• The Transactions of the Korea Information Processing Society
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• v.6 no.2
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• pp.385-395
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• 1999

Video-On-demand system provides electronic video rental services from remote video servers on a broadband communication networks. When we assume some situation that serve the same video stream by batching, each time single video stream became available at server-end side, we face the problem that what video stream to be scheduled at what time instant. Hence, in order to manage the resource bandwidth which is different at each stream, the policy of channel allocation became important factor. In this work, we proposed three type of scheduling policies with queueing, as are cumulative Waiting Time(CWT), Mean Waiting Time(MWT) and Predictable Popular Factor(PPF). While CWT policy is good for popular video, MWT policy was good for non-popular video. Also, we know that PPT policy has some fairness for average wait time and reneging rate of user requests.

• Journal of the Korean Society of Clothing and Textiles
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• v.43 no.3
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• pp.405-415
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• 2019

This study examined the physiological and psychological effects of wearing a winter cap at rest in a cold environment. Seven older males participated in two separate trials: wearing a winter cap (CAP) and non-wearing a winter cap (CON). The experiment was conducted for 60 min in a climatic chamber (air temperature $7.8{\pm}0.3^{\circ}C$ with $43{\pm}2%RH$) with sedentary posture. Microclimate temperature at the vertex of the head was $6.88^{\circ}C$ higher in CAP compared to CON (p<.01). Microclimate humidity at the vertex was lower in CAP than in CON only during the last 5 min (p<.01). Skin temperature at the forehead in CAP was higher than in CON (p<.01). During the last 5 min, rectal temperature was higher in CAP than that in CON (p<.05). Unlike CAP, the heart rate in CON during the last 5 min decreased significantly compared to the initial 5 min (p<.05). Subjects also felt less cold on the head/face in CAP than that in CON (p<.01). The results indicate that wearing a cap for elderly males positively affected body temperature regulation and cardiovascular response in cold environments. The importance of wearing warm hats for elderly males in winter should be emphasized.

• Archives of Plastic Surgery
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• v.46 no.5
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• pp.426-432
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• 2019

Background The mandible is an important structure that is located in the lower third of the face. Large mandibular defects after tumor resection cause loss of its function. This study assessed the outcomes and tumor recurrence after immediate mandibular reconstruction using a free fibula osteocutaneous flap following radical resection of ameloblastoma. Methods This is a retrospective non-randomized study of outcomes and tumor recurrence of all patients diagnosed with mandibular ameloblastoma from August 1997 until August 2017 (20 years) requiring free fibula osteocutaneous flap reconstruction at a single institution. The patients were identified through an electronic operative database; subsequently, their medical records and photo documentation were retrieved. Results Twenty-seven patients were included in this study. Eighteen patients were male, while nine were female. The majority of the patients (48.1%) were in their third decade of life when they were diagnosed with ameloblastoma. All of them underwent radical resection of the tumor with a surgical margin of 2 cm (hemimandibulectomy in cases with a large tumor) and immediate mandibular reconstruction with a free fibula osteocutaneous flap. Two patients required revision of a vascular anastomosis due to venous thrombosis postoperatively, while one patient developed a flap recipient site infection. The flap success rate was 100%. There was no tumor recurrence during a mean follow-up period of 5.6 years. Conclusions Mandibular ameloblastoma should be treated with segmental mandibulectomy (with a surgical margin of 2 cm) to reduce the risk of recurrence. Subsequent mandibular and adjacent soft tissue defects should be reconstructed immediately with a free fibula osteocutaneous flap.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.439-445
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• 2021

Low-cost, ultra-high-speed cameras, made possible by the development of image sensors and small displays, can be very useful in image processing and pattern recognition. This paper introduces an algorithm that corrects irregular lighting from a high-speed image that is continuously input with a slight time interval, and which then obtains an exposed skin color region that is the area of interest in a person from the corrected image. In this study, the non-uniform lighting effect from a received high-speed image is first corrected using a frame blending technique. Then, the region of interest is robustly obtained from the input high-speed color image by applying an elliptical skin color distribution model generated from iterative learning in advance. Experimental results show that the approach presented in this paper corrects illumination in various types of color images, and then accurately acquires the region of interest. The algorithm proposed in this study is expected to be useful in various types of practical applications related to image recognition, such as face recognition and tracking, lighting correction, and video indexing and retrieval.

• The Journal of the Korea Contents Association
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• v.22 no.10
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• pp.261-270
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• 2022

The changing nature of work suggests that people may face the prospect of a career choice including of paid employment, non-work and self-employment, of which the latter implies scope for entrepreneurial activity. The goal of this study is to view the impact of entrepreneurial competency, social support, entrepreneurial role model as an affect to increase the entrepreneurial intention of adult with the purpose of a second career choice. Also, the mediating effect of entrepreneurial mentor is verified. As research methodology, a research model and a hypothesis were set based on prior research and the research hypothesis was proven through a structured survey questionnaire. SPSS 24.0 was used for data analysis. Analysis results are as follows: First, out of entrepreneurial competency, job competency and funding capability had a positive effect on entrepreneurial intentions. Second, entrepreneurial role model had a positive effect on entrepreneurial intentions. Third, in the relationship between entrepreneurial competency, social support, entrepreneurial role model and entrepreneurship intentions, the mediating effect of mentor had significant job competency→mentor→entrepreneurship intention, funding capability→mentor→entrepreneurship intention, entrepreneurial role→mentor→entrepreneurship intention.

• Journal of the Korean Society of Safety
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• v.37 no.6
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• pp.118-127
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• 2022

This study analyzes the characteristics of occupational accidents of food delivery via motorcycle in terms of accident probability and work-days. Depending on their employment status, food-delivery workers were divided into "employed" workers (who work for restaurants) and "special-type" workers (who work for delivery platforms). Collected data include occupational accident-information during the last two years (1,468 cases for employed workers and 4,899 cases for special-type workers) and their risk information such as age, work experience, accident location, season of the accident, and weather conditions. The study finds that special-type workers had a significantly higher accident probability for the younger age group (80.8%), while employed workers had more accidents in both 20's or younger (34.9%) and 50's or older (25.4%). The number of work-days-lost was higher for special-type workers with less work experience, and it decreased with increasing work experience. Moreover, the chance for accidents was higher at night time (55%) than for day time (45%) for special-type workers as well as for employed workers. The number of work-days-lost was higher in foreign workers (180.79 days) than in Korean workers (121.44 days). Accident probability (30.7%) and work-days-lost (136.2 days) was higher in winter than in other seasons. In addition, accidents-per-day was higher on snowy days (12.7 cases per day) than rainy (8.1) and windy days (7.1). In addition, it was found that deadly accidents mainly caused injuries to face, head, and chest, while non-deadly accidents affected mainly the legs and feet. This study enables the development of better policies to prevent accidents of food delivery workers.

• Journal of Electrochemical Science and Technology
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• v.15 no.1
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• pp.198-206
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• 2024

Given the high theoretical capacity (1,675 mAh g^-1) and the inherent affordability and ubiquity of elemental sulfur, it stands out as a prominent cathode material for advanced lithium metal batteries. Traditionally, sulfur was sequestered within conductive porous carbons, rooted in the understanding that their inherent conductivity could offset sulfur's non-conductive nature. This study, however, pivots toward a transformative approach by utilizing diatom shell (DS, diatomite)-a naturally abundant and economically viable siliceous mineral-as a sulfur host. This approach enabled the development of a sulfurlayered diatomite/S composite (DS/S) for cathodic applications. Even in the face of the insulating nature of both diatomite and sulfur, the DS/S composite displayed vigorous participation in the electrochemical conversion process. Furthermore, this composite substantially curbed the loss of soluble polysulfides and minimized structural wear during cycling. As a testament to its efficacy, our Li-S battery, integrating this composite, exhibited an excellent cycling performance: a specific capacity of 732 mAh g^-1 after 100 cycles and a robust 77% capacity retention. These findings challenge the erstwhile conviction of requiring a conductive host for sulfur. Owing to diatomite's hierarchical porous architecture, eco-friendliness, and accessibility, the DS/S electrode boasts optimal sulfur utilization, elevated specific capacity, enhanced rate capabilities at intensified C rates, and steadfast cycling stability that underscore its vast commercial promise.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.35 no.6
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• pp.360-367
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• 2013

Purpose: The purpose of this study was to perform three-dimensional (3D) assessment of facial soft tissue in patients with skeletal Class III and mandibular asymmetry after orthognathic surgery. Methods: Samples consisted of 3D facial images obtained from five patients with A point-nasion-B point angle less than 2 degrees, and more than 5 mm of menton deviation. All patients had been treated at Gangneung-Wonju National University Dental Hospital from 2009 to 2012. They had undergone orthognathic surgery of Lefort I, and sagittal split osteotomy for correction of skeletal deformity, and orthodontic treatment. Facial scanning was performed before treatment (T1) and post-surgical orthodontic treatment (T2). Linear and angle variables of soft tissue landmarks, antero-posterior facial depth, and facial volume were measured. Results: No significant differences in width of the alar base, mouth width, and nasal canting were observed between T1 and T2. However, lip deviation, menton deviation, alar canting, lip canting, and menton deviation angle were significantly reduced at T2. Antero-posterior facial depth on the axial plane parallel to the left cheilion was significantly reduced on the deviated side and significantly increased on the non-deviated side at T2. Volume of the lower lateral and lower medial parts of the face was reduced on the deviated side, and volume of upper lateral and lower lateral parts on the non-deviated side was significantly increased at T2. Conclusion: After orthognathic surgery, facial asymmetry of soft tissue was improved following skeletal changes, especially the mandibular region. Although the length of the alar base and mouth width did not change, lip and soft tissue menton were displaced to the medial side after treatment. Facial depth also became symmetric after treatment. Facial volume showed a decrease on the lower part of the deviated side and that on lateral parts of the non-deviated side showed an increase after treatment.

• Journal of the Korean earth science society
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• v.45 no.3
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• pp.203-213
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• 2024

This study aimed to investigate the seasonal patterns of multiple bar formation in summer and flattening in winter on the macrotidal Sinduri beach in Taean, and to understand the processes their formation and subsequent flattening. Beach profiling has been conducted regularly over the last four years using a VRS-GPS system. Surface sediment samples were collected seasonally along the transectline, and grain size analyses were performed. Tidal current data were acquired using a TIDOS current observation system during both winter and summer. The Sinduri macrotidal beach consists of two geomorphic units: an upper high-gradient beach face and a lower gentler sloped intertidal zone. High berms and beach cusps did not develop on this beach face. The approximately 400-m-wide intertidal zone comprises distinct 2-5 lines of multiple bars. Mean grain sizes of sand bars range from 2.0 to 2.75 phi, corresponding to fine sands. Mean sizes show shoreward coarsening trend. Regular beach-profiling survey revealed that the summer profile has a multi-barred morphology with a maximum of five bar lines, whereas, the winter profile has a non-barred, flat morphology. The non-barred winter profiles likely result from flattening by scour-and-fill processes during winter. The growth of multiple bars in summer is interpreted to be formed by a break-point mechanism associated with moderate waves and the translation of tide levels, rather than the standing wave hypothesis, which is stationary at high tide. The break-point hypothesis for multi-bars is supported by the presence of the largest bar at mean sea-level, shorter bar spacing toward the shore, irregular bar spacing, strong asymmetry of bars, and the 10-30 m shoreward migration of multi-bars.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.12
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• pp.1956-1964
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• 2009

Understanding ethical fashion consumers in Korea is essential for the expansion of the ethical fashion market. This study analyzed ethical consumers in Korea in an examination of the factors that influence ethical purchase behavior and attitudes. The differences between ethical fashion consumers and non-ethical fashion consumers were investigated using eight variables (perceived consumer effectiveness (PCE), self-direction, benevolence, universalism, social responsibility, perceived behavioral control, face saving, and group conformity). Data were collected by means of a questionnaire through both on-line and off-line surveys from April 20 to June 7, 2009. Only the respondents knowledgeable of ethical products or ethical consumption were asked to complete the questionnaire. A total of 494 samples were used for analyses. Using independent samples t-test, the differences in each variable between two groups were examined. There were significant differences between ethical fashion consumers and non-ethical fashion consumers in attitudes toward ethical consumption behavior, behavioral intention, PCE, self-direction, universalism, social responsibility, and face saving variables. The factors influencing attitude and behavior intention were investigated by step-wise regression analyses. For ethical fashion consumers, the attitudes to ethical consumption behavior were largely influenced by PCE and benevolence. Social responsibility was the most predictable variable in guiding behavioral intention. Behavioral intention was also influenced by benevolence and attitude. Group conformity was found to be negatively correlated with behavioral intention. The findings of this study provide significant guidance for marketers of ethical fashion products. This study is the start of ethical fashion consumer research in Korea and can develop into variable subfields in the future.