• Title/Summary/Keyword: 논문 요약

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Characteristics of Hydrodynamics, Heat and Mass Transfer in Three-Phase Inverse Fluidized Beds (삼상 역 유동층의 수력학, 열전달 및 물질전달 특성)

  • Kang, Yong;Lee, Kyung Il;Shin, Ik Sang;Son, Sung Mo;Kim, Sang Done;Jung, Heon
    • Korean Chemical Engineering Research
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    • v.46 no.3
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    • pp.451-464
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    • 2008
  • Three-phase inverse fluidized bed has been widely adopted with its increasing demand in the fields of bioreactor, fermentation process, wastewater treatment process, absorption and adsorption processes, where the fluidized or suspended particles are small or lower density comparing with that of continuous liquid phase, since the particles are frequently substrate, contacting medium or catalyst carrier. However, there has been little attention on the three-phase inverse fluidized beds even on the hydrodynamics. Needless to say, the information on the hydrodynamics and transport phenomena such as heat and mass transfer in the inverse fluidized beds has been essential for the operation, design and scale-up of various reactors and processes which are employing the three-phase inverse beds. In the present article, thus, the information on the three-phase inverse fluidized beds has been summarized and reorganized to suggest a pre-requisite knowledge for the field work in a sense of engineering point of view. The article is composed of three parts; hydrodynamics, heat and mass transfer characteristics of three-phase inverse fluidized beds. Effects of operating variables on the phase holdup, bubble properties and particle fluctuating frequency and dispersion were discussed in the section of hydrodynamics; effects of operating variables on the heat transfer coefficient and on the heat transfer model were discussed in the section of heat transfer characteristics ; and in the section of mass transfer characteristics, effects of operating variables on the liquid axial dispersion and volumetric liquid phase mass transfer coefficient were examined. In each section, correlations to predict the hydrodynamic characteristics such as minimum fluidization velocity, phase holdup, bubble properties and particle fluctuating frequency and dispersion and heat and mass transfer coefficients were suggested. And finally suggestions have been made for the future study for the application of three-phase inverse fluidized bed in several available fields to meet the increasing demands of this system.

The NACUFOK Business Consulting's Influence on the Management Performance of the Primary Credit Unions (신협중앙회 경영컨설팅이 단위신협의 경영성과에 미치는 영향)

  • Kang, Seong Moo;Ryu, Duk Wi
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.7 no.4
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    • pp.101-112
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    • 2012
  • Business consulting which aims at advising overall management, comparative advantage in competitive environment, administration and so forth is deemed to be significant so that a credit union may flexibly respond to rapid and complicated financial environment. Accordingly, business consulting has been initiated and implemented in credit union since 2002, which seemingly leads to positive outcome to enhance its competitiveness. However, very few research exists which analyze the credit union's competitiveness and business performance after the business consulting. Thus, the research intends to verify how consulting influences on management performance by its various factors. With the above studies in mind, hypothesis is formed that the characteristics of a consulting comsumer and the characteristics of supplier will give a meaningful impact on management performance. The test shows the result as followings: Firstly, a primary credit union's trust and NACUFOK's expertise demonstrate that they are closely relevant to financial and non financial management performance. Secondly, support and willingness to apply states that they influences on non financial performance, while no direct impact is found to financial performance. Thirdly, NACUFOK's capability is rarely interrelated to financial and non financial performance. The present study implies that the credit union as a consulting beneficiary should participate in the consulting, accept the result, and make effort to solve the management problems. In addition, NACUFOK as a consulting supplier should initiate the organization in exclusive charge, perform the professional group, and foster the professional consultant for the development of consulting method, the improvement of consulting process, and the specialization of consultant including the enhancement of core competencies. When these perspectives are sufficient, it will be connected to the management outcomes, further, it will be boosted up the competitiveness of the Credit Union. Hopefully the present study helps to motivate the consulting of primary credit union, boost up the effectiveness of consulting, further, providing the perspective on consulting the credit union. And these may result in the indication of consulting development direction and the competitiveness of Credit Union.

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Effects of Regular Treadmill Running on GLUT4 Protein of Skeletal Muscle in STZ-diabetic Rats (STZ-당뇨 흰쥐에서 규칙적인 Treadmill운동이 골격근 제 4 형 당수송체에 미치는 영향)

  • Kim, Jong-Yeon;Bae, Hyung-Il;Park, So-Young;Kim, Yong-Woon;Lee, Suck-Kang
    • Journal of Yeungnam Medical Science
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    • v.15 no.2
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    • pp.341-349
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    • 1998
  • The purpose of this study was to investigate the effects of regular treadmill running on GLUT4 protein of skeletal muscle in STZ-diabetic rats. I used 19 male Sprague-Dawley rats weighing 140 to 160 grams. Rats were randomly assigned into normal, diabetes(DM) and DE(DE) groups. The exercise was loaded with treadmill running for 5 days per week during 4 weeks. All experimental procedures were carried out following overnight fasting 48 hours after last exercise. Gain(gm) in body weight in DM rats(822.4) was lowered compared to normal rats(1092.8), and decreased by exercise. Plasma glucose concentration(mg/dl) in DM rats was 1433.1 which is higher than that of normal group of 1036.4. The concentration of DE group was lower than that of DM rats. Plasma insulin concentration(${\mu}U/ml$) of DM and DE rats was significantly lowerd compared to normal rats. There was no difference of plasma concentrations of FFA and HDL cholesterol among noraml, DM and DE groups. Plasma triglyceride concentration(mg/dl) was significantly highered in DM group compared to those of DM group, the concentration of DE group was lower. Glycogen concentration(mg/gm wet weight) of the plantaris muscle in DM and DE groups was significantly reduced compared to normal group. Glucose transporter 4(GLUT4) protein of soleus was analyzed by Western blot. In DM group, the GLUT4 protein level was markdly decreased compared to normal group, but the level was recovered to the level of normal group by 4 weeks treadmill running. In conclusion, the insulin resistance induced by STZ administration was partially improved by 4 weeks physical training in rats.

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A Study on the possibility about genre extension of korean verse and modern novel in Multimedia age (다매체시대, 시조와 현대소설을 통한 장르 확장의 가능성 고찰 - 생태학적 상상력을 중심으로 -)

  • Hur, Man-Ook
    • Sijohaknonchong
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    • v.25
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    • pp.75-100
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    • 2006
  • This treatise puts with ecology that important topic is becoming in Multimedia age today. Is appearing to some meaning that symbol that. Is nature friendship and nature assimilation in korean verse and modern novel. And is the purpose to draw diachronic and synthetic thought between age and genre is forming by ecological imagination how. Our korean verse thinks of nature as residing space, and is singing life that is nature friendship and nature assimilation in relation of indivisibility sto of human and nature. And nature space of metaphor or symbol is forming by ecological imagination in the modern novel. Therefore, these two genres see that traffic is available in diachronic synthetic relation. First, must escape resolutely in ideas that literature is basing in actuality and search the literature-ecological imagination. Therefore, forward literature may have to look for the literature-ecological imagination with many interests to green literature ecology and show image that move constantly. And must approach appearing common view of nature and the literature-ecological imagination in principle of integration of expropriation and production now all round to our literary productions. Therefore, must do so that can be nature friendship and become practical education model that expropriation of ecological literary productions and production activity foster literary sensibility and imagination. Also, lively research and groping about each genre of a Korean literature are to premised in diachronic and synthetic veins I will. Method groping that adapt on New Age as defending peculiar special quality that founder is keeping korean verse with opened thinking may have to be spread more hard. Therefore, genre of novel can may ready the one clue to grope confrontation method naturally to secure new identity in new literature environment of digital age.

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Korea and Japan Comparison Study of Distribution Industry: Focus on Input-out Analysis (유통산업의 한일비교 연구 - 산업연관분석을 중심으로 -)

  • Jho, Kwang-Hyun
    • Journal of Distribution Research
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    • v.16 no.5
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    • pp.171-192
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    • 2011
  • This paper focuses on the retail industry of industrial share of the GDP, productivity of distribution industry and input-out analysis between Korea and Japan, also results are summarized as follows. First, the share of GDP in agriculture, forestry and fisheries of the both countries is falling. That of manufacture increases in South Korea, while Japan is falling. While distribution industry shows vice versa. Employed population by industry is falling both countries also. The relative labor productivity shows that agriculture, forestry and fisheries, retail industry needs more labor, while manufacture has been met for both countries. Second, compare to Japan, the retail industry of Korea has been increased since 1990. Likewise, overall productivity of distribution industry in Korea has been increased while almost that of Japan has declined. Third, production inducement effects of Japan are greater than that of Korea. On the other hand, import inducement effects show vice versa. Fourth, as shown from the final demand of distribution industry and the rate of dependence on production inducement, we can see that the “increase in stocks” increases while gross government fixed capital formation shows vice versa. Korea's private consumption expenditure increases while Japan shows versa. South Korea's government consumption expenditure and exports are rising, on the other hand, that of Japan is declining. Fifth, the rate of dependence on distribution industry and import inducement shows the same tendency from both countries. As we can see from the private consumption expenditure, government consumption expenditure, gross government fixed capital formation, gross private fixed capital formation, increase in stocks, the rate of dependence on import inducement is more effective than the rate of dependence on production inducement. While the exports are comparatively ineffective. Sixth, the degrees of influence of retail industry are similar between Korea and Japan, while sensitivity of the Korean industry has been weakened. In this sense, strong policies are needed to boost the industry. Seventh, the investments in the retail industry of Korea showed the public-led trend, while Japan showed private sector-led investment trend. The investment trend of Korea's retail industry will be switched into private sector-led investment step by step in the future. This finding will be an important clue to set the policy direction of Korea distribution industry. Finally, both Korea and Japan are still in need of employment in retail industry. Not addressed in this paper, such as value-added-induced effects, employment inducement effect, will be remaining challenges in the following paper.

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Effects of the Oriental Medicinal Prescriptions, Jahyulyangeuntang and Yanghyuljangeunkeonbohwan, on Calcium Absorption in the Human Colon Carcinoma Cell Line (Caco-2 Cells) (자혈양근탕 및 양혈장근건보환이 인체 소장 상피세포주 (Caco-2) 모델에서 칼슘 흡수에 미치는 영향)

  • 박태선;임현정;황귀서
    • Journal of Nutrition and Health
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    • v.35 no.4
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    • pp.446-453
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    • 2002
  • Effects of the two oriental medicinal prescriptions, Jahyulyangeuntang (JH) and Yanghyuljangeunkeonbohwan (YH), on intestinal calcium absorption were examined in the human colon carcinoma tell line, Caco-2 cells. Intestinal calcium absorption was evaluated at the level of Ca uptake into the cells across the brush border membranes, as well as at the level of net Ca transport (implying the amount of intestinal Ca transported into the blood stream). When the Caco-2 cells were incubated for 4, 8, 16 and 24 days post seeding, the cells were differentiated continuously, and showed progressively increased activities of Ca uptake (1.13 $\pm$ 0.04, 1.19 $\pm$ 0.02, 1.94 $\pm$ 0.03, and 2.40 $\pm$ 0.12 nmole.mg protein$^{-1}$ .30 min$^{-1}$ , respectively). Pretreatment of confluent Caco-2 cells with 50 $\mu\textrm{g}$/ml of YH for 24 hours resulted in a 30% increase in Ca uptake (p < 0.07), while pretreatment of the cells with the same concentration of JH for 6 hours resulted in a 24% increase (p < 0.05) in Ca uptake, compared to the value for the control cells (2.34 $\pm$ 0.10 nmole.mg protein$^{-1}$ .30 min$^{-1}$ ). When the cells were pretreated with varied concentrations (5-100 $\mu\textrm{g}$/ml) of the test samples for 6 hours, maximal increases in Ca uptake were observed in the cells pretreated with 100 $\mu\textrm{g}$/ml of YH (a 23% increase), and 50 $\mu\textrm{g}$/ml of JH (a 28% increase), respectively : however, no influence was seen on the net Ca transport activity. These results show that pretreatment with JH or YH, the two oriental medicinal prescriptions commonly used for improvement of bone metabolism, could possibly increase Ca accumulation inside the cells. but not the intestinal Ca net transport in vitro.

The Mediating Effect of permissiveness of Sexual violence on Correlation between College students' stereotypes of Gender role and Experience of Sexual Violence Ability : Surveying residing in Jeju (대학생의 성역할 고정관념과 성폭력피해경험과의 관계에서 성폭력 허용도의 매개효과 : 제주지역 중심으로)

  • Kang, Cha-Sun;Park, Jung-Hwan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.8
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    • pp.273-279
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    • 2016
  • The purpose of this study was to examine the mediating effects of permissiveness of sexual violence on the relationship between gender role stereotypes and experience of sexual violence. The survey for this study was administered to 408 (male, 127, female, 281) out of the 600 university students residing in Jeju with the inventory of gender role stereotypes and experience of sexual violence in (conjunction with the) permissiveness of sexual violence scale. The results of this study were as follows: First, as a result of the correlation analysis, gender role stereotypes and experience of sexual violence were positively correlated with permissiveness of sexual violence. Second, the relationship analysis by Structural Equation Modeling demonstrated that permissiveness of sexual violence completely mediated the relationship between stereotypes of gender role and experience of sexual violence. Permissiveness of sexual violence was the most significant factor giving rise to sexual violence in dating. In the investigation of the structure of the equation coefficients and path-mediated effects, the standardized path coefficients of influence in this study, viz. gender role stereotypes to permissiveness (29, p=.000) of sexual violence and permissiveness of sexual violence to the experience of sexual violence (42, p=.000), were found to have an impact. In an indirect effect on the effectiveness of the parameters showed in gender role stereotypes and experience of sexual violence (11, p=.01), direct effects were demonstrated from stereotypes of gender role to permissiveness of sexual violence (28, p=.000) and from permissiveness of sexual violence to experience of sexual violence (40, p=.000). In the end, this implies that gender role stereotypes does not influence permissiveness of sexual violence directly, but indirectly by mediating the experience of sexual violence. Therefore, the implication of this study is that gender role stereotypes and permissiveness of sexual violence need to be reduced, so that sexual violence can be prevented. In other words, a higher awareness of gender equality will lower permissiveness of sexual violence and this, in turn, will also prevent sexual violence.

Assessment of Optimum Hydraulic Retention Time (HRT) for Maximum Biogas Production and Total Volatile Solid (TVS) Removal Efficiency of Semi-Continuously Fed and Mixed Reactor (SCFMR) Fed with Dairy Cow Manure (젖소분뇨로부터 최대 바이오가스 생산과 유기물 제거효율을 달성하기 위한 반건식 간헐주입 연속혼합 혐기성반응조의 최적 수리학적 체류시간 도출을 위한 연구)

  • Kang, Ho;Kim, Sun-Woo;Jeong, Ji-Hyun;Ahn, Hee-Kwon;Jung, Kwang-Hwa
    • Journal of Korean Society of Environmental Engineers
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    • v.37 no.12
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    • pp.696-704
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    • 2015
  • This study was carried out to evaluate the optimum operational condition of Semi-continuously Fed and Mixed Reactor (SCFMR) to treat the dairy cow manure and saw dust mixture. Step-wise increase in organic loading rates (OLRs) or decrease in hydraulic retention times (HRTs) were utilized until the biogas volume became significantly decreased at mesophilic temperature ($35^{\circ}C$). The optimum operating condition of the SCFMR fed with TS 13% dairy cow manure and saw dust mixture was found to be an HRTs of 25 days and its corresponding OLRs of $4.45kg\;VS/m^3-day$. At this condition the biogas and methane production rates were 1.44 v/v-d and 1.12 v/v-d (volume of biogas per volume of reactor per day), respectively and the TVS removal efficiency of 37% was achieved. The successful operation with such a high OLR was due to the high reactor alkalinity concentration of 14,500~15,600 mg/L as $CaCO_3$ as a result of the characteristic of the original substrate, dairy cow manure and saw dust mixture whose alkalinity was more than 8,000 mg/L as $CaCO_3$. The parameters for the reactor stability, the ratios of volatile acids and alkalinity concentrations (V/A) and the ratio of propionic acid and acetic acid concentrations (P/A) appeared to be 0.11 and 0.43, respectively, that were greatly stable in operation. Free ammonia toxicity was not experienced due to the long term acclimation by the reactor TS content ranged 7.2~10.4% during the entire operational period.

Role of Ghrelin in the Control of Reproductive Endocrine Function (포유류 생식 내분비 기능 조절에서 Ghrelin의 역할)

  • Lee, Sung-Ho
    • Development and Reproduction
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    • v.13 no.4
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    • pp.207-215
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    • 2009
  • Numerous factors can affect the activities of hypothalamus-pituitary-gonad (HPG) hormonal axis, resulting in alteration of reproductive capacity or status such as onset of puberty and menopause. Soon after the finding of leptin, a multifunctional hormone secreted from adipocytes, a close relationship between reproduction and body energy balance have been manifested. Ghrelin, another multifunctional hormone from gastrointestinal tract, is an endogenous ligand of growth hormone secretagogue receptor (GHSR), and is thought to be a counterpart of leptin in the regulation of energy homeostasis. As expected, ghrelin can also modulate the reproductive capacity through the modulation of activities of HPG axis. This paper summarizes the current knowledge on the discovery, gene structures, tissue distribution and roles of ghrelin and GHSRs in mammalian reproduction in particular modulation of reproductive hormone secretion in HPG axis. Like POMC gene expression in pituitary gland, preproghrelin gene can generate a complex repertoire of transcripts which further undergo alternative splicing and posttranslational modifications. Concerning the roles of preproghrelin gene products in the control of body physiology except energy homeostasis, limited knowledge is available so far. Several lines of evidence, however, show the interplay of ghrelin between metabolism and reproduction. In rat and human, the distribution of ghrelin receptor GHSRs (GHSR1a and GHSR1b) has been confirmed not only in the hypothalamus and pituitary which were originally postulated as target of ghrelin but also in the testis and ovary. Expression of the preproghrelin gene in the brain and gonads was also verified, suggesting the local role (s) of ghrelin in HPG axis. Ghrelin might play a negative modulator in the secretions of hypothalamic GnRH, pituitary gonadotropins and gonadal steroids though the action on pituitary is still questionable. Recent studies suggest the involvement of ghrelin in regulation of puberty onset and possibly of menopause entry. It is now evident that ghrelin is a crucial hormomal component in 'brain-gut' axis, and is a strong candidate links between metabolism and reproduction. Opposite to that for leptin, ghrelin signaling is likely representing the 'hunger' state of body energy balance and is necessary to avoid the energy investment into reproduction which has not a top priority in maintaining homeostasis. Further researches are needed to gain a deep insight into the more precise action mechanism and role of ghrelin in reproduction, and to guarantee the successful biomedical applications.

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Classification of Domestic Freight Data and Application for Network Models in the Era of 'Government 3.0' ('정부 3.0' 시대를 맞이한 국내 화물 자료의 집계 수준에 따른 분류체계 구축 및 네트워크 모형 적용방안)

  • YOO, Han Sol;KIM, Nam Seok
    • Journal of Korean Society of Transportation
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    • v.33 no.4
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    • pp.379-392
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    • 2015
  • Freight flow data in Korea has been collected for a variety of purposes by various organizations. However, since the representation and format of the data varies, it has not been substantially used for freight analyses and furthermore for freight policies. In order to increase the applicability of those data sets, it is required to bring them in a table and compare for finding the differences. Then, it is shown that the raw data can be aggregated by a particular criterion such as mode, origin and destination, and type commodity. This study aims to examine the freight data issue in terms of three different points of view. First, we investigated various freight volume data sets which are released by several organizations. Second, we tried to develop formulations for freight volume data. Third, we discussed how to apply the formulations to network models in which particular OR (Operations Research) techniques are used. The results emphasized that some data might be useless for modeling once they are aggregated. As a result of examining the freight volume data, this study found that 14 organizations share their data sets at various aggregation levels. This study is not an ordinary research article, which normally includes data analysis, because it seems to be impossible to conduct extensive case studies. The reason is that the data dealt in this study are diverse. Nevertheless, this study might guide the research direction in the freight transport research society in terms of data issue. Especially, it can be concluded that this study is a timely research because the governmemt has emphasized the importance of sharing data to public throughout 'government 3.0' for research purpose.