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Comparisons of Empirical Braking Models for Freight Trains Using P4a Distribution Valve (P4a 분배밸브를 사용하는 화물열차의 경험적 제동모델들의 비교)

  • Choi, Don Bum;Kim, Min-Soo;Lee, Kangmi;Kim, Young-Guk
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.1
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    • pp.61-69
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    • 2020
  • This study examined the braking characteristics of a heavy haul freight train with P4a distribution valves applied to domestic high-speed freight trains. A freight train was composed of 50 cars, which is twice the normal operation. A braking test was performed to confirm the characteristics of the braking of a heavy haul. The brake cylinder pressures were measured for emergency and service braking on the 1st, 10th, 20th, 30th, and 50th cars. Because the brake signal is transmitted to the pressure through the braking tube connected to the end of the train, the rear vehicle is braking later than the vehicle ahead. Therefore, it is necessary to predict the brake pressures in all cars in a train to supplement the results of the limited tests and calculate the braking distance. The pressure in each car was determined using empirical models of linear interpolation, stepwise, and exponential models, which provided reliable information. The predictive results of the empirical models were compared with the measured results, and the exponential model was predicted relatively accurately. These results are expected to contribute to the safe operation of heavy haul freight trains and can be used to predict the braking distance and calculate the level of impact between vehicles during braking.

Factors Influencing Posttraumatic Growth of North Korean Defectors in South Korea (북한이탈주민의 외상 후 성장에 영향을 미치는 요인)

  • Kim, Yun Ah;Kim, MiYoung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.5
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    • pp.332-338
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    • 2016
  • This study examined the posttraumatic growth of North Korean defectors, the relation between their characteristics and posttraumatic growth and the factors influencing their posttraumatic growth, and explored methods of improving their mental health status. 145 North Korean defectors, who were trained in B city and G city, participated in the survey from February 1 to March 10, 2016. The posttraumatic growth, resilience, self-esteem, deliberate rumination, and impact of the (traumatic) event were measured using the PTGI (Posttraumatic Growth Inventory), RS (Rumination Scale, Resilience Scale), SES (Self-esteem Scale) and ISR (Impact of Event). The data were analyzed using the t-test, ANOVA, Pearson correlation coefficient and stepwise multiple regression. The mean scores were 29.64 for posttraumatic growth. There were significant positive correlations between posttraumatic growth and resilience and between posttraumatic growth and rumination. The influence of the independent variables on the total posttraumatic growth was examined using regression analysis. Models including the variables (resilience, positive self-esteem, and rumination) explained 54.2% of the variance for the posttraumatic growth. These findings demonstrate that it is essential for nurses to continuously intervene and help North Korean defectors so as to promote their posttraumatic growth and resilience. Furthermore, it is also necessary for nurses to find ways to develop ideal interventions in order to activate deliberate rumination.

Influence of Nursing Satisfaction, Self-Esteem and Depression on Adjustment of the Elderly in Long-term Care Hospital (요양병원 입원노인의 간호만족도, 자아존중감 및 우울이 적응에 미치는 영향)

  • Lee, Kyoung-Mi;Jo, Eun-Joo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.5
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    • pp.441-451
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    • 2016
  • This study was conducted to determine the influence of satisfaction, self-esteem, and depression on adjustment of elderly patients in long-term care hospitals. The subjects were 116 elderly patients in 15 long-term care hospitals in B and K city. Data were collected from February 14 to March 30, 2015, and analyzed by t-rest, ANOVA, Scheff's test, Pearson correlation coefficients, and stepwise multiple regression. According to the results, there were significant differences in adjustment by religion, marital status, economic status, and perceived level of difficult problems. Adjustment was positively related to satisfaction and self-esteem. In addition, a negative correlation was observed between adjustment and depression. Meaningful variables that influenced the adjustment of elderly patients were depression, satisfaction, self-esteem, and religion. These factors accounted for 53.5% of the total variance in adjustment of the elderly patients in long-term care hospitals, and depression was the most influential factor. In conclusion, development and implementation of effective programs and strategies to reduce depression and to increase satisfaction with care and self-esteem is needed in order to enhance the adjustment of elderly patients in long-term care hospitals.

Analysis of cycle racing ranking using statistical prediction models (통계적 예측모형을 활용한 경륜 경기 순위 분석)

  • Park, Gahee;Park, Rira;Song, Jongwoo
    • The Korean Journal of Applied Statistics
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    • v.30 no.1
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    • pp.25-39
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    • 2017
  • Over 5 million people participate in cycle racing betting and its revenue is more than 2 trillion won. This study predicts the ranking of cycle racing using various statistical analyses and identifies important variables which have influence on ranking. We propose competitive ranking prediction models using various classification and regression methods. Our model can predict rankings with low misclassification rates most of the time. We found that the ranking increases as the grade of a racer decreases and as overall scores increase. Inversely, we can observe that the ranking decreases when the grade of a racer increases, race number four is given, and the ranking of the last race of a racer decreases. We also found that prediction accuracy can be improved when we use centered data per race instead of raw data. However, the real profit from the future data was not high when we applied our prediction model because our model can predict only low-return events well.

Prediction of golf scores on the PGA tour using statistical models (PGA 투어의 골프 스코어 예측 및 분석)

  • Lim, Jungeun;Lim, Youngin;Song, Jongwoo
    • The Korean Journal of Applied Statistics
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    • v.30 no.1
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    • pp.41-55
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    • 2017
  • This study predicts the average scores of top 150 PGA golf players on 132 PGA Tour tournaments (2013-2015) using data mining techniques and statistical analysis. This study also aims to predict the Top 10 and Top 25 best players in 4 different playoffs. Linear and nonlinear regression methods were used to predict average scores. Stepwise regression, all best subset, LASSO, ridge regression and principal component regression were used for the linear regression method. Tree, bagging, gradient boosting, neural network, random forests and KNN were used for nonlinear regression method. We found that the average score increases as fairway firmness or green height or average maximum wind speed increases. We also found that the average score decreases as the number of one-putts or scrambling variable or longest driving distance increases. All 11 different models have low prediction error when predicting the average scores of PGA Tournaments in 2015 which is not included in the training set. However, the performances of Bagging and Random Forest models are the best among all models and these two models have the highest prediction accuracy when predicting the Top 10 and Top 25 best players in 4 different playoffs.

Monitoring Anaerobic Reductive Dechlorination of TCE by Biofilm-Type Culture in Continuous-Flow System (연속흐름반응조에서 바이오필름형태의 탈염소화 미생물에 의한 TCE분해 모니터링)

  • Park, Sunhwa;Han, Kyungjin;Hong, Uijeon;Ahn, Hongil;Kim, Namhee;Kim, Hyunkoo;Kim, Taeseung;Kim, Young
    • Journal of Soil and Groundwater Environment
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    • v.17 no.5
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    • pp.49-55
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    • 2012
  • A 1.28 L-batch reactor and continuous-flow stirred tank reactor (CFSTR) fed with formate and trichloroethene (TCE) were operated for 120 days and 56 days, respectively, to study the effect of formate as electron donor on anaerobic reductive dechlorination (ARD) of TCE to cis-1,2-dichloroethylene (c-DCE), vinyl chloride (VC), and ethylene (ETH). In batch reactor, injected 60 ${\mu}mol$ TCE was completely degraded in the presence of 20% hydrogen gas ($H_2$) in less than 8 days by anaerobic dechlorination mixed-culture (300 mg-soluble protein), Evanite Culture with ability to completely degrade tetrachloroethene (PCE) and -TCE to ETH under anaerobic conditions. Once the formate was used as electron donor instead of hydrogen gas in batch or chemostat system, the TCE-dechlorination rate decreased and acetate production rate increased. It indicates that the concentration of hydrogen produced in both systems is possibly more close to threshold for homoacetogenesis process. Soluble protein concentration of Evanite culture during the batch test increased from 300 mg to 688 mg for 120 days. Through the protein monitoring, we confirmed an increase of microbial population during the reactor operation. In CFSTR test, TCE was fed continuously at 9.9 ppm (75.38 ${\mu}mol/L$) and the influent formate feed concentration increased stepwise from 1.3 mmol/L to 14.3 mmol/L. Injected TCE was accumulated at 18 days of HRT, but TCE was completely degraded at 36 days of HRT without accumulation of the injected-TCE during the left of experiment period, getting $H_2$ from fermentative hydrogen production of injected formate. Although c-DCE was also accumulated for 23 days after beginning of CFSTR operation, it reached steady-state in the presence of excessive formate. We also evaluated microbial dynamic of the culture at different chemical state in the reactor by DGGE (denaturing gradient gel electrophoresis).

The effects of weight-control behaviors, the degree of fatness and dance major on eating disorders (체중조절 특성과 비만도 및 무용전공이 식이장애에 미치는 영향)

  • Kim, No-Eul;Moon, In-Ok
    • The Journal of Korean Society for School & Community Health Education
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    • v.6
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    • pp.49-63
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    • 2005
  • The purpose of this study was to investigate the weight control behaviors, the degree of fatness and dance major on behalf of finding the effects of eating disorders. 779 female high school students, 283 dance major students and 496 general major students, were participated in the study. A self-reporting type of questionnaire survey was conducted during the period from $6^{th}$ May to $18^{th}$ April of 2005. Collected data were processed using SPSSW in 12.0; they were analysed through frequencies, percentages, means and standard deviation, and stepwise multiple regression analysis. The results of this study are as follows : 1. With regard to the level of eating disorders(EAT-26), 33.9% of risk group of eating disorder female dance students, and 13.7% of risk group of eating disorder female general major students. Weight-control behaviors in this research were 1) weight control concerns, 2) weight control trial, 3) weight control methods (prescription of M.D., ways of weight control), 4) eating habits. First, 56.6% of subjects had high concerns about weight control, and 92% of subjects had tried weight control. Second, only 5.1% of subjects were prescribed by M.D. Third, subjects had been using wrong methods(25.7%) of weigh control such as fasting, using drugs, vomiting, wearing laps etc. Fourth, 42.7% of the subjects had bad eating habits. The degree of fatness was as follows: 1) BMI(Body Mass Index), 2) self report about weight 3) distorted body image. Depending upon the BMI, the subjects with obesity were not found in female dance students; Comparatively, 36.9% of dance students were fat and 1.4% of the students were very fat. In terms of distorted body image, only 14.9% of all subjects were the same between the subjective degree of fatness and the objective degree of fatness. 2. As a result of multiple regression, six variables were found significant($R^2=11.6%$, P < 0.01). Concerns about the weight control significantly influenced on eating disorders(EAT-26). At the same time, major(dance), wrong methods of weight control, distorted body image, prescription of M.D, and eating habits had significantly influenced on eating disorders. This results indicates that the risk of eating disorders among female dancer students was very high. Therefore, professional intervention is needed for female dance students to prevent the eating disorders.

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Effect of Daily Protein Allowances during Lay on Egg Production and Feed Cost of Broiler Breeders (육용종계 산란기의 단백질 공급수준이 산란능력과 경제성에 미치는 영향)

  • 함영훈;김상인;이규호
    • Korean Journal of Poultry Science
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    • v.30 no.2
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    • pp.101-106
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    • 2003
  • In order to study the optimum daily protein allowance for broiler breeders of 24 to 64 weeks of age on a control-fed basis, an experiment was carried out with 400 hens of Arbor Acres strain. Four levels of protein allowances were used to supply 18 to 24g of protein per day in 2g increments. As the age of hens increased, a same stepwise increase and decrease in daily energy allotment was used in all treatments. Same amount of calcium, phosphorus, methionine and lysine were supplied in all treatments and throughout laying period. Hen-day egg production was highest in hens receiving 20g protein per day(p<0.05), but there was no significant difference among those fed daily protein ranging 18 to 22g, and increasing the daily protein allotment up to 24g resulted in a significant decrease(p<0.05). Average egg weight showed a trend to increase as the daily protein allowance increase(p<0.05), but no significant difference was found among the hens fed daily protein 20 to 24g. Feed and ME conversion was superior in hens receiving 20g daily protein(p<0.05). CP conversion was increased as the daily protein allowance increase(p<0.05), but there was no significant difference between hens receiving 18 and 20g daily protein. Feed cost required per egg or per kg egg was lowest in hens fed 20g daily protein. It could be concluded that the optimum daily protein allowance was 20g in all performances.

The Effects of a Functional Movement Screen on Pain and Performance Ability in Professional Fencing Players (펜싱선수에서 통증과 수행 능력이 기능적 동작 검사에 미치는 영향)

  • Kim, Seong-Yeol;Lee, Je-Hoon;An, Seung-Heon
    • The Journal of Korean Physical Therapy
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    • v.23 no.1
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    • pp.21-28
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    • 2011
  • Purpose: The aim of this study was to investigate correlations between the Functional Movement Screen (FMS), pain, and performance ability in professional fencing players. Methods: Fifty-six athletes participated in this study. The pain group included those who had a score on a pain-related Visual Analogue Scale (VAS) of ${\geq}$20 and an Oswestry Disability Index (ODI) score ${\geq}$10). In the non-pain group, these scores were: VAS(<20), ODI(<10). The VAS and ODI were used to measure pain throughout the study. Performance ability included motor function of the lower extremities (as assessed by a Modified Functional Index Questionnaire, MFIQ), dynamic balance (Balance system, BS and Posture med, PM), flexor and extensor muscle strength of the lumbar region was recorded as maximal isometric strength. Results: Among athletes who had pain, 5 of 15(33.33%) showed impaired functional movement. Conversely, only 2 of 41(4.88%) of those who had no pain showed such impairment (FMS ${\leq}$14score). The athletes who had pain and who had an FMS score above 14 (10/56; 17.86%) showed a significantly higher score for extensor muscle strength of the lumbar compared with those with pain and an FMS score below 14 (5/56; 8.93%) were significant correlations between the FMS and pain (r=-0.40 to -0.42, p<0.01), the MFIQ (r=-0.33, p<0.05), dynamic balance (r=-0.27 to -0.40, p<0.05-0.01), muscle strength of the lumbar (r=0.27 to 0.29, p<0.05). Stepwise multiple regression analysis showed that the dynamic balance score (${\beta}{\beta}$=-0.41) had slightly more power in predicting FMS score than pain, motor function of lower extremity, or muscle strength. Conclusion: The FMS was significantly associated with values of pain, motor function of the lower extremities, dynamic balance, and muscle strength of the lumbar. However the FMS appears to lack relevance and reasonable evidence to suggest that it is an acceptable measurement tool for functional movement analysis.

Adaptation of Feedlot Cattle to a High-energy Ration by Intraruminal Transplantation of Adapted Ruminal Fluid (제1위내용액 이식에 의한 비육우의 농후사료 적응법에 관한 연구)

  • 이현범;탁연빈;성은주;김기석;이영주;정재석;장종식;권오덕
    • Journal of Veterinary Clinics
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    • v.15 no.1
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    • pp.62-74
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    • 1998
  • In feedlot cattle the abrupt change of diet from roughage to a large quantity of grain for the purpose to improve production often results in increased occurrence of rumen acidosis or acute carbohydrate encouragement enterotoxemia, bloats diarrhea liver abscess and laminitis or robot disease. The common management practice to control these problem is to increase the amount of concentrates in the diet in a stepwise manner until the animals are adapted to a high-grain ration. However this practice requires at least about 3 weeks adaptation period and specially prepared adaptation rations which contain various amount of concentrates. Present experiment was undertaken in order to findout the more simple and rapid adaptation method of cattle to a high grain ration. Nineteen Korean calves aging from four to six month were fed artifical hay (Youngchoun Chuk-Hyup, Korea) which contains 10% of concentrates or alfalfa and rye grass hays for two months and randomly alloted to three experimental groups and two control groups. The experimental group-1 was inoculated by stomach tube for two days with li500 ml/day of ruminal fluid fished from Korean beef cattle that had been previously adapted to a high-energy ration. The experimental group-2 was inoculated by trocalization for two days with the same ruminal fluid. The experimental group-3 was inoculated by trocalization with 1,500 ml/day of bacterial culture which contained 2$\times $10$^{9}$/m1 of Gram-negative bacteria derived from adapted luminal fluid. The two control groups were treated with normal saline solution by the same methods. All animals were fed high-energy ration that contained 80% of grain ad libitum for 30-74 days beginning on the third of the treatment. The effect of the inoculation on the adaptation was observed clinicopathologically with the following results; All of the experimental calves inoculated with the ruminal fluid or Gram-negative bacterial culture derived from adapted cattle did not show any signs of rumen acidosis or other related diseases, while most of the control calves did show diarrhea and bloat and a calf laminitis. The average daily weight gain and feed efficiency of experimental calves were slightly improved compared with control calves. Following the feeding of high-grain rational the pH of the ruminal fluid was lowered in both the experimental and control groups. However severe acidosis with the pH of below 5.0 was observed in only a control group-2. The protozoal number in ruminal fluid was markedly decreased during the high-grain feeding in both the experimental and control calves. However the decrease was mere severe in control calves compared with the experimental calves. The activation of the protozoa were completely disappeared within nine hours at the refrigerator temperature (4"C). No significant differences in heamatological and blood chemical values between the experimental and control calves were recognized. However in one control calf which showed clinically laminitis marked elevations of serum glutamic oxaloacetate transaminase and lactic dehydrogenase activities and a decrease of serum glucose level were observed. From these results it would be concluded the intraruminal transplantation of unadapted calves with the adapted ruminal fluid from cattle previously adapted to a high-energy ration prevents disease problem associated with high-grain feeding and improve weight gain and feed efficiency.ency.

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