• Journal of Information Technology Services
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• v.20 no.6
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• pp.83-95
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• 2021

In this study, various usage patterns were analyzed after establishing a data mart for micro mobility analysis based on the rental history of public bicycles in Seoul. Rental history data is origin-destination data that includes the rental location and time, and the return location and time. About 1500 rental locations were classified according to the characteristics of the location to create a 'station type' dimension. We also created a 'path type' dimension that displays whether the rental location and return location are the same. In addition, a derived variable called speed, which is obtained by dividing the distance used by the time used, is added, and through this, the characteristics of the riding area and the reason for the rental can be estimated. Meanwhile, administrative district link, administrative neighborhood link, and station type link were created to apply network analysis. Through this analysis, the roles and proportions of administrative districts, public facilities, and private facilities engaged in micro-mobility services were visualized. 49.9% of rentals occur at rental offices near transportation facilities, and half of them occur at rental offices near subway stations. The number of rentals during the evening rush hour is more than double that of the morning rush hour. When the path type is unidirectional, there is a fixed destination, so the distance and time used are short, and the movement speed tends to be high. In the case of round-trip, the purpose of use is exercise or leisure, so the distance and time used are long, and the movement speed is slow. It is expected that the results of the analysis can be used as reference materials for selecting new rental locations, providing convenient services for users, and developing user-specialized products.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.5
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• pp.1981-1987
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• 2013

$CO_2$ emissions of vehicles vary with vehicle's speeds. In addition, the speeds vary with road type, location, time and traffic volume. In this paper, the section in which a large quantity of $CO_2$ emissions per vehicle is exhausted is determined and analyzed with principal component analysis(PCA). In results of analysis, the principal components analysis were divided into two principal components. It had been identified that the main component was the time zone one which is able to explain each components' role. The first principal component could explain the role of a major component on $CO_2$ emissions per vehicle in the early morning and afternoon hour, respectively. The second principal component could explain the role of the component on $CO_2$ emissions per vehicle in the morning and afternoon peak hours, respectively. Therefore, the section in which a large quantity of $CO_2$ emissions per vehicle could be deterimined by PCA scores.

• Journal of Korean Academy of Nursing
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• v.21 no.2
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• pp.129-149
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• 1991

Circadian rhythm is entrained in the 24-hour time interval by periodic factors in the environment, known as zeitgeber. But most rotating work schedules are outside the range of the entrainment of the pacemaker timing the human circadian sleep - wake cycle. It has been postulated that physiological and emotional disturbances occur in most human functions when the circadian rhythm is disturbed. So application of circadian principles to the design of shift schedules can aid in maintaining the temporal integrity of the circadian system and thereby minimize for the shift worker any detrimental consequences of circadian disruption. This study was a quasi-experimental study to test the effect of shift intervals for the clinical nurse on the circadian rhythm. Twenty nurses newly employed in general units of two hospitals were selected as an experimental group and twelve college nursing students as a control group. Both groups were selected according to an established criteria using a purposive sampling technique. Ten subjects were assigned to a weekly shift group and another ten to a biweekly shift group engaged in a semi -continuous shift schedule(sunday off) with a backward direction, that is, morning -evening - night shift. The control group worked a morning shift for 42 days. Oral temperature rhythm, waking tim, sleep - wake cycle, fatigue, and mental performance were measured during the experimental period. The data collection period was from April 30, 1990 to June 10, 1990. MANOVA, paired t-test, ANOVA, and Student Newman Keuls method were used for statistical analysis. The results are summarized as follows. 1. Phase delay in the acrophase of temperature rhythm was shown according to the backward rotating shift. A complete adaptation to work on the night shift was achieved between the sixth and ninth day of the night shift. 2. There was no difference in either waking time or sleep- wake cycle according to the duration of the working day for every shift group. Significant difference was found in the waking time and the sleep -wake cycle for subjects on the morning, evening, and night shift in both of the shift groups(weekly shift group : λ＝0.121, p＜0.01, λ＝0.112, p＜0.01, biweekly shift group : λ＝0.116, p＜0.01, λ＝0.084, p＜0.01). 3. There was no difference in fatigue between the first working day and the last working day for the control group and for the biweekly shift group. In the weekly shift group, physical fatigue was significantly different for the first day and the sixth day of the night shift(t＝-2.28, p＜0.05). Physical fatigue and total fatigue on the first day of the night shift showed a significant difference among the control group, the weekly shift group, and the biweekly shift group(F＝5.79, p＜0.01, F＝4.56, p＜0.05). There was a significant difference between the shift groups and the control group(p＜0.05), Physical fatigue, neurosensory fatigue and total fatigue on the last day of the night shift showed a significant difference among the control group, the weekly shift group, and the biweekly shift group(F＝12.65, p＜0.01, F＝7.77, p＜0.01, F＝9.68, p＜0.01). There was a significant difference between the shift groups and the control group(p＜0.05). 4. No difference in mental performance was seen between the first day and the last day of work in each case. An arithmatic test on the first day of the night shift revealed a significant difference among the control group, the weekly shift group, and the biweekly shift group(F＝3.79, p＜0.05). There was a significant difference between the shift groups and the control group(p＜0.05) . The digital symbol substitution test and the arithmetic test on the last day of the night shift showed a significant difference among the control group, the weekly shift group, and the biweekly shift group(F＝3.68, p＜0.05, F＝5.55, p＜0.01), and both showed a significant difference between the shift groups and the control group(p＜0.05). Accordingly, this study showed that during night duty, the waking time, sleep- wake cycle, and fatigue increased and mental performance decreased compared with morning and evening duty. It was also found that the weekly shift group had a higher fatigue score on the sixth day of night duty as compared to the -first day, but the waking time, sleep- wake cycle, and mental performance revealed no difference for the duration of the night duty or between shift groups, and complete adaptation of temperature rhythm was achieved between the sixth and ninth day of night duty. It is possible to conclude from these results that for intermediate circadian type in a healthy young woman, a biweekly shift system is more compatible with the circadian timing system than weekly shift system.

• Journal of Environmental Health Sciences
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• v.27 no.1
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• pp.69-74
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• 2001

A study on temperature control of freezers & refrigerators in department stores and supermakets was conducted in Taegu are from July 15 through August 30 in order to determine how the temperature is effectively controled for food safety. Five departments and four supermarkets were selected randomly and fifty seven refrigerators and fifty nine freezers were inspected to observe temperature of thermometers and measure the temperature of the coolers by laser thermometer. The results are as follow; 1. Out of one hundred and sixteen coolers, eighty six (74.1%) were open type coolers and thirty (25.9%) were closed types (p<.05). 2. Twenty five (89.3%) of refrigerators and twenty three (82.1%) of freezers in department stores had thermometers and twenty seven refrigerators (93.1%) and twenty two (71%) of freezers in supermarkets had thermometers respectively (p<.01). 3. The measured temperatures of coolers increased in the afternoon to compared to the temperatures of them in the morning time (p<.01). The difference of temperatures of coolers between department stores and supermarkets was wider in the supermarkets and difference of temperatures of food items between refrigerators and freezers was wider in the refrigerators but the difference was not statistically significant. 4. The temperatures of forty four (84.6%) out of fifty two refrigerators within recommended ranges and those of forty two (93.3%) of forty five freezers higher than recommended ranges (p<.05).

• Archives of Plastic Surgery
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• v.32 no.2
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• pp.250-254
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• 2005

Burns due to epileptic seizures are commonly deep and usually require operative treatment. The purpose of this study is to identify the characteristics of burned epileptic patients that could lead to the development of preventive programs to reduce the incidence of burn injuries. We analyzed epidemiological data for 34 patients acutely burned due to epileptic seizure admitted retrospectively. There were 15 male and 19 female subjects. The age distribution was from 6 years to 70 years with the mean age of 42.7 years. Seizures usually occurred while carrying out daily domestic chores. Scalding burns were the most common(38.2%) and most burns were above deep second degree(94.1%). The most common seizure type was generalized tonic-clonic, followed by absence and complex partial. The seizure mostly occurred in the morning because the therapeutic blood level of antiepileptic drugs was decreased extremely at that time by stopping drug arbitrarily or taking inadequately. So more frequent follow-ups at the neurology outpatient clinics for epileptics should be strictly reinforced to maintain the adequate therapeutic blood levels of antiepileptic drugs and fire protective implements should be prepared in the house.

• Journal of Chest Surgery
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• v.20 no.2
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• pp.348-352
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• 1987

A 51 year-old male was admitted with the chief complaints of swallowing difficulty and pain on neck and upper chest for 2 months prior to admission: He was taken biopsy under esophagoscopy, and the result was squamous cell carcinoma. Preoperatively we studied the esophagogram and chest CT. On these, we found the main appreciable mass at midesophagus easily. But, we missed the upper cervical unexpected mass. So we performed the esophagectomy and lymph node dissection from upper clavicle level to the esophagogastric junction by thoracic approach as wide as possible, and cervical esophagostomy and feeding gastrostomy also. At that evening we reviewed the studied films in detail, and we found another mass lesion at C4-C6 level of cervical esophagus. We performed the 2nd operation e.g. cervical esophagectomy on next morning without hesitation. Between these two masses, there was almostly normally looking skip area grossly. The squamous cell carcinoma of the esophagus could be multicentric in character and may have skip area. But, we heard little reports until now. The two masses could be different in origin or be same probably by submucosal spreading. Anyway, it was an alarming case to the surgeon not to neglect the another possible lesions in squamous cell type. Postoperative course was uneventful, he took G-tube feeding with no problems on 7th postoperative day. Now he took the postoperative irradiation at out patient department.

• Journal of Environmental Science International
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• v.21 no.9
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• pp.1149-1162
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• 2012

The impact of a considerable increase in traffic volume on the emission and concentrations of air pollutants was investigated at three beaches (Haeundae (HB), Gwanganri (GB), and Songjeong (SB)) in Busan during beach opening period (BOP) in 2011. During the BOP, passenger car was the major vehicle type, followed by taxi, and van. CO was the major contributor of total air pollutant emissions followed by NOx, VOC, and $PM_{10}$. For the temporal variation of the emission of air pollutants during the BOP, it was generally the highest in the afternoon followed by the evening and morning, except for SB. For the spatial variation of their emission, it was the highest at GB followed by SB and HB. The emissions of air pollutants during the BOP were generally higher than those during the Non-BOP, except for HB. In contrast, the significant impact of the traffic volume increase on the concentrations of air pollutants at monitoring sites near the three beaches during the BOP were not found compared to the Non-BOP due to the significant distances between monitoring sites of air pollutants and monitoring sites of traffic volume at the beaches.

• Journal of Preventive Medicine and Public Health
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• v.7 no.2
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• pp.305-312
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• 1974

Studies on 66 industrial accidents happened in a battery manufacturing industry during a year of 1973 were carried out. The results obtained are follows, 1. Majority of employees of this industry was occupied by yong woman aged between 20-24. 2. Incidence rate, frequency rate and severity rate of the accidents was 36.8 per 1,000, 12.8 per 100,000 labour day and 0.3% respectively. Anual average days of lost due to accidents was 18.0 days. 3. Accidents happened more frequently in male than female, and happened most frequently in age between 30-34. 4. As to type of work, 47.9% of the accidents happened on hand operating workers. This was the same in both sex. 5. Accidents happened mainly during 2-3 hours latter from work starts in both morning and afternoon work, 6. 63.6% of the accidents happened on hands in both sexes and followed by lower extremities. 7 Surface wounds like as laceration, cut and abrasion were the main types of injury occupying 31.8% and followed by burn at 24.2%. 8. 54.5% of accidents needed 1-2 weeks to heal the injury and heavy injury needed more than 5 weeks was only 9.1%. 9. Accidents happened most frequently in employees who served between 2-3 years in this industry, but observing of sex difference. it was most frequent in male who served more than 4 years whereas less than 6 months in female.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.6
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• pp.515-520
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• 2012

A daylighting system includes three parts; light collector, light transformer and light distributor. A DBLP(Double blind light pipe) daylighting system consists of a double blind light collector, a mirror duct type light transformer and a prism film light pipe distributor. The double blinds for a light collection are used to track the sun's altitude and azimuth movements throughout the day. Behind both sets of blinds is the light transformer, which is based on a rectangular cone shaped light duct. The light transformer was designed to efficiently deliver the light into the light pipe within a 30 degree radial spread for the efficient light into the distributor. In this study, DBLP system efficiency was simulated, evaluated and optimized by Tracepro as a popular ray trace light design simulation program. The results indicated that DBLP system efficiency evaluated a maximum 22.4% in case of Spring/Fall season solar noon time. While the overall average system efficiency in the morning and afternoon is evaluated about 10%.

• Journal of Ginseng Research
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• v.19 no.1
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• pp.17-21
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• 1995

A study was designed to investigate the effectiveness of Korean Red Ginseng (ERG) as an oral agent for erectile dysfunction (EF), which was compared to that of placebo and trazodone. Patients who were believed to have EF of mild or non-organic etiologies, randomized into 3 groups to receive 600 mg KRG 3 times daily (group A), placebo (group B) and 25mg trazodone once a day after evening (group C). All agents were given orally. Ninety patients, composed of 30 in each group, were included and analyzed only when clinical follow-up could be achieved at the end of the study for at least 3 months. There were no significant differences(p>0.05) between each group in mean age (43.7 years), duration of EF (5.8 years), the state of marriage (married : 80 patients) and duration of marriage (18.2 years). In group A, the parameters such as rigidity and tumescence on erection, early detumescence, libido and patient's satisfaction were significantly more effective than that of other group (p<0.05). But there were no significant differences in the parameters such as the frequency of coitus, premature ejaculation and morning erection between 3 groups (p>0.05). The efficacy achieved with KGR (60%) was significantly higher (p<0.05) than that of placebo (30%) and trazodone (30%). There were no significant changes on level of serum testosterone and type of AVS-penogram in group A. No side effect was demonstrated in all patients.