts: First, vehicle control is included in the road model through lateral and longitudinal control. Second, the image processing method deals with the lane tracking method, the image processing algorithm, and the filtering method. Finally, in this paper, we propose a method for vehicle control, modeling, lane tracking, and obstacle avoidance, which are confirmed through vehicles tests.

• The Korean Journal of Emergency Medical Services
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• v.13 no.1
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• pp.61-72
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• 2009

Purpose : This study was conducted to understand the unforeseen phone calls placed through the 1339 emergency medical communication system by residents of the Gwangju/Jeonnam area during the Lunar New Year and Chuseok holidays. Methods : A descriptive research method was implemented using SPSS to analyze 9,047 reported and received consultation phone calls made during the 2008 Lunar New Year holiday (February 6-10) and the 2008 Chuseok holiday (September 13-15) for frequency and percentages. Results : Among the general characteristics of subjects during the Lunar New Year and Chuseok holidays, an examination of the distribution for gender showed more men than women and the distribution for age showed most subjects were thirties, followed by forties, and finally under ten years of age. According to the status of situational calls during the Lunar New Year holiday most were used for in the following order : providing resource information, misdialing and prank calls, and additional consultations. According to the status of situational calls during the Chuseok holiday most were used for in the following order : providing resource information, additional consultations, misdialing and prank calls. According to region most came from Gwangju Metropolitan City Bukgu, followed by Yeosu, Suncheon, and Mokpo in Jeonnam. According to callers, the majority were non-medical persons. According to time most were made between 9:01 and 12:00, while the fewest were made during 3:01 and 6:00. According to treatment department most were made in the following order : internal medicine, pharmacy, and pediatrics. Most medical resource information provided regarded areas outside the callers location. Conclusion : Emergency medical technician will play a central role in the emergency medical information system in the near future.

• Journal of Korean Tunnelling and Underground Space Association
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• v.5 no.4
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• pp.361-370
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• 2003

In this study, the performance of water tightness of water expansional sealing material and gasket was evaluated. The water tightness test was performed varying the type of inner pressure condition, for which the water expansional sealing material was inundated for 5 days to evaluate the ability of water tightness. In order to carry out this test, we made use of two types of water expansional sealing material; general type and combined type with non-expansional rubber. In the case of gasket, EPDM gasket and complex gasket sticked to the water expansional sealing material were applied. The performance of water tightness depended on the construction defect and the deformation of segment. The construction defect and segment deformation were generally expressed by gap and offset of the construction joint. The results, of tests showed that the performance of water tightness was largely influenced by the gap between segments. Management criteria of gap and offset were proposed.

• The Journal of Korean Association of Computer Education
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• v.5 no.3
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• pp.89-106
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• 2002

One of the key success factors for Computer Supported Collaborative Learning(CSCL) environments relies on collaborative reflection. Reflection refers to the active, intellectual thinking for monitoring one's own learning process and continuous internal activities of exploring oneself for new learning experiences. Also, reflective activities are closely related not only with the individual aspect of internal exploration but also with the social aspect of learner-learner interaction. This paper suggests four essential macro-level design strategies such as (1)facilitating collaborative awareness, (2)making thinking visualization, (3)negotiation-mediated knowledge construction, (4)providing metacognitive awareness cues or Questions for scaffolding collaborative reflection in the CSCL environments and made some implications for key functional features for the design and development of system components for CSCL.

• Korean Journal of Environmental Agriculture
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• v.18 no.4
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• pp.339-343
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• 1999

This study was carried out to investigate the effects of treatments and adequate concentration of ethephon on coloring promotion of peel of sweet persimmon 'Nishimurawase' cultivar. High concentration(30 and 40㎎/l) of ethephon treatments increased the coloring of peel. but they were unfavorable to marketability due to the decrease of firmness, the increase of softening ratio, and the short of marketing critical period of fruits. Low concentration(20㎎/l) of ethephon treatment maintained higher marketability in terms of coloring of peel, firmness, softening ratio, and marketing critical period of fruit.

• Magazine of the Korean Society of Hazard Mitigation
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• v.7 no.3
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• pp.75-81
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• 2007

1. 가을철에는 36년 평균($1971{\sim}2006$년) 11.1 (41.6%)개 발생, 0.8개가 우리나라에 영향을 줌(표 1, 그림 1) - 9월 발생 태풍 총 175개(연평균 4.9개) o 비상구역 진입태풍 51개(연평균 1.4개) o 우리나라에 27개 영향(연평균 0.8개) - 10월 발생 태풍 총 135개(연평균 3.8개) o 비상구역 진입태풍 17개(연평균 0.5개) o 우리나라에 3개 영향 - 11월 발생 태풍 충 86개(연평균 2.4개) o 비상구역 진입태풍 3개 o 우리나라에 영향 없음 * 연평균 계산은 소수 둘째자리에서 반올림한 결과임. 2. 가을철 태풍발생수의 장기간 변동 특성(그림 2) - 많이 발생하는 해와 적게 발생하는 해가 주기적으로 반복되고 있음. - 1990년대 후반부터 평년보다 적게 발생하는 경향이 지속되고 있음. 3. 가을철 태풍으로 인한 인명 재산 피해 현황(표 3과 4) - 인명 피해 : 최근 감소 추세 o $2002.8.30{\sim}9.1$ 루사(RUSA, 0215), 246명 (사망 실종 포함) o 재산 피해 최근 증가 추세 o $2002.8.30{\sim}9.1$ 루사 (RUSA, 0215) 5,262,200(백만원) o $2003.9.12{\sim}9.13$ 매미(MABMI, 0314) 4,222,486(백만원) 4. 추석 기간 동안 우리나라에 영향을 준 태풍(표 5) - $1971{\sim}2006$년(36년) 동안 4회 o 1986, 1997, 2000, 2003 o 특히 $2003.9.12{\sim}13$ 매미(0314)에 의한 강풍과 강수로 인하여 막대한 피해 유발 : 고산(12일) 최대풍속 51.1m/s 전남남해안, 영남지방, 강원도 영동지방 $100{\sim}450mm$.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.2
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• pp.98-103
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• 2002

In case of power demand forecasting, the most important problems are to deal with the load of special-days. Accordingly, this paper presents the method that forecasting long (the Lunar New Year, the Full Moon Festival) and short(the Planting Trees Day, the Memorial Day, etc) special-days peak load using neural networks and regression models. long and short special-days peak load forecast by neural networks models uses pattern conversion ratio and four-order orthogonal polynomials regression models. There are using that special-days peak load data during ten years(1985∼1994). In the result of special-days peak load forecasting, forecasting % error shows good results as about 1 ∼2[%] both neural networks models and four-order orthogonal polynomials regression models. Besides, from the result of analysis of adjusted coefficient of determination and F-test, the significance of the are convinced four-order orthogonal polynomials regression models. When the neural networks models are compared with the four-order orthogonal polynomials regression models at a view of the results of special-days peak load forecasting, the neural networks models which uses pattern conversion ratio are more effective on forecasting long special-days peak load. On the other hand, in case of forecasting short special-days peak load, both are valid.