• 한국환경과학회지
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• 제1권2호
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• pp.49-57
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• 1992

First, We classified man-made lakes in Korea as 4-type lakes, that is, there were River-run lakes, Dendritic lakes, Reservoir-lakes, River-mouth lakes, We studied on the environmental factors of 3-type lakes except River-mouth lakes, compared these lakes with natural lakes in foreign country. Environmental factors were watershed area, lake storage, mean depth, hydraulic retention time. As a results, 3-type lakes in Korea had remarkable differences one another according to above-mentioned environmental factors. First, We recognized that River-run lakes had higher nutrient loading according to having wider watershed area than natural lakes, and had lower algal growth rate according to shorter hydraulic retention time than natural lakes. Dendritic lake had higher nutrient loading than natural lakes, longer retention time than River-run lake. Reservoir-lakes had environmental factors between Dentritic lakes and River-run lakes. Therefore, If this studies had no quantitative results about various factors, We recognized that man-made lakes in korea had different environmental factors as compared with natural lakes, and had clear classification among 3-type lakes.

• Biotechnology and Bioprocess Engineering:BBE
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• 제6권1호
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• pp.37-41
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• 2001

HPLC separation of ionic samples tends to be more complicated and difficult to understand than that of non-ionic compounds. On the other hand, band spacing is much more easily manipulated for ionic than for neutral samples. Ion-suppression RP-HPLC method was used with organic modifier and aqueous buffer solution. In this work, five mononucleotides of cytidine-5-monophosphate (5-CMP) disodium salt, uridine-5-monophosphate disodium salt (5-UMP), guanosine-5-monophosphate disodium salt (5-GMP), inosine-5-monophosphate disodium salt (5-IMP), and adenosine-5-monophosphate disodium salt (5-AMP) were examined. Acetic acid and sodium phosphate were used as buffers, and methanol as an organic modifier. A new relationship between the retention factor and the buffer concentration at a fixed modifier content (5% of methanol) could be expressed by following: K = (k(sub)-1 + k(sub)0 (k(sub)B/k(sub)S)/(1 + (k(sub)B/k(sub)S) C(sub)B(sup)a), where C(sub)B was the concentration of buffer. Using this relationship, the calculated values closely matched the experimental data. The derived relationship showed that as the buffer concentration increased, the retention factor approached a certain value, and this was buffer dependent.

• 한국생활과학회지
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• 제21권6호
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• pp.1173-1184
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• 2012

This study estimates a structural model to examine the causal relationships among web browsing, switching cost, and site retention in the context of apparel shopping website. A total of 499 usable questionnaires were obtained from consumers aged from 20 to 49 years. For data analysis, exploratory factor analysis, confirmatory factor analysis and structural model were used. The result showed that consumer's perceived switching costs consisted of three factors: relationship cost, search cost and benefit loss cost. In estimated structural model, the relationship cost was influenced by leisure browsing; the search cost was influenced by informational browsing and leisure browsing; the benefit loss cost was influenced by leisure browsing. Especially, the leisure browsing was the most highly related to the benefit loss cost, and followed by relationship cost and search cost. However, hedonic browsing was not significantly related the factors of switching costs. The search costs significantly affected customer's intentions for site retention. A managerial implication was discussed for e-retailers in order to develop strategic switching costs in building long-term relationships with web browsers on the apparel shopping websites.

• Asian-Australasian Journal of Animal Sciences
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• 제24권10호
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• pp.1393-1398
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• 2011

Four 4-month old Charolais${\times}$Dorset male sheep (initial liveweight $25.0{\pm}1.1\;kg$), fitted with rumen and abomasal fistulas and nourished by total intragastric infusions, were used to study the relationships between methionine (Met) supply, nitrogen (N) retention and plasma insulin-like growth factor-I (IGF-I). Four graded levels of Met, i.e. 0 g/16 g N, 1.76 g/16 g N, 3.52 g/16 g N and 7.04 g/16 g N, were infused into abomasums as experimental treatments. The sheep and treatments were allocated in a $4{\times}3$ incomplete Latin square design (Yudon square design). The experiment lasted 3 periods and each period was 10 days. Quadratic correlations were found between Met level (x, g/16 g N) and N retention (y, g/d): y = $-0.03x^2$+0.41x+2.62, $r^2$ = 0.66, n = 12, p = 0.008, and between methionine level (x, g/16 g N) and plasma IGF-I concentration (y, ng/ml): y = $0.80x^2$-4.53x+190.24, $r^2$ = 0.51, n = 12, p = 0.009. No significant correlation was found between plasma IGF-I (x, ng/ml) and N retention (y, g/d) (p>0.05). It was concluded that Met level had a significant influence on N retention and plasma IGF-I concentration whereas IGF-I might not be an important mediator in the regulation of N metabolism by Met in growing sheep nourished by total intragastric infusions.

• 한국치위생학회지
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• 제20권4호
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• pp.505-514
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• 2020

Objectives: Although dental hygienists are professional workers, their job retention is short. Therefore, in order to improve job retention, the relationship between professional identity and professional self-concept was analyzed. Methods: From January 1 to April 30, 2020, 155 dental hygienists were examined. For data analysis, multiple regression analysis was conducted to confirm the effects of professional identity and professional self-concept on job retention. Results: The dental hygienist's professional self-concept was significantly higher in the team manager than in the staff, but the professional identity was not significantly different. Dental hygienists' professional identity, professional self-concept, and job retention were all positively correlated (p<0.05). As a factor influencing dental hygienist's job retention, the self-concept of the profession had a significant effect, but the identity of the profession did not. Conclusions: Since the professional self-concept has a positive effect on maintaining the profession of dental hygienists, it is necessary to make efforts to improve the professional self-concept in order to increase the job retention.

• 임상간호연구
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• 제27권1호
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• pp.23-34
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• 2021

Purpose: The purpose of this study is to examine the mediating effect of professional quality of life among hospital nurses in the effects of workplace bullying, social support and resilience on retention intention. Methods: A descriptive and cross-sectional study was conducted on 414 hospital nurses who worked for at least two months at a general hospital in the Seoul metropolitan area. The data were analyzed using IBM SPSS 23.0/AMOS 22.0 programs and employed reliability verification, descriptive statistics include frequency analysis, confirmatory factor analysis, structural equation modeling, and bootstrapping. Results: As a result of the study's structural modeling verification, workplace bullying had a negative effect, social support had a positive effect, resilience had a positive effect on professional quality of life, and professional quality of life had a positive effect on retention intention. Also, workplace bullying, social support, and resilience did not directly impact on retention intention. However, the professional quality of life had a complete mediating effect in the relationships between workplace bullying, social support, resilience and retention intention. The study results verified the mediating effect of professional quality of life affecting the retention intention. Conclusion: In order to improve professional quality of life and retention intention, strategies to prevent workplace bullying and promote social support and resilience are needed.

• Asian-Australasian Journal of Animal Sciences
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• 제20권6호
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• pp.989-993
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• 2007

A lactose-hydrolyzed milk with low sweetness was developed using nanofiltration. Raw milk was treated with 0.03% ${\beta}$-galactosidase at $4^{\circ}C$ for 24 h to hydrolyze lactose partially. The resultant lactose-hydrolyzed milk containing 0.43% lactose was then concentrated using a nanofiltration membrane to reach concentration factor of 2.13. The concentration factors and coefficients of retention of milk components in nanofiltration were determined. The concentration factor of milk fat was 2.20 which was the highest of the milk components. The coefficient of retention of calcium and riboflavin was 0.96 and 0.76, respectively. However, the coefficient of retention of glucose, galactose, and sodium was 0.21, 0.15, and 0.22, respectively. Raw milk was treated with 0.1% ${\beta}$-galactosidase at $4^{\circ}C$ for 40 h to hydrolyze lactose fully and then concentrated to reach a concentration factor of 1.6 by using nanofiltration. The concentrated milk was reconstituted with water. The lactose-hydrolyzed milk had sweetness similar to milk. The compositional ratios of crude protein, calcium, sodium, and riboflavin of lactose-hydrolyzed nanofiltrated milk to those of raw milk were 99%, 97%, 77%, and 80%, respectively. This study showed that nanofiltration of lactose-hydrolyzed milk to remove galactose and glucose did not cause significant loss of calcium. The lactose-hydrolyzed nanofiltrated milk contained 0.06% lactose and had sweetness similar to milk.

• 대한공업교육학회지
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• 제40권1호
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• pp.87-104
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• 2015

이 연구는 발명교사교육센터에서 추진하고 있는 현직교사 대상의 발명교육 직무연수의 현업적용도를 확인하기 위해서 수행되었다. 연구의 목적을 달성하기 위해서 연수 이수 1년 후 시점에서 이수자가 인식하는 학습 파지도, 연수 유용도, 연수 내용의 교육 활용도, 발명교육 능력 향상도를 알아보았다. 이 연구는 2013년 동남권 발명교사교육센터의 직무연수를 이수한 현직교원 60명을 대상으로 하였으며, 현업적용도 조사 연구와 연수 후기에 대한 질적 분석으로 수행되었다. 연수 이수자 60명 중 현업적용도 조사에 응답한 인원은 30명, 연수 후기 작성에 참여한 인원은 12명이다. 동남권 발명교사교육센터에서 2013년에 추진한 현직교원 대상의 직무연수 현업적 용도의 평균값은 5점 만점에 4.07점으로 비교적 높은 점수로 확인되었다. 연수 이수 1년 후 이수자가 인식하는 현업적용도의 하위 항목은 교육능력 향상도 4.39점, 연수 유용도 4.11점, 교육 활용도 3.94점, 학습 파지도 3.82점의 순이다. 현업적용도의 전체 평균 4.07점을 기준으로 보았을 때, 교육능력 향상도와 연수 유용도는 상대적으로 높은 값을 보였고, 교육 활용도와 학습 파지도는 상대적으로 낮은 값으로 확인되었다. 연수 이수자의 현업적용도에 대한 질적 분석 자료로 확보한 12편의 연수 후기에 대한 내용을 분석한 결과, 학습 파지도, 연수 유용도, 교육 활용도, 교육 능력 향상도를 직 간접적으로 설명할 수 있는 의미 있는 사례를 도출하였다.

• Journal of Gastric Cancer
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• 제21권3호
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• pp.298-307
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• 2021

Purpose: Delayed gastric emptying usually manifests as gastric food retention. This study aimed to evaluate the incidence of gastric food retention after distal gastrectomy with gastrojejunostomy in gastric cancer patients and identify the risk factors for its development. Materials and Methods: We retrospectively enrolled 245 patients who underwent distal gastrectomy with gastrojejunostomy for gastric cancer at Boramae Medical Center between March 2017 and December 2019. We analyzed the presence of gastric food residue via computed tomography (CT) scans at 3 and 12 months postoperatively and analyzed the risk factors that may influence the development of gastric food retention. Results: CT scans were performed on 235 patients at 3 months and on 217 patients at 12 months postoperatively. In the group that received closure of Petersen's space, the incidence of gastric food retention was significantly low as per the 3- and 12-month postoperative follow-up CT scans (P=0.028 and 0.003, respectively). In addition, hypertension was related to gastric food retention as per the 12-month postoperative follow-up CT scans (P=0.011). No other factors were related to the development of gastric food retention. In the multivariate analysis, non-closure of Petersen's space (hazard ratio [HR], 2.54; 95% confidence interval [CI], 1.20-5.38; P=0.010) was the only significant risk factor for gastric food retention at 3 months postoperatively, while non-closure of Petersen's space (HR, 2.81; 95% CI, 1.40-5.64; P=0.004) and hypertension (HR, 2.30; 95% CI, 1.14-4.63; P=0.020) were both significant risk factors for gastric food retention at 12 months postoperatively. Conclusions: Closure of Petersen's space has an effect on decrease the incidence of gastric food retention after distal gastrectomy with gastrojejunostomy in gastric cancer patients.

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제21권2호
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• pp.331-345
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• 2007

본 연구에서는 중학생들이 수학 평가 결과를 어떻게 파지하는지를 탐구하고자 하였다. 이를 위해, 측정시기, 문항 유형, 성적, 평가요소 등을 학생들이 평가결과를 파지하는데 중요한 요인이라고 보고 이 변인들과 관련된 학생들의 평가결과 파지 유형을 분류하였다. 이를 토대로, 두 명의 연구 참여자를 선정하여 심층면담을 진행함으로써 그들의 평가에서 핵심적인 역할을 하는 요소가 무엇이며 그것이 향후에 어떤 형태로 파지되어 나타나는지를 분석함으로써 중학생들의 수학과 평가 결과의 파지 유형을 분석하였다.