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Recent Progress in Air-Conditioning and Refrigeration Research: A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2014 (설비공학 분야의 최근 연구 동향: 2014년 학회지 논문에 대한 종합적 고찰)

  • Lee, Dae-Young;Kim, Sa Ryang;Kim, Hyun-Jung;Kim, Dong-Seon;Park, Jun-Seok;Ihm, Pyeong Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.27 no.7
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    • pp.380-394
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    • 2015
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2014. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of heat and mass transfer, cooling and heating, and air-conditioning, the flow inside building rooms, and smoke control on fire. Research issues dealing with duct and pipe were reduced, but flows inside building rooms, and smoke controls were newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for thermal contact resistance measurement of metal interface, a fan coil with an oval-type heat exchanger, fouling characteristics of plate heat exchangers, effect of rib pitch in a two wall divergent channel, semi-empirical analysis in vertical mesoscale tubes, an integrated drying machine, microscale surface wrinkles, brazed plate heat exchangers, numerical analysis in printed circuit heat exchanger. In the area of pool boiling and condensing, non-uniform air flow, PCM applied thermal storage wall system, a new wavy cylindrical shape capsule, and HFC32/HFC152a mixtures on enhanced tubes, were actively studied. In the area of industrial heat exchangers, researches on solar water storage tank, effective design on the inserting part of refrigerator door gasket, impact of different boundary conditions in generating g-function, various construction of SCW type ground heat exchanger and a heat pump for closed cooling water heat recovery were performed. (3) In the field of refrigeration, various studies were carried out in the categories of refrigeration cycle, alternative refrigeration and modelling and controls including energy recoveries from industrial boilers and vehicles, improvement of dehumidification systems, novel defrost systems, fault diagnosis and optimum controls for heat pump systems. It is particularly notable that a substantial number of studies were dedicated for the development of air-conditioning and power recovery systems for electric vehicles in this year. (4) In building mechanical system research fields, seventeen studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, and renewable energies, piping in the buildings. Proposed designs, performance performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the evaluation of work noise in tunnel construction and the simulation and development of a light-shelf system. The subjects of building energy were worked on the energy saving of office building applied with window blind and phase change material(PCM), a method of existing building energy simulation using energy audit data, the estimation of thermal consumption unit of apartment building and its case studies, dynamic window performance, a writing method of energy consumption report and energy estimation of apartment building using district heating system. The remained studies were related to the improvement of architectural engineering education system for plant engineering industry, estimating cooling and heating degree days for variable base temperature, a prediction method of underground temperature, the comfort control algorithm of car air conditioner, the smoke control performance evaluation of high-rise building, evaluation of thermal energy systems of bio safety laboratory and a development of measuring device of solar heat gain coefficient of fenestration system.

Spermatozoa Characteristics of Streptozotocin-induced Diabetic Wistar Rat: Acrosome Reaction and Spermatozoa Concentration (Streptozotocin으로 유발된 당뇨병성 Wistar Rat 정자의 첨체반응 및 수 변화 특성)

  • Cheon, Yong-Pil;Kim, Chung-Hoon;Kang, Byung-Moon;Chang, Yoon-Seok;Nam, Joo-Hyun;Kim, Young-Soo;Gye, Myung-Chan;Kim, Moon-Kyoo;Kim, Kil-Soo
    • Clinical and Experimental Reproductive Medicine
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    • v.26 no.1
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    • pp.89-96
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    • 1999
  • Some of the information concerning sexual function in the male diabetes has been focused upon the problems of endocrine or semen parameters. However, the characteristics of acrosome reaction and spermatozoa concentration at the epididymis and vas deferens have scarcely been studied, and the causes of the infertility has not been critically identified. So, we designed to inspect the spermatozoa concentration and the characteristics of acrosome reaction at epididymis and vas deferens of diabetic Wistar rat induced by streptozotocin (STZ, 70 mg/kg, ip). Experimental animal was sacrificed at 3 days and 14 days after the STZ injection. In the diabetes-induced rat, the levels of insulin and glucose had a pattern of inverse proportion. The spermatozoa concentrations in caput and corpus epididymis were significantly decreased in all diabetic condition. In cauda epididymis, however, there was significant decrease in sperm concentration at 14 days onward. In diabetic rat, the spontaneous reaction rate of spermatozoa of cauda and vas deferens were significantly higher than the control group. The ARIC (acrosome reaction to ionophore challenge) value of caudal sperm was 28.7 at control, 22.1 at 3 days, and 8.3 at 14 days. In the present study the spermatozoa concentration was decreased and the spontaneous reaction rate was increased by diabetes. In ARIC-test, it is revealed that the fertility of spermatozoa of 14 days group was lower than control or 3 days group. Diabetes mellitus may be provoke the decreased fertilization rate and subsequent infertility and subsequent infertility.

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A Comparative Study on Attitude of the Collegiate an4 Non-Collegiate Nursing Students toward Their Clinical Affiliation in a Mental Hospital (정신과 간호 실습에 대한 간호 대학생과 간호학교 학생들의 태도 비교 연구)

  • 김소야자
    • Journal of Korean Academy of Nursing
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    • v.4 no.2
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    • pp.17-31
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    • 1974
  • Today, over seventy five percent of nursing in Korea provide a psychiatric experience in the basic curriculum. The psychiatric affiliation presents numerous major problems of adjustment to the student. The Importance of positive attitude toward the nursing care of psychiatric patients is recognized by the nursing profession. I have fined out the unfavorable attitude of non collegiate nursing students toward psychiatric nursing affiliation by previous research. This study was undertaken in response to a felt need to explore the use of several devices which might yield information about attitudes toward psychiatric nursing as a basis for future planning of the program offered at a selected hospital. This study is designed to meet the following objectives; (1) In order to find out the expressed attitudes of fifty·three collegiate nursing students toward their psychiatric affiliation. (2) To compare responses given by selected group of collegiate and non collegiate nursing students to same questionnaire (3) To determine the relationship between the attitudes of nursing students toward psychiatric nursing and the type of instructions where experience was obtained. A questionnaire, a Korean translation of the "Psychiatric Nursing Attitude Questionnaire" by Moldered Elizabeth fletcher, was administered to fifty-three collegiate nursing students who had completed a four-week psychiatric affiliation in a S hospital psychiatric ward during May 7, 1973 to Dec. 16, 1973. - The questionnaire of 100 statements was administered in the following way; (1) Part Ⅰ, Preconceptions, was, given in individual conferences with each subject, during the first few days of their affiliation, and again during the final week of affiliation. The responses to Part I were oral. (2) Part Ⅱ, Expectations, Part Ⅲ, Personal Relations, Part Ⅳ, Personal Feelings, and Part V, Attitudes and Activities of Patients were given to all of the subjects in a group meeting during the second week of the affiliation, and again, during the fourth week at the termination of the affiliation. Responses to Parts Ⅱ, Ⅲ, Ⅳ·, and V, were written. Each of the 100 statements of the questionnaire was considered to be either Positive or Negative. A favorable response was assigned the positive value of 1 and an unfavorable response was assigned the Negative value of O. The coefficient of correlation was computed between the two sets of scores for the fifty-three nursing students, The mean score, the standard deviation, and the differences in the means on each of the five parts of the questionnaire were computed and the relationships calculated by at-test. The results of the study were as follows; 1. There was no significant correlation between the two sets of the scores for the fifty-three nursing students during the four-week psychiatric affiliation. (r= 0.36) 2. There was no significant difference in the mean scores between the first and final tests for any of the questionnaire. 3. The Part Ⅰ, Preconceptions, data indicated collegiate nursing students have positive attitudes in preconceptions than non collegiate nursing students and preconceptions toward the psychiatric affiliation which affect their psychiatric nursing experience. 4. The Part Ⅱ, Expectations, data indicated more appropriate expectations of collegiate nursing students related to pre psychiatric affiliation orientation and sufficient theory learning than non-collegiate nursing students. 5. The Part Ⅲ, Personal relations, data indicated some students have negative attitudes in personal relations with normal people in respect to psychological security and social responsibilities. 6. The Part Ⅳ, Personal feelings, data indicated nursing students have psychological insecurity & inappropriateness. 7. The Part V, Attitudes and activities of patients, data indicated collegiate nursing students have more positive attitudes to the psychotic behavior of certain situations due to sufficient theory learning. 8. The data indicated collegiate·nursing students have more positive attitude than non-collegiate nursing students. 5. The Part Ⅲ, Personal relations, data indicated some students have negative attitudes in personal relations with normal people in respect to psychological security and social responsibilities. 6. The Part Ⅳ, Personal feelings, data indicated nursing students have psychological insecurity & inappropriateness. 7. The Part V, Attitudes and activities of patients, data indicated collegiate nursing students have more positive attitudes to the psychotic behavior of certain situations due to sufficient theory learning. 8. The data indicated collegiate·nursing students have more positive attitude than non-collegiate nursing students through psychiatric affiliation.

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Lived Experience of patients with Terminal Cancer : Parses Human Becoming Methodology (말기 암환자의 체험에 관한 현상학적 연구)

  • 이옥자
    • Journal of Korean Academy of Nursing
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    • v.25 no.3
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    • pp.510-537
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    • 1995
  • Human health is an integral part of experience in the process of Human Becoming. Through continual interaction with the environment human beings freely choose experience and develop as responsible beings. The process of the health experience of patient with terminal cancer is a unique. he objective of this study is to understand the lived experience of patients with terminal cancer in order to provide basic information for nursing care in the clinical setting and to develop a theoretical background for clinical practice. This study is to de-scribe and define the lived experience of patients with terminal cancer in order to provide a foundation for nursing research and education. Data collection has been done between December 1993 and November 1994. The subjects included five persons -four females and one male : one who was in her sixties, one in his fifties, two in their forties, and one who was in her thirties. The researcher has met with these patients 35 times, but at eight times the patient was in a stuporous condition and not able to participate, so these were not included in the data analysis. Parse's "Human Becoming Methodology", an existential phenomenological research methodology is used for this study. Data has been collected using he dialogical engagement process of "I and You", the participant researcher and the participant subject. Dialogical engagement was discontinued when the data was theoretically saturated. Data was analyzed using the extraction - synthesis and heuristic interpretation. The criteria of Guba and Lincoln(1985). and Sandelo wski(1986) : credibility, auditability, fitness and objectivity were used to test the validity and reliability of the data. The following is a description of the structure of the lived experience of patients with terminal cancer as defined by this study : 1. Structure : 1) Suffering through the reminiscence of past experience 2) The appearance of complex emotions related to life and connectedness 3) The increasing importance of significant people and of the Absolute Being 4) The increasing realization of the importance of health and belief 5) Desire for a return to health and a peaceful life or for acceptance of dying and a comfortable death In summary the structure of the lived experience of these patients can be said to be : suffering comes through reminiscence of past experience, and there are complex emotions related to life and connectedness. Significant people and the Absolute Being become increasingly important along with a realization of the importance of health and faith. And finally there is a desire for either a return to health and a peaceful life or for the acceptance of dying and a comfortable death. 2. Heuristic Interpretation : Using Parse's Human Becoming Methodology, the structure of the lived experience of patients with terminal cancer identified in this research is interpreted as. The lived experience of patients with terminal cancer involves the solving of past conflicts, and the experience of the healing and valuing of sorrow and pain. Through the relation of life and health, and the complex emotions that arise, the lived experience of revealing - concealing is of paradoxical emotions. The increasing importance of significant others and of the Absolute Being shows Connecting and Separating an on- going process of nearness and farness. Revision of thoughts about health and faith is interpreted as transforming and desire for restoration to health and a peaceful life or acceptance of dying and a cowfortable death, as powering. In summary, it is possible to see, in the lived experience of patients with terminal cancer, the relationship of the five concepts of Parse's theory : valuing, revealing -concealing, connecting-separating, transforming, and powering. From Parse's theory, the results of this study show that meaning is related to valuing, rhythmicity to revealing-concealing and connect-ing-separating, and cotranscendence to transforming and powering.

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The Effect of Pulmonary T.B. Patients Self-Concept and Health Beliefs on Therapeutic Behavior (폐결핵 환자의 자아개념 (Self-Concept)과 건강신념(Health Beliefs)이 치료적 행위 이행에 미치는 영향)

  • 심영옥
    • Journal of Korean Academy of Nursing
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    • v.13 no.3
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    • pp.61-74
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    • 1983
  • The proportion of people who contacted pulmonary T.B. in Korea has drastically decreased as a result of the incessant effort of the Korean government which adopted a policy of“drive out T.B.”as its foremost health policy. However, the proportion still remains relatively high com-pared with that of developed countries. This study attempts to find some means for guiding and educating college students who have T.B. in their health care by (1) first determining the effect if their self-concept and health beliefs on their behavior in regard to their disease and (2) then predicting the level of compliance of the new patients to the treatment suggested by the health specialist, before the commencement of the treatment. The subjects of this study consisted of 88 mald and female students at Y University who were diagnosed as minimal pulmonary T.B. patients and registered at the health clinic of Y University during the period between September 1, 1981 and March 31, 1953. Data were collected from them by means of questionnaire and interview. The instruments used for this study were (1) a part of Junghoon Choi's“Perceptual Orientation ,Scale”for measuring self-perception of patients and (2) Rosenberg's questionnaire for measuring patients' evaluation of self-esteem, and (3) an instrument for measuring patients' health beliefs which was developed by this researcher utilizing information available from references. The collected data were analyzed using descriptive statistics, chisquare test, Pearson correlation coefficient and t-test. The findings were as follows: 3. Test of hypotheses 1) Hypothesis 1: Patients with high self-concept will be high in health beliefs. For testing this hypothesis a calculation of Pearson correlation coefficient (r) between the patients' self-concept and their health beliefs was carried out. The result of this test was -. 0756 which was not significant at α=.05 and hence hypothesis 1 was not supported. 2) Hypothesis 2: Patients with a high self-concept will tend to be high in compliance with the suggested treatment. Again a Pearson correlaton coefficient was calculated between the two variaibles in the hypothesis. The calculated coefficient r was .1558 which was not significant at α=.05. Hence hypothesis 2 was rejected. 3) Hypothesis 3: Patients with high susceptibility will have a high compliance level. The correlation coefficient between the two variables was -.1975, which was significant at α=.05 but due to the negative sign hypothesis 3 could not be accepted. 4) Hypothesis 4: Patients who take their disease seriously will have a higher compliance level. The calculated correlation coefficient between the variables in this hypothesis was .1642 which was not significant at α=.05 and hence hypothesis 4 was rejected. 5) Hypothesis 5: Patients with a high sense of the benefit of treatment will have a high level of compliance. The computed correlation coefficient was .3129 which was significant at α=.05 and hence hypothesis 5 was acepted. 2. Findings from the correlation analysis were as follows: 1) Patients' susceptibility and their compliance to treatment was negatively correlated (r= -. 1975) which was significant at α= .05. This implies that as the patients' level of susceptibility increases their compliance level decreases. 2) Patients' susceptibility and their self-concept were negatively correlated (r= -. 1790) which was again singnificant at α=.05. The implication of this is that as the patients’self concept increases their susceptibility to disease decreases. 3) Patients' self-concept and their sense of benefit derieved from the treatment was positively correlated (r=.1970) which was significant at α=.05. That is, patients with a high self-concept perceived a great sense of benefit from the treatment. To summarize, patients who are low in susceptibility have a high level of compliance and self-concept.

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Detection of Point Mutations in the rpoB Gene Related to Drug Susceptibility in Mycobacterium Tuberculosis using an Oligonucleotide Chip (올리고뉴클레오티드 칩(Oligonucleotide Chip)을 이용한 항결핵제 감수성과 관련된 Mycobacterium tuberculosis rpoB 유전자의 점돌연변이 판별 방법)

  • Kim, Hyun-Jung;Kim, Seong-Keun;Shim, Tae-Sun;Park, Yong-Doo;Park, Mi-Sun
    • Tuberculosis and Respiratory Diseases
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    • v.50 no.1
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    • pp.29-41
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    • 2001
  • Background : The appearance of multiple-drug-resistant Mycobacterium tuberculosis strains has been seriously compromising successful control of tuberculosis. Rifampin-resistance, caused by mutations in the rpoB gene, can be indicative of multiple-drug-resistance, and its detection is of great importance. The present study aimed to develop an oligonucleotide chip for accurate and convenient screening of drug-resistance. Methods : In order to detect point mutations in the rpoB gene, an oligonucleotide chip was prepared by immobilizing specific probe DNA to a microscopic slide glass by a chemical reaction. The probe DNA that was selected from the 81 bp core region of the rpoB gene was designed to have mutation sites at the center. A total of 17 mutant probes related to rifampin-resistance including 8 rifabutin-sensitive mutant probes were used in this study. For accurate determination, wild type probes were prepared for each mutation position with an equal length, which enabled a direct comparison of the hybridization intensities between the mutant and wild type. Results : Mycobacterial genomic DNA from clinical samples was tested with the oligonucleotide chip and the results were compared with those of the drug-susceptibility test in addition to sequencing and INNO-LiPA Rif. TB kit test in some cases. Out of 15 samples, the oligonucleotide chip results of 13 samples showed good agreement with the rifabutin-sensitivity results. The two samples with conflicting result also showed a discrepancy between the other tests, suggesting such possibilities as existence of mixed strains and difference in drug-sensitivity. Further verification of these samples in addition to more case studies are required before the final evaluation of the oligonucleotide chip can be made. Conlcusion : An oligonucleotide chip was developed for the detection of rpoB gene mutations related to drugsusceptibility. The results to date show the potential for using the oligonucleotide chip for accurate and convenient screening of drug-resistance to provide useful information in antituberculosis drug therapy.

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Effects of Body Weight and Dietary Protein Level on Ammonia Excretion by the Nile tilapia Oreochromis niloticus (나일틸라피아의 암모니아 배설에 미치는 어체중과 사료 내 단백질 함량의 영향)

  • Oh, Sung-Yong;Jo, Jae-Yoon
    • Journal of Aquaculture
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    • v.18 no.2
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    • pp.122-129
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    • 2005
  • Ammonia is the major limiting factor in intensive aquaculture production systems. Therefore, quantification of ammonia excretion is important for the water quality management in aquaculture systems. Ammonia excretion is known to be affected by many factors such as body weight and dietary protein level (DPL). In this study, experiments were carried out to investigate the effects of body weight and DPLs on the rates of ammonia excretion of Nile tilapia Oreochromis niloticus. Three sizes of fishes (mean initial weight; 4.8 g,42.7 g and 176.8 g) were fed each of two dietary protein levels (30.5% and 35.5%). Daily feeding levels for the three fish sizes of 4.8 g, 42.7 g and 176.8 g were 6%, 3%, and 1.5% body weight per day, respectively. Each group of fish was stocked in a 17.1-L aquarium and all treatments were triplicated. Following feeding, the weight-specific ammonia excretion rate of O. niloticus increased, peaked at 4 to 8 h, and returned to pre-feeding levels within 24 h. Total ammonia nitrogen (TAN) excretion.ate per unit weight decreased with the increase of fish weight for each diet (P<0.05). The TAN excretion rate increased with increasing dietary protein content for each fish size (P<0.05). TAN excretion rates (Y) for each diet with different fish weights were described by the following equations: low DPL diet (30.5%): $Y\;(mg\;kg^{-1}\;d^{-1})=955.69-147.12\;lnX\;(r^2=0.95)$, high DPL diet (35.5%): $Y\;(mg\;kg^{-1}\;d^{-1})=1362.41-209.79\;lnX\;(r^2=0.99)$. Where: X=body weight (g wet wt.). The TAN excretion rates ranged 28.5%-37.1% of the total nitrogen ingested for the low DPL diet (30.5%) and 37.4-38.5% for the high DPL diet (35.5%). Total nitrogen losses of fish fed the high DPL diet $(35.5%;\;0.26\sim0.91g\;kg^{-1}\;d^{-1})$ were higher than those fed the low DPL diet $(30.5%;\;0.22\sim0.68g\;kg^{-1}\;d^{-1})$. The losses decreased per kg of fish as fish size increased. Results will provide valuable information fer water quality management and culture of Nile tilapia in recirculating aquaculture systems.

Deviations of Implant Position between Pre- and Post-operation in Computer-guided Template-based Implant Placement (Computer-guided template를 이용한 임플란트 식립에서 술 전과 술 후 사이의 임플란트 위치에 따른 변위량 검사)

  • Kim, Won;Kim, Seung-Mi;Kim, Hyo-Jung;Song, Eun-Young;Lee, Si-Ho;Oh, Nam-Sik
    • Journal of Dental Rehabilitation and Applied Science
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    • v.27 no.2
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    • pp.175-184
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    • 2011
  • With a development of implant restoration technique, there are increasing use of computer-guided system for edentulous patients. It was carried out simulated operation based on CT information about patient's bone quantity, quality and anatomical landmark. However, there are some difference between the programmed implant and post-operative implant about it's position. If the deviation was severe, it could happen a failure of 'passive fit' and not suited for path of implant restoration. The aim of this presentation is to evaluate about a degree of deviations between programmed implant and post-operative implant. Five patients treated by 'NobelGuide' system (Nobel Biocare AB, G$\ddot{o}$teborg, Sweden) in Department of Prosthodontics, Inha University were included in this study. The patients were performed CT radiograph taking and intra-oral impression taking at pre-operation. Based on CT images and study model, surgical stent was produced by NobelBiocareTM. To fabricated a pre-operative study model, after connected lab analog to surgical template, accomplished a pre-operative model using type 4 dental stone. At final impression, a post-operative study model was fabricated in the conventional procedures. Each study model was performed CT radiograph taking. Based on CT images, each implant was simulated in three dimensional position using $Procera^{(R)}$ software (Procera Software Clinical Design Premium, version 1.5; Nobel Biocare AB). In 3D simulated model, length and angulation between each implant of both pre- and post-operative implants were measured and recorded about linear and angular deviation between pre-and post-operative implants. A total of 24 implants were included in this study and 58 inter-implant sites between each implant were measured about linear and angular deviations. In the linear deviation a mean deviation of 0.41 mm (range 0~1.7 mm) was reported. In the angular deviation, a mean deviation was $1.99^{\circ}$ (range $0^{\circ}{\sim}6.7^{\circ}$). It appears that the both linear and angular mean deviation value were well acceptable to application of computer-guided implant system.

A Study on the Seasonal Color Characteristics of Warm- and Cool-Season Grasses II. Color Characteristics and Life-span of Leaves in Turfgrasses and Cover Plants+ (난지형 및 한지형 지피식물의 엽색변화에 관한 연구 II. 엽색특성 및 엽수명연장)

  • 심재성;민병훈;서병기
    • Asian Journal of Turfgrass Science
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    • v.9 no.4
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    • pp.293-316
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    • 1995
  • Nitrogen fertilization and cutting practice were studied on turfgrasses and cover plants to investigate the possibility of maintaining green color during the growing season. Research also involved the effect of the nitrogen on a few morphological characteristics of leaf performance elements which might give an information to coloration and life-span of turf leaves. Treatments in the first experiment undertaken on pot included one N level: 350kgN /ha applied as compound fertilizer in split applications of one-half in mid-May and the rest both in late June and August, and four spring-summer cuts: late May, late June, late July and late August. The soil filled in pot a moderately well-drained sandy loam. In the second experiment(field observation) leaf length and width, inflorescence and flowering, and color performance were also investigated. With nitrogen fertilizer applied on turfs, desirable turf color was maintained during a period of poor coloration in specific seasons such as mid-summer for cool season grasses and late fall for warm season grasses comparing to the non-treatment. However, this was not stimulated by cutting treatment to nitrogen status existed. Cutting effect on coloration was more remarkable in both Korean lawngrass and Manilagrass than in cool season turfgrasses such as Italian rye-grass, perennial ryegrass and tall fescue. Especially down-slide of leaf color in cool season turfgrasses could he detected in mid-summer /early fall season ranging up to mid-September. In early November as well as mid-September, Italian ryegrass, perennial ryegrass and tall fes-cue retained a high level of green color as followed by nitrogen application and cutting treatment, and little detectable variation of leaf color notation between cool season turfgrasses was obtained. However, Korean la'vngrass and Manilagrass failed to retain the green color until early November. Color notations in cool season turfgrasses investigated early November on the final date of the experiment ranged from 5 GY 3/1 to 4/8 in 'Ramultra' Italian ryegrass, 'Reveile' perennial ryegrass and 'Arid' tall fescue, but those in Zoysiagrasses were 7.5 YR 4/8 in Korean lawngrass and 2.5 y 5 /6 in Manilagrass. Life-span of leaves was shorter in Italian ryegrass, perennial ryegrass and tall fescue than in beth Korean lawngrass and Manilagrass with and without nitrogen application. In general, leaves appeared in early May had a long life-span than those appeared in late April or mid-June. Nitrogen application significantly prolonged the green color retaining period in perennial ryegrass, Italian ryegrass, Korean lawngrass and Manilagrass, and this was contrasted with the fact that there was no prolonged life-span of leaves emerging in early May and mid-June in tall fescue. SPAD reading values in 48 turfs and cover plants investigated in the field trial were increasing until late June and again decreasing till September. Increasing trends of reading value could be observed in the middle of October in most of grasses. On the other hand, clovers and reed canarygrasses did not restore their color values even in October. Color differences between inter-varieties, and inter-species occurred during the growing season under the field condition implicated that selection of species and /or cultivars for mixture should be taken into consideration. In Munsell color notation investigated in the final date in the middle of November, 32 cultivars belonged under the category of 5 GY and 10 cultivars under the category of 7.5 GY. This was implying that most of cool season turfs and cover plants grown in the center zone of Korean Peninsula which are able to utilize for landscape use can bear their reasonable green color by early or mid-November when properly managed. The applicable possibilities of SPAD readings and Munsell color notation to determine the color status of turfgrasses and cover plants used in this study were discussed.

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Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2012 (설비공학 분야의 최근 연구 동향 : 2012년 학회지 논문에 대한 종합적 고찰)

  • Han, Hwataik;Lee, Dae-Young;Kim, Sa Ryang;Kim, Hyun-Jung;Choi, Jong Min;Park, Jun-Seok;Kim, Sumin
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.25 no.6
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    • pp.346-361
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    • 2013
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2012. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. The conclusions are as follows : (1) The research works on thermal and fluid engineering have been reviewed as groups of fluid machinery, pipes and valves, fuel cells and power plants, ground-coupled heat pumps, and general heat and mass transfer systems. Research issues are mainly focused on new and renewable energy systems, such as fuel cells, ocean thermal energy conversion power plants, and ground-coupled heat pump systems. (2) Research works on the heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer, and industrial heat exchangers. Researches on heat transfer characteristics included the results for natural convection in a square enclosure with two hot circular cylinders, non-uniform grooved tube considering tube expansion, single-tube annular baffle system, broadcasting LED light with ion wind generator, mechanical property and microstructure of SA213 P92 boiler pipe steel, and flat plate using multiple tripping wires. In the area of pool boiling and condensing heat transfer, researches on the design of a micro-channel heat exchanger for a heat pump, numerical simulation of a heat pump evaporator considering the pressure drop in the distributor and capillary tubes, critical heat flux on a thermoexcel-E enhanced surface, and the performance of a fin-and-tube condenser with non-uniform air distribution and different tube types were actively carried out. In the area of industrial heat exchangers, researches on a plate heat exchanger type dehumidifier, fin-tube heat exchanger, an electric circuit transient analogy model in a vertical closed loop ground heat exchanger, heat transfer characteristics of a double skin window for plant factory, a regenerative heat exchanger depending on its porous structure, and various types of plate heat exchangers were performed. (3) In the field of refrigeration, various studies were executed to improve refrigeration system performance, and to evaluate the applicability of alternative refrigerants and new components. Various topics were presented in the area of refrigeration cycle. Research issues mainly focused on the enhancement of the system performance. In the alternative refrigerant area, studies on CO2, R32/R152a mixture, and R1234yf were performed. Studies on the design and performance analysis of various compressors and evaporator were executed. (4) In building mechanical system research fields, twenty-nine studies were conducted to achieve effective design of mechanical systems, and also to maximize the energy efficiency of buildings. The topics of the studies included heating and cooling, HVAC system, ventilation, renewable energy systems, and lighting systems in buildings. New designs and performance tests using numerical methods and experiments provide useful information and key data, which can improve the energy efficiency of buildings. (5) In the fields of the architectural environment, studies for various purposes, such as indoor environment, building energy, and renewable energy were performed. In particular, building energy-related researches and renewable energy systems have been mainly studied, reflecting interests in global climate change, and efforts to reduce building energy consumption by government and architectural specialists. In addition, many researches have been conducted regarding indoor environments.