• Journal of the Korea Safety Management & Science
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• v.19 no.4
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• pp.221-230
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• 2017

Recently, service quality must reflect several demands of customers who show rapid and various changes so as to be compared with the past. So, objective and rapid methods for them are necessary more. For them, first of all, service company must calculate their standard of service quality accurately by measuring service quality exactly. To measure service quality accurately, this researcher collected and analyzed data by survey for customers who are customers of logistics services, grasped potential satisfaction standard(P) by 5 point Likert scale and one survey for accurate classification of quality attributes through weighted customer satisfaction coefficient changing quality attributes by developing the study on Kano model and Timko's customer satisfaction coefficient, and suggested Potential Customer Satisfaction Improvement index(PCSI) for examining the improvement of customer satisfaction so as to utilize them as an index of differentiated and concrete measurement of service quality.

• Journal of Korean Society of Transportation
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• v.35 no.2
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• pp.160-168
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• 2017

In the past 10 years, the accidents caused by drowsy driving have occupied about 23% of all traffic accidents in Korea expressway network and this rate is the highest one among all accident causes. Unlike other types of accidents caused by speeding and distraction to the road, the accidents by drowsy driving should be managed differently because the drowsiness might not be controlled by human's will. To reduce the number of accidents caused by drowsy driving, researchers previously focused on the spot based analysis. However, what we actually need is a segment (link) and occurring time based analysis, rather than spot based analysis. Hence, this research performs initial effort by adapting link concept in terms of drowsy driving on highway. First of all, we analyze the accidents caused by drowsy in historical accident data along with their road environments. Then, links associate with driving time are analyzed using digital tachograph (DTG) data. To carry this out, negative binomial regression models, which are broadly used in the field, including highway safety manual, are used to define the relationship between the number of traffic accidents on expressway and drivers' behavior derived from DTG. From the results, empirical Bayes (EB) and potential for safety improvement (PSI) analysis are performed for potential risk segments of accident caused by drowsy driving on the future. As the result of traffic accidents caused by drowsy driving, the number of the traffic accidents increases with increase in annual average daily traffic (AADT), the proportion of trucks, the amount of DTG data, the average proportion of speeding over 20km/h, the average proportion of deceleration, and the average proportion of sudden lane-changing.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.156-156
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• 2020

가뭄은 다른 자연재해에 비해 진행 속도가 느리고 발생 시작 시기가 명확하지 않다. 또한 피해지역이 광범위하다는 점에서 사회, 경제적 피해와 농업 생산 시스템 및 수확량 등 농업 전반에 걸쳐 직접적인 영향을 미치고 있다. 전지구적 기후변화로 인해 국내의 가뭄 발생빈도는 2000년 이후 증가하고 있으며, 가뭄의 정량적 분석은 선제적 가뭄 대응을 위해 필요하다. 현재 국내에서는 여러 유관기관에서 지상 관측 데이터를 활용하여 가뭄을 모니터링하고, 가뭄 공간 분포 지도를 제공하고 있다. 하지만 지상 관측 데이터를 통한 가뭄 분포 지도는 미계측 지역에 대한 데이터 취득이 어렵고, 지형학적 특성을 고려하지 못하는 한계점이 있다. 이러한 한계점을 보완하기 위해 수자원 및 재해 분야에서 위성영상이 활용되고 있다. 위성영상을 활용한 가뭄 판단 및 예측에는 정규식생지수 (Normalized Difference Vegetation Index, NDVI)가 사용되고 있으며, 식생지수는 가뭄 발생, 진행 등에 있어 즉각적인 반응이 어렵다는 단점이 있다. 본 연구에서는 잠재 증발산과 실제 증발산의 비를 이용해 산정된 위성영상 기반 가뭄 지수인 Evaporative Stress Index (ESI)를 활용하였다. NASA (National Aeronautics and Space Administration)에서 제공하는 ESI는 전지구를 대상으로 5km 해상도로 제공하고 있다. 하지만 국내 가뭄 판단을 위해서는 높은 해상도의 영상이 필요하며, 본 연구에서는 MODIS (Moderate Resolution Imaging Spectroradiometer) 영상을 활용한 ESI의 산정을 통해 해상도의 문제를 개선하고자 한다. 산정한 500m 해상도의 ESI는 기존 5km 해상도의 ESI와 비교 검증하였으며, SPI 및 과거 가뭄 발생 현황 자료를 근거로 ROC (Receiver Operating Characteristics) 분석을 통해 시군 단위 농업가뭄평가의 적용성을 확인하고 한다.

• Journal of the Korea Safety Management & Science
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• v.21 no.2
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• pp.15-23
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• 2019

Among service industries of knowledge based economic era, the roles of educational service field are becoming more important and standard of educational service makes a direct effect on economic development and social growth. Therefore, accurate measurement of service quality is the most important assignment and the measurement of the service quality remains difficult assignment. So, this researcher classified quality attributes applying weighted value and found potential satisfaction level(PSL) and potential customer demand improvement index(PCDI) for trainees participating in national manpower business so as to suggest measurement of service quality and easiness of use and then, calculated satisfaction position and opportunity cost by quality factor with Taguchi's loss fraction. And, improvable satisfaction level was measured, opportunity cost by degree of customer dissatisfaction was quantitatively measured, and a model that can indicate with economic factors was suggested. In addition, methodology of measuring quality cost that can be reduced by quality improvement and direction of strategic decision-making for deciding items to be improved preferentially were suggested with qualitative index that can indicate the degree of customers' dissatisfaction by loss.

• Journal of the Korea Safety Management & Science
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• v.21 no.1
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• pp.9-16
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• 2019

Logistics companies are worrying about securing of differential competitiveness so as to be competitive companies in keen logistics market. The ground is how users are satisfied by sell-established service system to respond not only economic feasibility of logistics costs but also diversity and advancement of logistics needs. The competitiveness of logistics companies is also caused by customer satisfaction of service and only companies finding and satisfying customer needs continuously may be more competitive. For the competitiveness, it's the most important to analyze demands of current and potential customers and their pursuing value properly. Therefore, this researcher grasped PSL for online logistics service users with 5-point Likert-scale and quality-level decision method that consider the weighted value based on Kano model, measured customer's potential Demand for service through PCDI, and suggested methodology for deciding the priority of the improvement with loss function of Taguchi.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.5
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• pp.729-740
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• 2022

This study analyzed the effects of job stress and sleep disorders on sleepiness during the daytime for a night-shift urban railway crew. As a result of the analysis, measurements on a daytime sleepiness index were higher for the crew than those during other working hours, indicating that the degrees of sleepiness and drowsiness were severe. Afterwards, aromatic essential oils, which are generally known to help relieve sleep disorders and stress, were utilized to verify the effect on stress on night-shift workers. The experimental group treated with aromatherapy was found to show improved stress reduction and overall activity levels in the autonomic nervous system compared to an untreated control group. This study proves that night work by an urban railway crew negatively affects stress levels by increasing stress and negatively affects the autonomous nervous system, also showing that an aromatherapy treatment can be a good alternative to alleviate these conditions. The results of this study are expected to help prevent safety accidents by relieving the stress of nighttime workers.