• Asia pacific journal of information systems
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• v.19 no.2
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• pp.117-137
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• 2009

Recently, intelligent traffic information systems have enabled people to forecast traffic conditions before hitting the road. These convenient systems operate on the basis of data reflecting current road and traffic conditions as well as distance-based data between locations. Thanks to the rapid development of ubiquitous computing, tremendous context data have become readily available making vehicle route planning easier than ever. Previous research in relation to optimization of vehicle route planning merely focused on finding the optimal distance between locations. Contexts reflecting the road and traffic conditions were then not seriously treated as a way to resolve the optimal routing problems based on distance-based route planning, because this kind of information does not have much significant impact on traffic routing until a a complex traffic situation arises. Further, it was also not easy to take into full account the traffic contexts for resolving optimal routing problems because predicting the dynamic traffic situations was regarded a daunting task. However, with rapid increase in traffic complexity the importance of developing contexts reflecting data related to moving costs has emerged. Hence, this research proposes a framework designed to resolve an optimal route planning problem by taking full account of additional moving cost such as road traffic cost and weather cost, among others. Recent technological development particularly in the ubiquitous computing environment has facilitated the collection of such data. This framework is based on the contexts of time, traffic, and environment, which addresses the following issues. First, we clarify and classify the diverse contexts that affect a vehicle's velocity and estimates the optimization of moving cost based on dynamic programming that accounts for the context cost according to the variance of contexts. Second, the velocity reduction rate is applied to find the optimal route (shortest path) using the context data on the current traffic condition. The velocity reduction rate infers to the degree of possible velocity including moving vehicles' considerable road and traffic contexts, indicating the statistical or experimental data. Knowledge generated in this papercan be referenced by several organizations which deal with road and traffic data. Third, in experimentation, we evaluate the effectiveness of the proposed context-based optimal route (shortest path) between locations by comparing it to the previously used distance-based shortest path. A vehicles' optimal route might change due to its diverse velocity caused by unexpected but potential dynamic situations depending on the road condition. This study includes such context variables as 'road congestion', 'work', 'accident', and 'weather' which can alter the traffic condition. The contexts can affect moving vehicle's velocity on the road. Since these context variables except for 'weather' are related to road conditions, relevant data were provided by the Korea Expressway Corporation. The 'weather'-related data were attained from the Korea Meteorological Administration. The aware contexts are classified contexts causing reduction of vehicles' velocity which determines the velocity reduction rate. To find the optimal route (shortest path), we introduced the velocity reduction rate in the context for calculating a vehicle's velocity reflecting composite contexts when one event synchronizes with another. We then proposed a context-based optimal route (shortest path) algorithm based on the dynamic programming. The algorithm is composed of three steps. In the first initialization step, departure and destination locations are given, and the path step is initialized as 0. In the second step, moving costs including composite contexts into account between locations on path are estimated using the velocity reduction rate by context as increasing path steps. In the third step, the optimal route (shortest path) is retrieved through back-tracking. In the provided research model, we designed a framework to account for context awareness, moving cost estimation (taking both composite and single contexts into account), and optimal route (shortest path) algorithm (based on dynamic programming). Through illustrative experimentation using the Wilcoxon signed rank test, we proved that context-based route planning is much more effective than distance-based route planning., In addition, we found that the optimal solution (shortest paths) through the distance-based route planning might not be optimized in real situation because road condition is very dynamic and unpredictable while affecting most vehicles' moving costs. For further study, while more information is needed for a more accurate estimation of moving vehicles' costs, this study still stands viable in the applications to reduce moving costs by effective route planning. For instance, it could be applied to deliverers' decision making to enhance their decision satisfaction when they meet unpredictable dynamic situations in moving vehicles on the road. Overall, we conclude that taking into account the contexts as a part of costs is a meaningful and sensible approach to in resolving the optimal route problem.

• Korean Journal of Psychosomatic Medicine
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• v.8 no.1
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• pp.20-30
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• 2000

Objective : This study was designed to investigate the frequencies and the relation of stressful life events and health problems and evaluate the influence of stressful life events on the physical symptoms and anxiety in adolescents. Method : Newcomb's 39-item life-event questionnaire and Newcomb's 19-item health problems questionnaire were administered to 475 adolescents. The frequencies of stressful life events and health problems which had actually occurred to them during the previous 12 months were investigated. Items of stressful life events were classified in 8 dimensional scaling factors(Family/parents, Accident/Illness, Sexuality, Autonomy, Deviance, Relocation, Distress, Items not in scales) and items of health problems were classified in 5 health problems(General, Heart and Lung, Nervous system, Anxiety, Psychosomatic symptoms) and the correlation between them was analyzed. Result : 1) The average number of events occurring during the past year for the 475 adolescents is 3(7.7%). The most frequent item of stressful life events was 'Thought about suicide' and dimensional factors of "Distress" and "Autonomy" were the most frequent life events in multidimensional sacling analysis. There were more factors of "Family/Illness" and " Autonomy" in male, while there was more factor of "Distress" in female. There were more factors of "School violence" and "Deviance" in younger students, while there were more factors of "Sexuality" and "Autonomy" in older students. 2) The most frequent item of health problem was 'excessive fatigue' and "anxiety" was most frequent health problem in multidimensional scaling analysis. There were more health problems in female than those in male. The higher grades the students became, the more health problems they have reported. 3) There was significant relationship between 7 factors of stressful life events except one factor of "Relocation" and 5 health problems. Conclusions : These findings suggest that as adolescents grow older, they are engaging in more controllable behaviors related to autonomy and sexuality and at the same time are experiencing increased difficulty with distressful or discomforting events, and their stressful life events are significantly related to decreased health and psychological functiong.

• Journal of Korean Home Economics Education Association
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• v.21 no.3
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• pp.1-28
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• 2009

The purpose of this research was to provide the information needed for improving the elderly housing education and the elderly housing contents of Technology and Home Economics textbook. Thus, the elderly housing contents of current Technology and Home Economics textbook were categorized. Then, a total of 233 teachers were surveyed to examine their importance perception on the elderly housing contents. Elderly housing contents were grouped into S categories, each of which was named 'safety and safety management', 'room plan for the elderly', 'shrinking stage in family life cycle and dependency stage in housing life cycle','a house for 3-generation extended family', and 'universal design'. Teachers' importance perception was generally high for 'safety and safety management' and especially for 'safety and safety management' of bathroom(protection against slippery floor, safety bar, the appropriate position and height of shower, bathtub, and wash stand) ; the basic guidelines of 'room plan for the elderly'(emergency call, closely located bathroom, flat and non-slippery floor) ; the general guidelines during shrinking stage in family life cycle and dependency stage in housing life cycle'(protection equipments against safety accident, emergency call, flat and non-slippery floor) ; independent life among 3-generation extended family members(bathroom for the elderly, space plan for independent life among extended family members) ; the basic design guidelines of universal design(safety bar in bathroom, flat floor) and the guidelines of universal design which were especially helpful for wheelchair users(enough empty space in front of door and in corridor, wide door and corridor). Recommendations for the elderly housing education and the elderly housing contents of Technology and Home Economics textbook were that 'emergency call','safety bar in bathroom' and 'flat and non-slippery floor' were the most basic guidelines for elderly housing; that 'enough empty space in front of door and in corridor', 'wide door and corridor', 'low and wide steps', 'ramp for wheelchair users' and 'D-type or lever-type door handle' were most recommendable guidelines for universal design; that 'need for elderly housing', 'types of elderly housing', 'alternatives and choices of dependency stage in housing life cycle' and 'house plans for shrinking stage in family life cycle' were required guidelines for increasing elderly-only family.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.12
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• pp.5684-5691
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• 2011

The purpose of this study is to examine effects of constraint-induced movement therapy(CIMT) and/or cognitive-perceptual training(CPT) on the change of hand function in cerebrovascular accident(CVA) patients and to evaluate the change in the amount and quality of use of the affected upper extremity in performing daily living tasks. The subjects of study were 10 patients who had been under rehabilitation for more than three months after CVA onset. They were all determined as mild cognition impairment according to NCSE or MVPT test. For CIMT group, to restrict the movement of the unaffected hand the subjects had been worn modified resting arm-splint in daytime for 4 weeks. For CIMT+CPT group, the subjects were performed CPT with CIMT and control group had been under conventional occupational therapy for the same period. CIMT+CPT group showed significant improvement in simulated feeding, lifting large light objects, and lifting large heavy objects of Jebsen-Taylor Hand Function Test. CIMT group also showed significant improvement compared with control group. The mean changes of the amount of use(AOU) of the affected arm had a statistically significant difference among groups (p<.05). While CIMT+CPT group had the biggest change in the quality of movement(QOM) of upper extremity of the affected side, CTL group showed the smallest change. Both CIMT and CIMT+CPT groups had statistically significant difference in the change in the quality of movement in upper extremity of affected side with CTL group(p<.05), but there was not significant difference between CIMT group and CIMT+CPT group. CIMT performed to the patients of stroke, with mild impairment in cognitive perceptual abilities showed the improvement in hand movement and AOU and QOM of upper extremity in the affected side and the combination of CIMT with CPT showed synergic effects.

• Sleep Medicine and Psychophysiology
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• v.12 no.1
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• pp.32-38
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• 2005

Objectives: Obstructive sleep apnea syndrome (OSAS) has drawn increasing attention as medical community has become to be aware of its co-morbidities and complications, especially cardiovascular complications and excessive daytime sleepiness with accident proneness. As of now, polysomnography is the standard tool to diagnose sleep apnea and estimate the treatment validity. However, its being rather expensive and inconvenient, alternate diagnostic tools have been proposed including wrist actigraphy. So far, actigraphies have been adopted usefully to field-survey sleep apnea prevalence. In this study, we attempted in a sleep laboratory setting to assess the supplemental value of actigraphy in diagnosing OSAS. Methods: This study was done at the Division of Sleep Studies, the Seoul National University Hospital. Thirty-seven clinically suspected cases of OSAS underwent the one-night polysomnography, simultaneously wearing an actigraphy on non-dominant wrist. We analyzed the data of 27 polysomnographically-proven OSAS patients (male：female 20： 7；age $47.6{\pm}12.9$ years old；age range 23 to 72 years) with no other sleep disorders. We calculated RDI (respiratory disturbance index) from the polysomnography data and FI (fragmentation index) from the actigraphy data. Pearson correlation was calculated in order to compare FI with RDI and to evaluate the supplemental diagnostic value of the actigraphy. Results: Mean total sleep time on polysomnography was $401.4{\pm}57.8\;min$ (range of 274.0 to 514.1 min). Mean RDI was $21.7{\pm}20.4/hour$. Mean FI was $21.9{\pm}13.0/hour$. RDI and FI showed significant correlation (r=0.55, p<0.01). Conclusions: Wrist actigraphy in OSAS patients generates a comparable outcome to polysomnography, in measuring the nocturnal sleep fragmentation. The actigraphy could be used supplementally in inpatients, outpatients, and field survey subjects, if polysomnography is unavailable or impossible. In follow-ups related with nasal CPAP (continuous positive airway pressure), upper airway surgery, and oral appliance in OSAS patients, the actigraphy might play a more dominant role in the future.

• Journal of Legislation Research
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• no.53
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• pp.593-631
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• 2017

Like the technological competition of each country around commercialization of Autonomous Vehicles(the rest is 'AV'), legalizations are also in a competition. However, in the midst of this competition, the Ethik-Kommission Automatisiertes und vernetztes Fahren of Germany has recently introduced 20 guidelines. This guideline is expected to serve as a milestone for future AV legislations. In this paper, I have formulated a new legislative proposal that will incorporate the main content presented by the Ethik-Kommission. The structure is largely divided into general rules of purpose and definition, chapter on types of AV and safety standards, registration and inspection, maintenance, licenses for AV, driver's obligations, insurance and accident responsibilities, roads and facilities, traffic system, and chapter on penalties. The commercialization of AV in Korea seems to be in a distant future, and it is possible to pretend that it is not necessary to prepare legal systems. But considering our reality, leading legislation may be necessary. In this paper, I have prepared individual legislative proposals based on the essential matters based on the criminal responsibility in case of AV car accidents. To assure the safety of AV, AV and mode of operation were defined for more clear interpretation and application of law, and basic safety standards for AV were presented. In addition, the obligation of insurance and the liability for damages were defined, and the possibility of immunity from the criminal responsibility was examined. Furthermore, I have examined the penalties for penalties such as hacking in order to secure the effectiveness of the Act. Based on these discussions, I have attempted the 'Autonomous Vehicles Act', which aims to provide a basis for new discussions to be held on the basis of various academic fields related to the operation of AV and related industries in the future. Although there may be a sense of unurgency in time, the automobile industry needs time to prepare for the regulation of the AV ahead of time. And a process of public debate is also needed for the ecosystem of healthy AV industry.

• Journal of Intelligence and Information Systems
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• v.16 no.3
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• pp.99-120
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• 2010

Due to the wide spread of customers' frequent access of non face-to-face services, there have been many attempts to improve customer satisfaction using huge amounts of data accumulated throughnon face-to-face channels. Usually, a call center is regarded to be one of the most representative non-faced channels. Therefore, it is important that a call center has enough agents to offer high level customer satisfaction. However, managing too many agents would increase the operational costs of a call center by increasing labor costs. Therefore, predicting and calculating the appropriate size of human resources of a call center is one of the most critical success factors of call center management. For this reason, most call centers are currently establishing a department of WFM(Work Force Management) to estimate the appropriate number of agents and to direct much effort to predict the volume of inbound calls. In real world applications, inbound call prediction is usually performed based on the intuition and experience of a domain expert. In other words, a domain expert usually predicts the volume of calls by calculating the average call of some periods and adjusting the average according tohis/her subjective estimation. However, this kind of approach has radical limitations in that the result of prediction might be strongly affected by the expert's personal experience and competence. It is often the case that a domain expert may predict inbound calls quite differently from anotherif the two experts have mutually different opinions on selecting influential variables and priorities among the variables. Moreover, it is almost impossible to logically clarify the process of expert's subjective prediction. Currently, to overcome the limitations of subjective call prediction, most call centers are adopting a WFMS(Workforce Management System) package in which expert's best practices are systemized. With WFMS, a user can predict the volume of calls by calculating the average call of each day of the week, excluding some eventful days. However, WFMS costs too much capital during the early stage of system establishment. Moreover, it is hard to reflect new information ontothe system when some factors affecting the amount of calls have been changed. In this paper, we attempt to devise a new model for predicting inbound calls that is not only based on theoretical background but also easily applicable to real world applications. Our model was mainly developed by the interactive decision tree technique, one of the most popular techniques in data mining. Therefore, we expect that our model can predict inbound calls automatically based on historical data, and it can utilize expert's domain knowledge during the process of tree construction. To analyze the accuracy of our model, we performed intensive experiments on a real case of one of the largest car insurance companies in Korea. In the case study, the prediction accuracy of the devised two models and traditional WFMS are analyzed with respect to the various error rates allowable. The experiments reveal that our data mining-based two models outperform WFMS in terms of predicting the amount of accident calls and fault calls in most experimental situations examined.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.4
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• pp.327-339
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• 2022

The purpose of this study is to present the effective smoke control flow rate and mode for securing safety through quantitative risk assessment according to the smoke control flow rate and mode (supply or exhaust) of the platform when a train fire occurs at the subway platform. To this end, a fire outbreak scenario was created using a side platform with a central staircase as a model and fire analysis was performed for each scenario to compare and analyze fire propagation characteristics and ASET, evacuation analysis was performed to predict the number of deaths. In addition, a fire accident rate (F)/number of deaths (N) diagram (F/N diagram) was prepared for each scenario to compare and evaluate the risk according to the smoke control flow rate and mode. In the ASET analysis of harmful factors, carbon monoxide, temperature, and visible distance determined by performance-oriented design methods and standards for firefighting facilities, the effect of visible distance is the largest, In the case where the delay in entering the platform of the fire train was not taken into account, the ASET was analyzed to be about 800 seconds when the air flow rate was 4 × 833 m³/min. The estimated number of deaths varies greatly depending on the location of the vehicle of fire train, In the case of a fire occurring in a vehicle adjacent to the stairs, it is shown that the increase is up to three times that of the vehicle in the lead. In addition, when the smoke control flow rate increases, the number of fatalities decreases, and the reduction rate of the air supply method rather than the exhaust method increases. When the supply flow rate is 4 × 833 m³/min, the expected number of deaths is reduced to 13% compared to the case where ventilation is not performed. As a result of the risk assessment, it is found that the current social risk assessment criteria are satisfied when smoke control is performed, and the number of deaths is the flow rate 4 × 833 m³/min when smoke control is performed at 29.9 people in 10,000 year, It was analyzed that it decreased to 4.36 people.

• Journal of Korea Entertainment Industry Association
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• v.13 no.7
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• pp.361-373
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• 2019

Falls are a threat to the physical health of the elderly as well as to their overall quality of life. The purpose of this study was to identify which type of exercise is effective for improving the balance of the elderly, and to obtain the basic data for developing the falls prevention exercise intervention program for the elderly. We compared to the differential effects between rhythmic step exercise and core muscle strengthening exercise in terms of functional balance test and self-reported balance test. Women older than 65 years and under 80 years of age were assigned to one of the step exercise group(21), core muscle exercise group(20), and control group(21), and for 8 weeks, twice per week, 20-30 minutes of exercise were treated. All participants performed one foot static balance test with open and closed eyes. And they responded to self-reported balance test, such as Fall Efficacy Scale(FES) and Activities-specific Balance Confidence(ABC) Scale. The results of statistical analysis are summarized as follows. First, rhythmic stepping exercise was more effective in improving functional balance than core muscle strengthening exercise. In particular, the effect of step exercise was obvious in the one-foot static balance test with open eyes. Second, the self-reported balance test showed better step exercise than core muscle exercise. Specifically, rhythmic step exercise was more effective in enhancing fall efficacy than core muscle exercise. In conclusion, the rhythmic step exercise was more effective in improving the balance ability of the elderly than the core muscle exercise. The rhythmic step exercise is more related to the lower extremity muscles, and especially since the rhythmic step exercise is performed in various ground changes, it seems to have a high similarity to the fall occurrence situation. For future research, we recommended the development of task-oriented ankle proprioceptive exercise intervention program and exercise equipment based on the specific motion situation in which the fall accident occurs in the elderly.

• Journal of Navigation and Port Research
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• v.40 no.4
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• pp.197-205
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• 2016

Our country, which relies on maritime transport a majority of import and export trade volume and faced with unexpected accidents, it is difficult to operate the normal function of container terminal. It also caused by reliability issue raised is likely to be given a blow to the new volumes to attract and maintain existing volumes. Under this views, the container terminal is a situation that highlights the role of the harbor workers and cope with aggressive work to provide the best quality services to customers 365 days. On these grounds, the heavy work burden is passed on to the harbor workers and caused accidents every year. The study was analyzed the safety status of the container terminal under the real following the conditions as disaster status analysis, insufficient safety training circumstances and safety training from 2012 year to 2015 in the target current K.Y terminal. As a result of equipments safety training analysis, it shows that 2012 year happened 45 cases and 31 cases in 2013 year until not practicing the training over the Gantry Crane equipment. One hand 23 cases took place in 2014 while preparation training and the other intensive training period of 2015, 8 cases occurred. it shows that 2012 year happened 13 cases and 19 cases in 2013 year until not practicing the training over the Transfer Crane equipment. One hand 12 cases took place in 2014 while preparation training and the other intensive training period of 2015, 8 cases occurred. it shows that 2012 year happened 9 cases and 9 cases in 2013 year until not practicing the training over the Yard Tractor equipment. One hand 9 cases took place in 2014 while preparation training and the other intensive training period of 2015, 4 cases occurred. Because safety training of the container terminal was given to greatly impact on the mandatory safety training, self-educational enforcement and specified equipments safety training, hence the container terminal is to strengthen the safety education to prevent accidents in advance.