• Title/Summary/Keyword: Formation and Performance

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Evaluation of Characteristics of G-class Cement for Geothermal Well Cementing (지열 발전정 시멘팅을 위한 G-class 시멘트 특성 평가에 관한 연구)

  • Won, Jongmuk;Jeon, Jongug;Park, Sangwoo;Choi, Hangseok
    • Journal of the Korean Geotechnical Society
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    • v.29 no.5
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    • pp.29-38
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    • 2013
  • The G-class cement is commonly used in practice for geothermal well cementing in order to protect a steel casing that is designed to transport hot water/steam from deep subsurface to ground surface during operating a geothermal power plant. In order to maintain optimal performance of geothermal wells, physical properties of the cementing material should be satisfactory. In this paper, relevant factors (i.e., groutability, uniaxial compression strength, thermal conductivity and free fluid content) of the G-class cement were experimentally examined with consideration of various water-cement (w/c) ratios. Important findings through the experiments herein are as follows. (1) Groutability of the G-class cement increases by adding a small dose of retarder. (2) There would be a structural defect caused when the w/c ratio is kept higher in order to secure groutability. (3) Thermal conductivity of the G-class cement is small enough to prevent heat loss from hot steam or water to the outer ground formation during generating electricity. (4) The G-class cement does not form free water channel in cementing a geothermal well. (5) The Phenolphthalein indicator is applicable to the distinction of the G-class cement from the drilling mud.

Influence of Brand Origin Related Perception on Brand Performance Variables (브랜드 원산지에 대한 인식이 브랜드 성과관련 변수에 미치는 영향)

  • Kim, Kee-Hun;Kim, Moon-Tae
    • Management & Information Systems Review
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    • v.37 no.4
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    • pp.219-236
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    • 2018
  • The purpose of this study is to investigate the effect of image of brand origin on brand related variables in the formation of attitude or loyalty of global brand, We tried to identify more influential relationships through sub-variables such as brand familiarity, brand identification, and brand attitude. This study presents the following results and implications. It is shown that the manufacturing ability image has no direct effect on brand identification, but the general image has a direct positive effect on brand identification. In addition, the manufacturing capability image and general image of brand origin have indirect effects on brand familiarity through brand identification without directly affecting brand familiarity. In addition, consumers are more likely to be more familiar with brands that they think are consistent with their own images, maintain a good attitude, and be more likely to be loyal to brands. Brand familiarity had a positive effect on brand attitude but not on brand loyalty. Familiarity showed a positive attitude, but it did not necessarily lead to strong repeat purchase or purchase.

Effect of Intermittent Plasma Discharge on the Hydrocarbon Selective Catalytic Reduction of Nitrogen Oxides (간헐적 플라즈마 방전이 질소산화물의 탄화수소 선택적 촉매환원에 미치는 영향)

  • Kyeong-Hwan Yoon;Y. S. Mok
    • Applied Chemistry for Engineering
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    • v.34 no.5
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    • pp.507-514
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    • 2023
  • The selective catalytic reduction (SCR) of nitrogen oxides (NOx) was investigated in a catalyst (Ag/γ-Al2O3) packed dielectric barrier discharge plasma reactor. The intermittent generation of plasma in the catalyst bed partially oxidized the hydrocarbon reductant for NOx removal to several aldehydes. Compared to using the catalyst alone, higher NOx conversion was observed with the intermittent generation of plasma due to the formation of highly reductive aldehydes. Under the same operating conditions (temperature: 250 ℃; C/N: 8), the NOx reduction efficiencies were 47.5%, 92%, and 96% for n-heptane, propionaldehyde, and butyraldehyde, respectively, demonstrating the high NOx reduction capability of aldehydes. To determine the optimal condition for intermittent plasma generation, the high voltage on/off cycle was adjusted from 0.5 to 3 min. The NOx reduction performance was compared between continuous and intermittent plasma generation on the same energy density basis. The highest NOx reduction efficiency was achieved at 2-min high voltage on/off intervals. The reason that the intermittent plasma discharge exhibited higher NOx reduction efficiency even at the same energy density, compared to the continuous plasma generation case, is that the intermediate products, such as aldehydes generated from hydrocarbon, were more efficiently utilized for the reduction of nitrogen oxides.

The Electrochemical Property Studies on Polyacenic Semiconductor Anode Material (음극 폴리아센 반도체 재료의 전기화학적 특성연구)

  • Kim Han-Joo;Park Jong-Eun;Son Won-Keun;Lee Hong-Ki;Park Soo-Gil;Lee Ju-Seong
    • Journal of the Korean Electrochemical Society
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    • v.2 no.3
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    • pp.134-137
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    • 1999
  • The polyacenic semiconductor material (PAS) electrode prepared by the pyrolytic treatment of phenol-formaldehyde resin is one of useful electrodes. As an anode material of lithium rechargeable batteries, amorphous carbon materials have been studied extensively because of their high electrochemcal performance and cyclicability. Carbon materials do not lead to the formation of lithium dendrite which is one of the most serious problems in applying Li-based materials to an electrode of batteries. The polyacene materials prepared from phenol resin at relatively low temperatures $(550\~750^{\circ}C)$ show a highly Li\doped state up to $C_2Li$ state without liberation of Li cluster. We prepared each polyacene materials at various temperature and investigated electro- chemical properties. We tried to change the mole ratio of [H]/[C] which is $0.24\~0.4$ range. Considering of electrochemical properties of PAS material, the PAS material is one of the most suitable materials for electrodes of a polymer battery.

Achievement of Color Constancy by Eigenvector (고유벡터에 의한 색 일관성의 달성)

  • Kim, Dal-Hyoun;Bak, Jong-Cheon;Jung, Seok-Ju;Kim, Kyung-Ah;Cha, Eun-Jong;Jun, Byoung-Min
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.5
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    • pp.972-978
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    • 2009
  • In order to achieve color constancy, this paper proposes a method that can detect an invariant direction that affects formation of an intrinsic image significantly, using eigenvector in the $\chi$-chromaticity space. Firstly, image is converted into datum in the $\chi$-chromaticity space which was suggested by Finlayson et al. Secondly, it removes datum, like noises, with low probabilities that may affect an invariant direction. Thirdly, so as to detect the invariant direction that is consistent with a principal direction, the eigenvector corresponding to the largest eigenvalue is calculated from datum extracted above. Finally, an intrinsic image is acquired by recovering datum with the detected invariant direction. Test images were used as parts of the image data presented by Barnard et al., and detection performance of invariant direction was compared with that of entropy minimization method. The results of experiment showed that our method detected constant invariant direction since the proposed method had lower standard deviation than the entropy method, and was over three times faster than the compared method in the aspect of detection speed.

Reconsideration of the Formation Process of Current Nagyangchun (현행 낙양춘의 형성과정 재고)

  • Yim, Hyun-taek
    • (The) Research of the performance art and culture
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    • no.43
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    • pp.79-120
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    • 2021
  • Nagyangchun is a Dangak that has been handed down to the present time with Boheoja as a Saak of the Song Dynasty which was introduced in the Goryeo Dynasty. The title and lyrics of Nagyangchun are conveyed in the Dangakjo of Goryeosa-akji and the Jeungbomunheonbigo. The remaining scores containing Nagyangchun include Akjangyoram, Sogagwonbo Vol.4 and Vol.6 of the Joseon Dynasty and Aakbu-akbo, the 6th Aaksaeng-gyogwacheol, Leewangjikaakbu-oseonakbo during the Japanese colonial period. Besides, the current melody of Nagyangchun is based on Hangugeumak and Gugakjeonjib published by the National Gugak Center. This paper aims to examine how Nagyangchun, which is currently being performed at the National Gugak Center, went through the process of change to have the same structure and form as it is now using these scores as a research subject. The study results are summarized as follows. First, the song of Nagyangchun, which was originally Saak but transmitted as an instrumental piece without lyrics, first appeared in the Hangugeumak Vol.16 and Gugakjeonjib Vol.7 published by the National Gugak Center in 1978 and 1979. In this process, the Janggu added by Kim Ki-soo is now disappearing and is replaced by Jwago. Second, though the five notes of 黃, 太, 仲, 林, and 南 have been maintained unchanged since the Akjangyoram, the pitch of 無/應 and 夾/姑, which appear once each, gradually rises and is unified into 應 and 姑 during the period of Aaksaeng-gyogwacheol or at the latest Leewangjikaakbu-oseonakbo, and reached the present. Third, the current melody of Nagyangchun consists of a structure in which the tones and range of each phrase rises within the form of Mijeonsa (a·b·c·d) and Mihusa (e·b'·c'·d'). Particularly, except for the a-type and e-type melodies, which are the introduction for the Mijeonsa and Mihusa, the remaining melodic types show a gradually descending structure within the corresponding phrase, so the structure of ascending and descending is generally in harmony. Forth, the Ganeum that appeared from Aakbu-akbo are currently classified into seven types, and they appear in ascending pitches of 2nd, 3rd, 4th, and 5th and play a role in smoothly or fluently connecting melodic progression. Fifth, after Akjangyoram, Nagyangchun, which had been handed down as an instrumental piece without lyrics, was restored in 1960 by Lee Hye-gu, and is being passed down as the form of male and female vocals added to the instrumental accompaniment. As a result of examining the current Nagyangchun, which was formed through the process of change after Akjangyoram, it was found that there were tasks that required reconsideration of the current Nagyangchun, which is being played at the National Gugak Center, such as the arrangement of Janggu, the identification of the key, and the investigation of the lyrics. When follow-up studies are continued in the future, it will be able to contribute to the cultural transmission of Nagyangchun.

Occupational Stress of Hospital Workers (병원종사자의 직업성 스트레스에 관한 연구 - 서울시내 500병상 이상 병원종사자를 중심으로 -)

  • Lee, Woo-Cheon
    • Korea Journal of Hospital Management
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    • v.3 no.1
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    • pp.1-33
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    • 1998
  • The purpose of this thesis is to study theoretical access to the methods that have been used for the research of occupational stress, thereby providing management methods of occupational stress of hospital workers. With a stress model of hospital workers set up from the viewpoint of organization management, 929 sets of questionnaires were collected from intern doctors, resident doctors, nurses, nursing aides, pharmacists, medical technicians, workers in patient affairs(reception and medical insurance workers), administrators and clerks from the 8 hospitals in Seoul with more than 500 beds. Upon variance analysis, correlation analysis and regression analysis of the collected questionnaires, this work examined how differences in stress caused by specific occupations and formulated a method of stress management for the hospital workers. The results are as follows. 1) If some duties of the nurses suffering from role-overloaded stress are transferred to the nursing aides dissatisfied with insufficient role, the two grunting groups can be satisfied at the same time. It is also necessary to transfer some jobs of the overloaded workers in patient affairs to the administrators, or the other way around. To reduce stress of conflict and ambiguity of role caused by the obscure division of roles between the workers, the role of each occupation should be delineated and the clear division of roles should be translated into action strictly according to that delineated. 2) Stress of inefficiency of organization from which the student doctors suffer can be relieved by management of participation. If they have access to the process of decision-making in general hospital affairs and consequently their understanding and the autonomy of job performance are promoted, such stress will be reduced. 3) To cope with stress of career development from which nurses, medical technicians, administrators, workers in patient affairs suffer, it is necessary to establish whether they have a chance to revive their careers, whether there are any ways of remotivation for less contributive workers, and whether they encourage each other to develope their careers. If they are given a chance to develope their careers, such stress will be relieved. 4) Pharmacists, suffering from stresses of living and personal relations, have strong cohesive power among themselves and organize a well-integrated team; thereby reducing the stress of personal relations and increasing productivity. 5) For administrators and student doctors confined to lesser social supports and for nurses and workers in patient affairs whose recognition of stress and job satisfaction are affected by social supports, emotional and informational supports for job performance help alleviate an individual's mental, and physical stress. 6) In addition to the above-mentioned stress-management methods, if an organizational coping strategy is provided according to the types of stress from the general viewpoint of the whole group of hospital workers, it would be of great help to managing stress. For example, the redesign of jobs, the management of objective, the improvement of working environment, the formation of an autonomous working group and various working plans can be set up for those who suffer from stress related to inappropriate role, while career counseling and development of career process can be provided for those dissatisfied with career development. Participation in the process of decision-making and the restructuring of the organization are needed for those who suffer from stress of malfunctioning organization, whereas creation of a supportive organizational atmosphere is desired for those who feel stressed due to personal relations. As well, such organizational coping strategies. as the increase of welfare facilities, seminars and educational programs and provision of health-promotion facilities can be provided.

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Development and Application of Multi-Functional Floating Wetland Island for Improving Water Quality (수질정화를 위한 다기능 인공식물섬의 개발과 적용)

  • Yoon, Younghan;Lim, Hyun Man;Kim, Weon Jae;Jung, Jin Hong;Park, Jae-Roh
    • Ecology and Resilient Infrastructure
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    • v.3 no.4
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    • pp.221-230
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    • 2016
  • Multi-functional floating wetland island (mFWI) was developed in order to prevent algal bloom and to improve water quality through several unit purification processes. A test bed was applied in the stagnant watershed in an urban area, from the summer to the winter season. For the advanced treatment, an artificial phosphorus adsorption/filtration medium was applied with micro-bubble generation, as well as water plants for nutrient removal. It appeared that the efficiency of chemical oxygen demand (COD) and total phosphorus (T-P) removal was higher in the warmer season (40.9%, 45.7%) than in the winter (15.9%, 20.0%), and the removal performance (suspended solid, chlorophyll a) in each process differs according to seasonal variation; micro-bubble performed better (33.1%, 39.2%) in the summer, and the P adsorption/filtration and water plants performed better (76.5%, 59.5%) in the winter season. From the results, it was understood that the mFWI performance was dependent upon the pollutant loads in different seasons and unit processes, and thus it requires continuous monitoring under various conditions to evaluate the functions. In addition, micro-bubbles helped prevent the formation of anaerobic zones in the lower part of the floating wetland. This resulted in the water circulation to form a new healthy aquatic ecosystem in the surrounding environment, which confirmed the positive influence of mFWI.

Development of a Measuring Tool for Spiritual Care Performance of Hospice Team Members (호스피스 팀원들의 영적 돌봄 수행도 측정 도구 개발)

  • Yoo, Yang-Sook;Han, Sung-Suk;Lee, Sun-Mi;Seo, Min-Jeong;Hong, Jin-Ui
    • Journal of Hospice and Palliative Care
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    • v.9 no.2
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    • pp.86-92
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    • 2006
  • Purpose: This study was conducted to develop a measuring tool for spiritual care performance of hospice team members. The tool may be utilized for providing hospice patients with more systematic and standardized spiritual tares. Methods: The concept and questions of the tool were developed, and then its validity and reliability were tested. For the validity and reliability tests, a self-reported questionnaire comprising 33 questions with 4 point scale ($1{\sim}4$), was developed, and the data were collected from 192 hospice team members from December 2005 to February 2006. Results: Thirty three questions, drafted through literature review and professional consultation, were reviewed by 20 professionals for their validity, were revised and supplemented resulted in the final 33 questions. The questions with a correlation coefficient grater than .30 were selected: all the 33 questions were selected based on this criterion. The reliability coefficient, Cronbarh's ${\alpha}$, was 0.95. The 33 questions were analyzed for factors, and six factors were extracted: relationship formation and communication, encouragement and promotion of spiritual growth, linking with spiritual resources, preparation of death, evaluation and quality control for spiritual intervention, Intervention, and spiritual assessment for intervention. Conclusion: The tool developed in this study includes six factors and has high level of reliability. This tool Will greatly contribute to assess and improve hospice care services, providing systematic and standardized spiritual cares for terminally ill patients and their families.

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Effect of $Bio-Silverlite^{(R)}$ on Performance, Weight of Organ, Intestinal Villus and Intestinal Microbial in Broiler Chicks (브로일러 사료에 $Bio-Silverlite^{(R)}$의 첨가가 사양성적, 장기중량, 소장 Villus 및 장내 미생물 성상에 미치는 영향)

  • Kim C.H.;Lim K.C.;Hwang J.H.;Ra C.S.;Pak J.I.
    • Korean Journal of Poultry Science
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    • v.33 no.1
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    • pp.33-39
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    • 2006
  • This study was conducted to investigate the feeding effect of $bio-silverlite^{(R)}$ on growth performance, organ phenomenon and cecum microflora in broiler chicks. The $bio-silverlite^{(R)}$ was made by an ion exchange between illite and $silver(Ag^+)$. There were four treatment groups: negative control group(non-treatment), antibiotic supplement group (positive control), 0.5% $bio-silverlite^{(R)}$ supplment group and 1.5% $bio-silverlite^{(R)}$ supplement group. Total 200 birds was assigned for this five replication tests, allocating 10 birds into each treatment. Experimental diets were formulated on isocalories and isonitrogen for the whole experimental period. Body weight gain was higher in antibiotic supplementation (+C) and $bio-silverlite^{(R)}$ supplement groups(S 0.5% and 51.5%) than the negative control group(-C), and feed efficiency was significantly enhanced with increase of the level of $bio-silverlite^{(R)}$ supplement. The length of small intestine was longer in +C than in -C and $bio-silverlite^{(R)}$ supplement groups (P<0.05), and the weight of small intestine was proportional to the level of $bio-silverlite^{(R)}$ supplement. Crop weight was lower in $bio-silverlite^{(R)}$ supplement group than in -C and +C groups (P<0.05), and the cecum weight was heavier in $bio-silverlite^{(R)}$ supplementation group. Intestinal villi height was longer in 51.5% group at 3 weeks and 6 weeks of age than in -C and +C groups. With the respect of the formation of intestinal microflora, TBC and CBC was not affected by age and feed additive. However, the number of LAB was slightly higher in $bio-silverlite^{(R)}$ supplement group than in -C and +C groups.