• Title/Summary/Keyword: Design comparison

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An analytical study on the thermal performance of multi-tube CO2 water heater (다중관형 CO2 급탕열교환기의 열적성능에 대한 해석연구)

  • Chang, Keun Sun;Choi, Youn Sung;Kim, Young-Jae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.8
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    • pp.23-30
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    • 2016
  • In this study, the heat transfer and pressure drop characteristics were evaluated for multi-tube $CO_2$ water heaters with lengths of 4.5 m and 7.5 m. The evaluation was done using the -NTU method, and the results were compared with experimental data. Water flows through the shell side of the water heater, while $CO_2$ flows through 8 inner tubes. The heater uses a counter-current design to maximize the heat transfer efficiency. The energy balance equation describing the flows of $CO_2$ and water for each node is set up using the section-by-section method. The calculated heat transfer rates agree well with the experimental data within ${\pm}5%$ error. The outlet water temperature decreased linearly with the increase of the water flow rate. The calculated heat transfer rates agreed well with the experimental data within ${\pm}3%$ error. The results show that the heat transfer rate increases almost linearly with the increase of water flow rate or $CO_2$ inlet temperature in both the 4.5-m and 7.5-m water heaters, whereas the water outlet temperature linearly decreases with the increase of the water flow rate. The comparison of the $CO_2$ pressure drop between the calculation and experiment results shows good agreement at the high $CO_2$ flow rate within 5 % error, but the value is about 20 % higher in the experimental pressure drop at the low $CO_2$ flow rate.

Effect of Nursing Case-Focused Creative Thinking Training for Registered Nurses (간호사의 간호사례 중심 창의적 사고훈련 효과)

  • Kang, So-Young;Kim, Hyun-Ju
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.6
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    • pp.2898-2907
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    • 2013
  • The purpose of this study was to develop the creative thinking training program(CTTP) focused on a nursing case for registered nurses(RN) working at hospital, and to examine the CTTP's effects on nurses' creative thinking ability and disposition. This quasi-experimental study was conducted on the basis of pre and post-test design with a comparison group for nurses enrolled in registered nurse bachelor science degree program in a University located in Southern area of Korea. The 5 hour-CTTP, including 7 creative activity tasks related to a nursing case, was implemented on 35 RNs of the experimental group from November 21, throughout November 28, 2011. The 39 RNs were participated in this study as a control group. Pre-and post-tests were done with the questionnaire items of the Integrated Creativity Instrument for creative ability and creative disposition. There were significant differences in creative thinking ability(t=3.62, p=001) and creative disposition(t=2.91, p=.01) between the experimental and the control group. The CTTP, developed in this research would contribute to increasing creativity competency for registered nurses.

Pull-out Capacity of Cast-in-place Anchor for Construction of Precast Concrete Segment Arch (프리캐스트 콘크리트 패널 분절 아치 시공을 위한 선설치 앵커의 인발 강도 평가)

  • Ahn, Jin-Hee;Yim, Hong Jae;Bang, Jin Soo;Jeon, Seok Hyeon
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.24 no.2
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    • pp.94-102
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    • 2020
  • Precast concrete segment arch system has an economic and construct ability that combined with advantage of precast concrete and arch behavior. A precast concrete segment arch system with outrigger is consisted of segmented precast panels, a steel outrigger rib, and V-strip to connect precast panels with a steel outrigger rib and cast-in-place anchors in precast panels to connect V-strip should have sufficient pull-out capacity to form its arch shape by site lifting for assembled precast panels and outriggers. However, it is difficult to secure its embedment depth due to the relatively shallow thickness of precast panel. It can be also occurred that flexure deformation of precast panels caused by its pull-out behaviors. In this study, pull-out capacity of cast-in-place anchor was examined for construction of precast concrete segment arch system with outriggers. Therefore, a total of 24 precast panel specimens were fabricated to examine pull-out capacities of cast-in-place anchor in precast panels, and installation depth of anchors, diameter of anchors and wire mesh effects for the precast panel were examined. From this pull-out tests, its pull-out capacities and failure modes were evaluated and the type of the cast-in-place anchor applicable to the precast concrete segment panel arch system with outriggers was determined from comparison of the design specification values.

A Clinical Trial to Assess the Efficacy of Acupuncture on Hot Flashes in Postmenopausal Women;Focusing on the comparison of the effects of Traditional Korean medical acupuncture (TKMA) and Minimal Acupuncture (MA)

  • Kim, Dong-Il;Roh, Jin-Ju;Choi, Min-Sun;Lee, Seung-Deok;Roh, Ju-Won;Yoon, Sang-Ho;Ahn, Hong-Yup;Oh, Dal-Seok;Choi, Sun-Mi
    • The Journal of Korean Medicine
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    • v.28 no.4
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    • pp.74-85
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    • 2007
  • Objective : In this study we wanted to confirm if proper stimulation and de-Qi of traditional Korean medical acupuncture could increase hot flash relief efficacy. Design : A randomized controlled, single blind study. We used two modalities of acupuncture, one with optimal stimulation [Study group; Korean medical acupuncture (TKMA)] and one with minimal stimulation [Control group; Minimal acupuncture (MA)]. Same acupoints [PC6(內關), HT8(少府), HT7(神門), LI4(合谷), ST36(足三里), SP6(三陰交), Ren4(關元)] were used in both groups. Fifty-two patients were treated twice a week for 8 weeks, and follow up was done after 4 weeks from the last treatment. Patients were checked hot flash VAS (visual analog scale), frequency and duration every time they visited. Results : Hot flash relief efficacy by 100mm hot flash VAS was obvious in both groups. Hot flash VAS scores of study group were smaller than the scores of control group at the early stage (3rd, $4^{th}$ and $8^{th}$ visit), but there wasn't a remarkable difference between study and control group at the end of the trial. Besides, diminution of hot flash VAS was faster and more even in the study group than control group by visualization using 'Box plot'. We compared frequency and duration of hot flash, 100mm sweating, palpitation, sleep disturbance VAS, and Kupperman Index, MENQOL, Patient's global assessment score. Both groups showed definite decrease from the baseline, but the difference was not statistically significant. There wasn't any adverse event. Hot flash relief efficacy was kept in most patients after 4 weeks' follow-up. Conclusion : Acupoint combination by Traditional Korean medical theory is effective on hot flashes and hot flash relief efficacy was faster and more even in optimal stimulation than minimal stimulation.

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Electricity Consumption as an Indicator of Real Economic Status (전력소비를 이용한 실물경기지수 개발에 관한 연구)

  • Oh, Seung-Hwan;Kim, Tea-Joong;Kwak, Dong-Chul
    • Journal of Distribution Science
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    • v.14 no.3
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    • pp.63-71
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    • 2016
  • Purpose - A variety of indicators are used for the diagnosis of economic situation. However, most indicators explain the past economic situation because of the time difference between the measurement and announcement. This study aims to argue for the resurrection of an idea: electricity demand can be used as an indicator of economic activity. In addition, this study made an endeavor to develop a new Real Business Index(RBI) which could quickly represent the real economic condition based on the sales statistics of industrial and public electricity. Research design, data, and methodology - In this study monthly sales of industrial and public electricity from 2000 to 2015 was investigated to analyze the relationship between the economic condition and the amount of electricity consumption and to develop a new Real Business Index. To formulate the Index, this study followed next three steps. First, we decided the explanatory variables, period, and collected data. Second, after calculating the monthly changes for each variable, standardization and estimating the weighted value were conducted. Third, the computation of RBI finalized the development of empirical model. The principal component analysis was used to evaluate the weighted contribution ratio among 3 sectors and 17 data. Hodrick-Prescott filter analysis was used to verify the robustness of out model. Results - The empirical results are as follows. First, compatibility of the predictability between the new RBI and the existing monthly cycle of coincident composite index was extremely high. Second, two indexes had a high correlation of 0.7156. In addition, Hodrick-Prescott filter analysis demonstrated that two indexed also had accompany relationship. Third, when the changes of two indexes were compared, they were found that the times when the highest and the lowest point happened were similar, which suggested that it is possible to use the new RBI index as a complementing indicator in a sense that the RBI can explain the economic condition almost in real time. Conclusion - A new economic index which can explain the economic condition needs to be developed well and rapidly in a sense that it is useful to determine accurately the current economic condition to establish economic policy and corporate strategy. The salse of electricity has a close relationship with economic conditions because electricity is utilized as a main resource of industrial production. Furthermore, the result of the sales of electricity can be gathered almost in real time. This study applied the econometrics model to the statistics of the sales of industrial and public electricity. In conclusion, the new RBI index was highly related with the existing monthly economic indexes. In addition, the comparison between the RBI index and other indexes demonstrated that the direction of the economic change and the times when the highest and lowest points had happened were almost the same. Therefore, this RBI index can become the supplementary indicator of the official indicators published by Korean Bank or the statistics Korea.

Overseas Expansion Support to Small and Medium Enterprises: The Case of Japan and Germany (중소기업 해외진출지원에 관한 연구: 일본과 독일의 지원정책사례를 중심으로)

  • Koji, Yoshimoto;Bae, Il-Hyun
    • Journal of Distribution Science
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    • v.13 no.7
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    • pp.53-61
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    • 2015
  • Purpose - This research analyzes overseas expansion support systems for small- and medium-sized enterprises in Germany and Japan. Germany and Japan have developed overseas expansion support policies for such enterprises. The study then explores the implications for Korea and its local governments. Research design, data, and methodology - We did a comparative analysis of Japan and Germany and their support for overseas expansion of small and medium companies. Data were mainly collected from the Ministry of Economy, Trade and Industry (Japan) and the Germany Trade and Invest (Germany) agency through statistics and literature surveys, and analysis studies. Results - First, human resources cultivation and funding support policies, which both Germany and Japan use as part of small- and medium-sized enterprise policies, should be modified to Korean circumstances and to reflect its own small- and medium-sized enterprise support needs. Second, both the German policies that support overseas expansion of small- and medium-sized enterprises and those of Japan's include the philosophy and methods that put an emphasis on these enterprises, despite the fact that there are big differences in the overseas policies in these two countries. Third, German and Japanese governments are embracing the idea that small- and medium-sized enterprises are key to their national economies and implementing policies based on the ratio occupied by these enterprises in the domestic consumption or GDP. In other words, Germany and Japan consider small- and medium-sized enterprises as central to their nation's industry, and assess them as economic industry that should definitely exist for the continued survival of big businesses, and not just as merely supplemental to big business. Fourth, whereas Germany emphasizes support to product exhibition in its overseas expansion support policies, Japan is providing integrated support containing foreign direct investment to small- and medium-sized enterprises. Fifth, there are differences in the overseas expansion support in Germany and Japan in terms of their support to big business. Whereas Germany considers support to big business unnecessary, Japan is implementing active support policies to areas corresponding to big business. Korea will have to benchmark the policies of Germany and Japan, and decide whether or not to give full support to small- and medium-sized enterprises, while excluding areas supporting big business. Conclusions - Based on this analysis of German and Japanese overseas expansion support policies, we need to choose the policies that will engender a solid outcome and derive modified policies for the circumstances of Korea. Additionally, we can use the comparison of the overseas support policies of Japan and Germany to choose small- and medium-sized enterprise overseas expansion support policies for Korea. However, we cannot provide specific overseas support policies by industry. This point will be referenced as a limitation of this study. In future research, we expect that some researchers will take an empirical approach to exploring Korean overseas expansion support through collecting cases of overseas support policies and interviewing policy authorities.

Effects of Executive Compassion and Forgiving Behavior on Organizational Activities and Performance (중소기업에서 경영자의 배려와 용서가 학습조직 활동과 조직성과에 미치는 영향)

  • Park, Soo-Yong;Hawang, Moon-Young;Chol, Eun-Soo
    • Journal of Distribution Science
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    • v.13 no.6
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    • pp.105-118
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    • 2015
  • Purpose - Currently, strengthening small and medium-sized enterprises (SME) in terms of competitiveness is a key economic issue. However, the problem is that many SMEs lack the internal competence required to cope with a rapidly changing market structure. Such problems can act as an obstacle to economic development, yet most SMEs in Korea are dealing with this problem today. A company's source of competitive advantage is changing from quantity to quality, facility to knowledge, and hardwork to creativity. Under such circumstances, a company should place learning and sharing of knowledge and continuously creating new knowledge as its priority. This study aims to identify the effect of a chief executive officer's (CEO) compassion and forgiveness - positive factors in organizational emotion - on learning organization activities and organizational performance, through a theoretical comparison. Research design, data, and methodology - For this study, SMEs based in Daejeon and Chungcheong area were selected. To secure credibility of the data, the subjects were selected among those who have been working at the business for six months or longer. The survey was conducted for 30 days from March 5, 2015 to April 5, 2015. Both offline and online surveys were conducted. Fifty companies were chosen and 700 questionnaires were distributed, with 506 used for analysis. Fifty subject companies (25 from Daejeon, 10 from Chungnam, 10 from Chungbuk, and five from Sejong) were selected and the objective, target, and survey content were explained to a manager at each company either face-to-face or on the phone. Of the total of 700 questionnaires distributed via mail or e-mail, 78.6% or 550 copies were returned. Excluding 44 insufficient questionnaires, the remainder, 506 questionnaires, were used for analysis. Results - This study analyzed how the CEO's compassion and forgiveness affects learning organization activities and organizational performance. First, compassion of the CEO at the SMEs directly affected the learning organization activities and indirectly affected the organizational performance. Second, forgiveness of the CEO at the SMEs did not affect the learning organization activities and organizational performance directly or indirectly. Conclusions - The study conclusions are as follows. First, CEO compassionate behavior at the SMEs was a significant variable that directly and indirectly affected learning organization activities and organizational performance. Therefore, the CEO of an SME can create a positive organizational atmosphere through compassionate behaviors in the organization. Second, the forgiving behavior of the CEO did not have direct or indirect effects on learning organization activities and organizational performance. However, the reason for a CEO to continue his or her forgiving behavior is because it strengthens employee resilience, commitment, and self-efficacy to protect the organization from negative influences such as layoffs, risks, and wrongdoings. The action of forgiveness does not have direct or indirect effects. However, the CEO shall continue such behavior to strengthen members' physiological resilience, commitment, and self - effectiveness, and to protect the organization from risks including layoff and external negative factors.

A Study on the Impact of Oil Price Volatility on Korean Macro Economic Activities : An EGARCH and VECM Approach (국제유가의 변동성이 한국 거시경제에 미치는 영향 분석 : EGARCH 및 VECM 모형의 응용)

  • Kim, Sang-Su
    • Journal of Distribution Science
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    • v.11 no.10
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    • pp.73-79
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    • 2013
  • Purpose - This study examines the impact of oil price volatility on economic activities in Korea. The new millennium has seen a deregulation in the crude oil market, which invited immense capital inflow into Korea. It has also raised oil price levels and volatility. Drawing on the recent theoretical literature that emphasizes the role of volatility, this paper attends to the asymmetric changes in economic growth in response to the oil price movement. This study further examines several key macroeconomic variables, such as interest rate, production, and inflation. We come to the conclusion that oil price volatility can, in some part, explain the structural changes. Research design, data, and methodology - We use two methodological frameworks in this study. First, in regards to the oil price uncertainty, we use an Exponential-GARCH (Exponential Generalized Autoregressive Conditional Heteroskedasticity: EGARCH) model estimate to elucidate the asymmetric effect of oil price shock on the conditional oil price volatility. Second, along with the estimation of the conditional volatility by the EGARCH model, we use the estimates in a VECM (Vector Error Correction Model). The study thus examines the dynamic impacts of oil price volatility on industrial production, price levels, and monetary policy responses. We also approximate the monetary policy function by the yield of monetary stabilization bond. The data collected for the study ranges from 1990: M1 to 2013: M7. In the VECM analysis section, the time span is split into two sub-periods; one from 1990 to 1999, and another from 2000 to 2013, due to the U.S. CFTC (Commodity Futures Trading Commission) deregulation on the crude oil futures that became effective in 2000. This paper intends to probe the relationship between oil price uncertainty and macroeconomic variables since the structural change in the oil market became effective. Results and Conclusions - The dynamic impulse response functions obtained from the VECM show a prolonged dampening effect of oil price volatility shock on the industrial production across all sub-periods. We also find that inflation measured by CPI rises by one standard deviation shock in response to oil price uncertainty, and lasts for the ensuing period. In addition, the impulse response functions allude that South Korea practices an expansionary monetary policy in response to oil price shocks, which stems from oil price uncertainty. Moreover, a comparison of the results of the dynamic impulse response functions from the two sub-periods suggests that the dynamic relationships have strengthened since 2000. Specifically, the results are most drastic in terms of industrial production; the impact of oil price volatility shocks has more than doubled from the year 2000 onwards. These results again indicate that the relationships between crude oil price uncertainty and Korean macroeconomic activities have been strengthened since the year2000, which resulted in a structural change in the crude oil market due to the deregulation of the crude oil futures.

The effect of Camelina sativa (L.) cv. Crantz Seed Yield according to Seeding Rate and Chemical Fertilization (파종량과 비료 시용이 봄 재배용 카멜리나 종자 생산량에 미치는 영향)

  • Park, Min-Woo;Choi, Chung-Won;Wu, Ming-Gen;Lee, Sang-Hyeob
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.60 no.1
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    • pp.85-90
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    • 2015
  • The objective of this study was comparison of seed yields according to different seeding rates, seeding time and application of chemical fertilizations in Yanji region of China. The experiment was conducted on commercial farmland at Yanji region in 2013. All the experimental fields were designed following randomized block design with 3 replicates. The plant spacing was applied as $65{\times}1cm$ distance. To check the effect of seeding rate, two different seeding rate, 0.2 kg/0.1ha and 0.5 kg/0.1ha were applied. The higher seed yield was observed in low seeding rate (0.2 kg/0.1ha). The application of fertilizer (mixture of N and P) showed different results following different experimental fields. However, there were little positive effects following fertilizer application into commercial farmland. When we compare seed yields between two different seeding dates, $4^{th}$ May and $29^{th}$ May, the earlier seeding date ($4^{th}$ May) showed higher seed yields. In considering these results, low seeding rate and early seeding time is important for getting high camelina seed yields.

A comparison of supplemental calcium soap of palm fatty acids versus tallow in a corn-based finishing diet for feedlot steers

  • Warner, Crystal M.;Hahm, Sahng-Wook;Archibeque, Shawn L.;Wagner, John J.;Engle, Terry E.;Roman-Muniz, Ivette N.;Woerner, Dale;Sponsler, Mark;Han, Hyungchul
    • Journal of Animal Science and Technology
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    • v.57 no.6
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    • pp.25.1-25.7
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    • 2015
  • Rumen bypass fat is commonly added to increase energy intake in dairy cattle. The objective of this study is to examine the addition of rumen bypass fat during finishing period on performance and carcass characteristics in grain fed steers. This study was conducted as a completely randomized block design with 126 cross-bred steer calves (initial BW $471.5{\pm}7.5kg$) randomly assigned to pens with 9 steers/pen (n = 7 pens/treatment). Each pen was randomly assigned to one of two treatment groups; rumen bypass fat treatment (CCS, calcium soap of palm fatty acids) and control diet (CT, tallow). The diets were formulated to be isonitrogenous and isocaloric. Animals were fed twice daily at 110 % of the previous daily ad libitum intake. Blood from each sample was taken from the jugular vein. Muscle and adipose samples were collected from the longissimus dorsi regions. Feedlot performance and carcass characteristics were assessed. To examine adipogenic gene expression, quantitative real-time PCR was completed. Steers fed the CT had a greater level of performance for most of the parameters measured. The CT group had greater DMI (P < 0.05) and tended to have greater ADG (P < 0.10). Marbling score (P < 0.05) and quality grade (P < 0.05) were greater for steers fed the CT diet than those fed CCS. The longissimus muscle area tended to be greater (P < 0.10) in steers fed CT ($87.60cm^2$) than those fed CCS (84.88 cm2). The leptin mRNA expression was down-regulated (P < 0.05) in adipose tissue of steers fed a CCS when compared to those fed CT. These data suggest that calcium soap of palm fatty acids can be added to finishing diets without significant reduction in final body weight, although there may be modest reductions in marbling and quality scores.