• Journal of Korean Port Research
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• v.14 no.1
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• pp.66-75
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• 2000

From the traffic analysis, and model constructions and verifications for speed prediction on the freeway ramp junctions with 70mph speed limit, the following results were obtained : ⅰ) The traffic flow distribution showed a big difference depending on the time periods. Especially, more traffic flows were concentrated on the freeway junctions in the morning peak period when compared with the afternoon peak period. ⅱ) The occupancy distribution was also shown to be varied by a big difference depending on the time periods. Especially, the occupancy in the morning peak period showed over 100% increase when compared with the 24hours average occupancy, and the occupancy in the afternoon peak period over 25% increase when compared with the same occupancy. ⅲ) The speed distribution was not shown to have a big difference depending on the time periods. Especially, the speed in the morning peak period showed 10mph decrease when compared with the 24hours'average speed, but the speed did not show a big difference in the afternoon peak period. ⅳ) The analyses of variance showed a high explanatory power between the speed predictive models(SPM) constructed and the variables used, especially the upstream speed. ⅴ) The analysis of correlation for verifying the speed predictive models(SPM) constructed on the ramp junctions were shown to have a high correlation between observed data and predicted data. Especially, the correlation coefficients showed over 0.95 excluding the unstable condition on the diverge section. ⅵ) Speed predictive models constructed were shown to have the better results than the HCM models, even if the speed limits on the freeway were different between the HCM models and speed predictive models constructed.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1999.10a
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• pp.111-121
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• 1999

From the traffic analyses, and model constructions and verifications for speed prediction on the freeway ramp junctions with 70mph speed limit, the following results obtained: ⅰ) The traffic flow distribution showed a big difference depending on the time periods. Especially, more traffic flows were concentrated on the freeway junctions in the morning peak period when compared with the afternoon peak period. ⅱ) The occupancy distribution was also shown to be varied by a big difference depending on the time periods. Especially, the occupancy in the morning peak period showed over 100% increase when compared with the 24hours average occupancy, and the occupancy in the afternoon peak period over 25% increase when compared with the same occupancy.ⅲ) The speed distribution was not shown to have a big difference depending on the time periods. Especially, the speed in the morning peak period shown 10mph decrease when compared with the 24hours' average speed, but the speed did not show a big difference in the afternoon peak period.ⅳ) The analyses of variance showed a high explanatory power between the speed predictive models(SPM) constructed and the variables used, especially the upstream speed. ⅴ) The analysis of correlation for verifying the speed predictive models(SPM) constructed on the ramp junctions were shown to have a high correlation between observed data and predicted data. Especially, the correlation coefficients showed over 0.95 excluding the unstable condition on the diverge sectionⅵ) Speed predictive models constructed were shown to have the better results than the HCM models, even if the speed limits on the freeway were different between the HCM models and speed predictive models constructed.

• Journal of KIISE:Information Networking
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• v.27 no.3
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• pp.301-314
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• 2000

As the number of World Wide Web (Web) users grows, Web traffic continues to increase at an exponential rate. Currently, Web traffic is one of the major components of Internet traffic. Also, high bandwodth usage due to Web traffic is observed during peak periods while leaving bandwidth usage idle during off-peak periods. One of the solutions to reduce Web traffic and speed up Web access is through the use of Web caching. Unfortunately, Web caching has limitations for reducing network bandwidth usage during peak periods. In this paper, we focus our attention on the use of a prefetching algorithm for reducing bandwidth during peak periods by using off-peak period bandwidth. We propose a statistical, batch, proxy-side prefetching scheme that improves cache hit rate while only requiring a small amount of storage. Web objects that were accessed many times in previous 24 hours but would be expired in the next 24 hours, are selected and prefetched in our scheme. We present simulation results based on Web proxy and show that this prefetching algorithm can reduce peak time bandwidth using off-peak bandwidth.

• Safety and Health at Work
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• v.15 no.1
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• pp.102-109
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• 2024

Background: In today's modern world, longer working hours, shift work, and working at night have become major causes of the disruption of our natural circadian rhythms. This study aimed to investigate the effects of the type of shift work (rotating vs. fixed day), duty period (on-duty vs. off-duty), and working period within each shift (nighttime vs. daytime) on the circadian rhythm characteristics of nurses who provide direct patient care. Methods: This cross-sectional study used a purposive sampling method. Cosinor analysis was applied to analyze the actigraphy data of nurses providing direct patient care for seven consecutive days. The linear mixed effects model was then used to determine any variances between shift type, duty period, and working period within each shift for the nurses. Results: The mesor value did not differ according to nurses' shift type, duty period, and working period within each shift. The amplitude was statistically higher in on-duty nurses and in daytime working hours. The acrophase was significantly delayed in nighttime working hours. As well as nurses in rotating shift had experience. Conclusion: Our findings revealed that the peak activity of nurses occurs significantly later at night while working and nurses working during nighttime hours may have a weaker or less distinct circadian rhythm. Thus, this study suggests that limits be placed on the number of rotating nighttime shifts for nurses.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.1 no.1
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• pp.69-76
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• 1994

This study was designed and undertaken to find out the effectiveness of VAS for evaluation of general anesthetic postoperative pulmonary-function. We compared the degree of perceived pulmonary function recovery with peak expiratory flow at postoperative 72 hours of subjects. The subjects of this study were collected 38 patients who had received upper abdominal operation in St. Paul Hospital, Catholic University Medical College, and Kangnam Scared Heart Hospital and Kangdong Scared Heart Hospital, Hallym University. Data collection period was from June 15th, to August 7th, 1992. The degree of pulmonary recovery function was measured with peak expiratory at 72 hours postoperatively. The degree of perceived pulmonary function of the patient was measured with ten points visual analog scale at 72 hours postoperatively. Peak expiratory flow and visual analog score was analyzed with Pearson correlation. Peak expiratory flow was expressed as a ratio of preoperative value. The result was as follows : The recovery of pulmonary function and the degree of perceived pulmonary function of the patient at 72hours postoperatively was revealed high correlation (r=.84). The above result suggested that patients with general anesthetic upper abdominal surgery should evaluate recovery of pulmonary function making use of VAS. We know that VAS is very useful in postoperative patients. We perceived that VAS is to take up a positive attitude of patients. Nurse should furnish the nursing care objectively and scientifically to patients. As VAS was economic and simple, VAS should be adviced for wider application.

• Korean Journal of Ecology and Environment
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• v.56 no.4
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• pp.406-413
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• 2023

Captive breeding and reintroduction are crucial strategies for conserving endangered species populations. However, fish raised in predator-free environments, show a lack of recognition of predationrelated stimuli such as chemical and visual signals. It is critical to recognize chemical signals from injured conspecifics, also known as alarm signals, and the order or shape of predators to indicate the spread of predation risk in the habitat. We conducted a laboratory experiment to determine and adjust the optimal exposure period to induce appropriate anti-predator behavior response to different types of stimuli (Chemical, Visual and Chemical+Visual) for the endangered species Microphysogobio rapidus. Our results demonstrate that predator avoidance behavior varies depending on the types of stimuli and the duration of predation risk exposure. First, the results showed captive-breed M. rapidus show lack of response against conspecific alarm signal (Chemical cue) before the predation risk exposure period and tend to increase response over predation risk exposure time. Second, response to predator (visual cue) tend to peak at 48 hours cumulative exposure, but show dramatic decrease after 72 hours cumulative exposure. Finally, response to the mixed cue (Chemical+visual) tend to peak prior to the predation risk exposure period and show reduced response during subsequent exposure periods. This experiment confirms the lack of responsiveness to conspecific alarm signals in captive-bred M. rapidus and the need for an optimal nature behavior enhancement program prior to release of endangered species. Furthermore, responsiveness to predator visual signal peak at 48 hours cumulative exposure, suggest an optimal predation risk exposure period of up to 48 hours.

• Journal of Navigation and Port Research
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• v.30 no.5 s.111
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• pp.397-404
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• 2006

Gamcheon harbor was developed as a multipurpose port to mix processing functions of exclusive piers for bulk cargo such as marine products, domestic cargoes. Since the container terminal was opened in 1997, maximum $40,000\sim50,000$ DWT containership have been incoming and outgoing. However, bemuse the breakwater entrance in Gamcheon harbor is narrow and the crossed vessels are ever-present at breakwater front, marine accident danger is high that grasping traffic characteristics is required in reply. Therefore marine traffic characteristics were analyzed for Gamcheon harbor and Gamcheon approaching waters, included the track and traffic volumes of peak hours period in inbound/outbound and front sea area of the harbor in present.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.06b
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• pp.137-146
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• 2006

Gamcheon Harbor was developed as a multipurpose port to mix processing functions of exclusive piers for bulk cargo such as marine products. domestic cargo. Since the container terminal was opened in 1997. maximum $40,000{\sim}50,000$ DWT containership have been incoming and outgoing. However, because [he breakwater entrance in Gamcheon Harbor is narrow and the crossed passing of ship is ever-present at breakwater front, marine accident danger is high that grasping traffic characteristics is required in reply. Therefore marine traffic characteristics were analyzed for Gamcheon Harbor, included the track and traffic volumes of peak hours period in inbound/outbound and front sea area of the harbor in present.

• The Korean Journal of Zoology
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• v.10 no.2
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• pp.18-22
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• 1967

The routine entomological investigations were carried out in the areas of Kaejeon-Myon, OkkuGun, Cholla Pukdo province in 1964 and Sinchang-Myon, Asan Gun, Chungchong Namdo province in 1965, for the better understanding of the behavior of the anpheline mosquitoes especially of the population density , resting , feedign, and breeding habits. The results are as follows : 1. During the investigation , three species of anopheline mosquitoes were recorded ; Anopheles sinensis Wiedmann 1825, A, sineroides Yamada 1935, and A. yatsushiroensis Miyazaki 1951. A . yatsushiroensis Myiyasaki 1951, so far only recorded in Japan, was recorded for the first time in Korea in 1964 ; the site was Kaejong Myon, Okku Gun, Cholla Pukdo province. 2. Anopheles mosquitoes begin to appear from the middle of April and disappear in October. The date of mosquitoes collected by resting place collection in cow shed are three weeks ahead to the night time cow biting collection. 3. Resting places of anopheline mosquitoes are mainly in cow shed and outdoors which provides high humidity and shadow. 4. The population density of a. sinensis sows a peak in late June and early July in cow shed and by cow biting collection respectively, and another small peak in late August and early September. 5, . the biting activity at night is throughout the night from dusk to dawn, sharply decreasing just before dawn. The peak period was different in each months, 2100-2200 hours in June, 2300-2400 in July , 0300-0400 in August , and 2300-2400 in September. 6. The minimum temperature required for the mosquito's biting activity is 15 $^{\circ}C$ and the optimum is between 24-$25^{\circ}C$ : over $25^{\circ}C$ the activity is decreased. 7.A , sinensis appeared to be zoophilic in Sinchang area but 13 times anthrophophilic in Kaejong area than the former. 8. the light attraction of a. sinensis is significantly low in middle June and early August. The parous rate of A. sinensis caught by cow biting collection appeared higher after midnight (2400-0300 hours) with no relation to the peak period of biting activity by month.

• The Journal of Korean Medicine
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• v.28 no.4
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• pp.8-12
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• 2007

Objectives : This study aimed to investigate the circadian variation in stroke types, ischemic stroke subtypes, and Sasang constitutions. Methods : 295 patients with acute stroke within 14 days onset were included, who were admitted to Kyunghee Oriental Medical Center from October 2005 to May 2007. The stroke onset time was subdivided into four groups of 6-hour intervals in a day. Stroke types, ischemic stroke subtypes, and Sasang constitutions in four groups were examined. Results : Most ischemic stroke occurred between 6:01-12:00 hours (30.2%). For ischemic stroke subtypes, the peak period of small-vessel occlusion was between 6:01-12:00 hours (33.2%), large-artery atherosclerosis was most common between 12:01-18:00 hours (39.5%), and cardiac embolism was most frequent between 18:01-24:00 hours (50%). In terms of Sasang constitution, Soyeumin and Taeyeumin were most common between 6:01-12:00 hours (36.4% versus 41.5%, respectively), but the peak time of Soyangin was between 12:01-18:00 hours (35.2%). Conclusion :Most ischemic stroke events occurred in the mid-to-late morning hours in the present study and there was a circadian variation of onset in ischemic stroke subtypes and Sasang constitution.