• 한국항해항만학회지
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• 제28권1호
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• pp.17-22
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• 2004

이 논문에서는 해양사고 통계예측 결과의 의미를 쉽게 이해할 수 있는 3차원 가시화 시스템의 구현에 관해서 기술했다. 이 시스템 개발에는 그래픽 사용자 인터페이스 방식(GUI)과 웹(Web) 기반 가상현실(VR) 기술을 주로 적용하였다. 그리고, 매일의 상황을 예보하기 위하여 시간기반 해양사고 예측모델과 위험수준 지표를 개발하였다. 시스템 작동실험 결과, 3차원 가상공간에 단순한 색으로 복잡한 통계결과를 나타낼 수 있었다. 또한, 매일의 위험수준을 막대 그래프에 나타낼 수 있었다.

• 대기
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• 제30권2호
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• pp.195-207
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• 2020

This study aims to introduce the structure of the impact-based heat health warning system on 165 counties in South Korea developed by the National Institute of Meteorological Sciences. This system was developed using the daily maximum perceived temperature (PTmax), which is a human physiology-based thermal comfort index, and the Local ENSemble prediction system for the probability forecasts. Also, A risk matrix proposed by the World Meteorological Organization was employed for the impact-based forecasts of this system. The threshold value of the risk matrix was separately set depending on regions. In this system, the risk level was issued as four levels (GREEN, YELLOW, ORANGE, RED) for first, second, and third forecast lead-day (LD1, LD2, and LD3). The daily risk level issued by the system was evaluated using emergency heat-related patients obtained at six cities, including Seoul, Incheon, Daejeon, Gwangju, Daegu, and Busan, for LD1 to LD3. The high-risks level occurred more consistently in the shorter lead time (LD3 → LD1) and the performance (r_s) was increased from 0.42 (LD3) to 0.45 (LD1) in all cities. Especially, it showed good performance (r_s = 0.51) in July and August, when heat stress is highest in South Korea. From an impact-based forecasting perspective, PTmax is one of the most suitable temperature indicators for issuing the health risk warnings by heat in South Korea.

• 한국안전학회지
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• 제31권4호
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• pp.156-163
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• 2016

There exists required safety integrity level (SIL) to assure safety in accordance with international standards for every electrical / electronics / control equipment or systems with safety related functions. The SIL is allocated from lowest level (level 0) to highest level (level 4). In order to guarantee certain safety level that is internationally acceptable, application of methodology for SIL allocation and demonstration based on related international standards is required. However, the theoretical and practical study for safety integrity level is barely under way in the domestic railway industry. This research studied not only the global process of SIL allocation to guarantee safety in accordance with international standards for safety related equipment and system, but the quantitative methodology based on international standard and the semi-quantitative methodology as alternative way for SIL allocation. Specifically, the systematic SIL allocation for platform screen door system of railway is studied applying the semi-quantitative methodology in order to save much time and effort compared to quantitative method.

• 한국ITS학회 논문지
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• 제13권1호
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• pp.26-34
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• 2014

본 연구에서는 교차로의 안전성을 제고를 위해, 교차로 접근로의 차량 접근속도분포에 기초하여 차량이 통과할 때 경험할 것으로 기대되는 딜레마 구간 길이를 산정하여 이를 위험도 평가수치로 활용하고자 하였다. 현장 교차로에 모형 적용 결과 대체로 모든 접근로에서 딜레마 구간이 발생하고 있었는데, 이는 황색시간이 잘못 적용된 결과인 것으로 분석되었으며, 황색시간을 적절히 재산정하여 모형에 적용한 결과 위험도가 개선되는 것을 확인할 수 있었다. 또한, 위험도 평가시 속도분포를 정규분포로 가정하고 적용했을 때, 실제 속도분포를 적용했을 때의 근사치에 해당되는 값을 얻을 수 있었다. 교차로의 위험도를 평가하여 위험도 수치가 높은 교차로 경우, 위험도를 개선시키기 위해서는 황색시간을 재조정하여 딜레마 구간의 크기를 줄어들게 하거나, 황색시간을 그대로 유지해야 한다면 단속카메라 등 차량의 접근속도를 낮출 수 있는 수단을 활용하여 차량의 속도를 황색시간 산정 기준속도 이하가 되도록 제어해야한다.

• 한국의류학회지
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• 제25권7호
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• pp.1247-1257
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• 2001

The objectives of the study were to examine apparel purchasing behavior in internet shopping malls and the level of perceived risk when internet users purchase online. For this research, 15,000 internet users were given questionaries via E-mail, or special website online. The sum of 1958 questionaries were used for statistical analyses. Using, SAS package, factor analysis, Crobach's ${\alpha}$, t-test, $\chi$$^2$-test, frequency and multi-response analysis were performed. As the results, 19% out of internet users had bought apparel products through internet shopping malls. Men had more purchasing experiences in apparels as well as general products than women. Among apparel products, T-shirts/shirts were purchased the most by internet shoppers. For perceived risks, 6 factors(quality risk, time/convenience risk, size and appearance risk, privacy risk and social/psychological risk) were investigated for this study. The level of perceived risk was lower when people had a purchasing experience in internet shopping mall than when they didn't. The level of perceived risk was lower when people had purchasing intend about apparels than when they didn't. Based on these results, marketing strategies will be suggested.

• 한국경영과학회지
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• 제28권2호
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• pp.17-33
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• 2003

The explosive growth of the internet-based transactions requires not only a secure payment system but also an appropriate trust measuring methodology and secure transaction protocols to guarantee the minimal risk for the transacting entities involved in specific transactions. Especially, in internet auction systems where either buyers or sellers or both can be more than one in one transaction, providing those systems that make sure no one transacting entity takes a major risk becomes critical. In this paper, an improved trust measuring method using a relationship-based internet community for an auction system is proposed. The proposed system incorporates fuzzy set and calculation concepts to help build trust matrices and models, which is used to measure the level of risk involved in a specific auction trade concerned. Also, to optimize the auction trade process in terms of cost and time, the proposed system recommends a differentiated trade protocol according to the risk level involved in each auction trade. To test the appropriateness of the proposed trusted auction system, a prototype system has been developed under a Windows-NT environment.

• 한국인터넷방송통신학회논문지
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• 제22권2호
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• pp.51-62
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• 2022

본 논문에서는 환자의 자세를 기반으로 행동을 예측하여, 의료진에 의해 입력된 개인의 병력 중심의 프로파일과 신체정보, 침상의 기본 정보를 모두 조합하여 침대에서의 낙상 위험을 예측하는 모델을 설계하고, 위험의 수준을 판단할 수 있는 알고리즘을 제시한다. 낙상 위험 예측은 크게 환자의 프로파일을 활용한 정성적 낙상 위험 노출도 평가와 실시간 낙상 위험 측정 단계로 구분된다. 정성적 낙상 위험 노출도는 의료진이 낙상 위험과 관련된 환자의 건강 상태를 점검하여 위험 노출도를 평가함으로써 위험 등급이 결정된다. 실시간 낙상 위험 측정 단계에서는 환자의 침대에서의 자세를 인식하고 환자의 정성적 위험등급 정보가 고려된 낙상 위험 측정을 위한 규칙 기반 정보를 추출한다. 인식된 환자 자세 정보와 정성적 위험평가 정보를 모두 조합하여 시그모이드 함수를 활용하여 최종 낙상 위험 수준을 예측한다. 본 연구에서 제시된 절차와 예측 모델은 입원 환자를 위한 낙상 사고 예방과 환자 안전을 위한 개인화 서비스에 크게 기여할 것으로 기대된다.

• 전기학회논문지
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• 제60권2호
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• pp.266-272
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• 2011

Real Time Pricing(RTP) is used not only to stabilize the price volatility in electricity market, but to hedge the price risk for Load Serving Entity(LSE). This paper presents an efficient method to reduce the risk of the price volatility in real-time electricity market. For designing the RTP, load patterns of customer are calculated by applying the demand elasticity and customer's utility is also analyzed to compute the RTP revenue through the risk-attribute of the LSE. In the end, the distribution of the LSE's profits can be evaluated to lead the optimal RTP value, depending on the level of customer's participation. Results from the case study based on PJM data are reported to illustrate the proposed method.

• 지역사회간호학회지
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• 제29권4호
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• pp.476-487
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• 2018

Purpose: The present study is focused on understanding weight perception related with individual- and school-level multifactorial origins, underestimated and overestimated respectively, in normal body weight adolescents. Methods: Using the 2017 Korea Youth Risk Behavior Web-based Survey data of 45,902 students from 799 secondary schools, a multilevel multinomial logistic regression analysis was performed where adolescents (level1) were nested within schools (level 2). Results: At the school level, the average school body mass index (BMI, $kg/m^2$) and physical education were associated with weight perception among both boys and girls. In boys, geographic areas were associated with weight underestimation. At the individual level, perceived economic status, weekly allowance, BMI ($kg/m^2$), smartphone usage time (hrs/day) and perceived stress were associated with weight perception among both boys and girls. Age, paternal education, academic achievement and alcohol use were associated with weight perception among girls, while part-time job and physical activity were associated with weight perception among boys. Conclusion: Our findings underscore the importance of individual- and school-level environments in developing correct weight perception and have implications for school health education to establish healthy lifestyle behaviors for all adolescents.

• Asian Pacific Journal of Cancer Prevention
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• 제15권6호
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• pp.2523-2527
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• 2014

Background: Serum thyroglobulin detection plays an essential role during the follow-up of thyroid cancer patients treated with total/near total thyroidectomy and radioiodine ablation. The aim of this retrospective study was to evaluate the relationship between stimulated serum thyroglobulin (Tg) level at the time of high dose $^{131}I$ ablation and risk of recurrence, using a three-level classification in patients with differentiated thyroid cancer (DTC) according to the ATA guidelines. Also we investigated the relationship between postoperative stimulated Tg at the time of ablation and DxWBS results at 8-10 months thereafter. Materials and Methods: Patients with radioiodine accumulation were regarded as scan positive (scan+). If there was no relevant pathological radioiodine accumulation or minimal local accumulation in the thyroid bed region, this were regarded as scan negative (scan-) at the time of DxWBS. We classified patients in 3 groups as low, intermediate and high risk group for assessment of risk of recurrence according to the revised ATA guidelines. Also, we divided patients into 3 groups based on the stimulated serum Tg levels at the time of $^{131}I$ ablation therapy. Groups 1-3 consisted of patients who had Tg levels of ${\leq}2ng/ml$, 2-10 ng/ml, and ${\geq}10ng/ml$, respectively. Results: A total of 221 consecutive patients were included. In the high risk group according to the ATA guideline, while 45.5% of demonstrated Scan(+) Tg(+), 27.3% of patients demonstrated Scan(-) Tg(-); in the intermediate group, the figures were 2.3% and 90.0% while in the low risk group, they were 0.6% and 96.4%. In 9 of 11 patients with metastases (81.8%), stimulated serum Tg level at the time of radioiodine ablation therapy was over 10, however in 1 patient (9.1%) it was <2ng/mL and in one patient it was 2-10ng/mL (p=0.005). Aggressive subtypes of DTC were found in 8 of 221 patients and serum Tg levels were ${\leq}2ng/ml$ in 4 of these 8. Conclusions: We conclude that TSH-stimulated serum thyroglobulin level at the time of ablation may not determine risk of recurrence. Therefore, DxWBS should be performed at 8-12 months after ablation therapy.