• 제목/요약/키워드: Data Reduction Technique

검색결과 497건 처리시간 0.033초

한국(韓國)에 있어서의 장내기생충감염(腸內寄生虫感染)의 현황(現況)과 추이(推移) (Current Status and Transition of the Prevalence of Intestinal Parasitic Infections in Korea)

  • 김동찬
    • 농촌의학ㆍ지역보건
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    • 제9권1호
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    • pp.83-108
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    • 1984
  • Out of a total of 58 species of helminthic and protozoan parasitic infections in Korea, so far 38 species were reported as intestinal parasites of man. Quite a few species of the intestinal parasitic infections have long been prevalent throughout the country and this has been a significant public health problem. In this paper, current status and transition of the intestinal parasitic infections in the past years were presented. Chronological reviewing of data show background and prospects of change in the prevalence of infections. In the national prevalence survey on parasitic infections conducted once every five years since 1971, stool examinations were done by both cellophane thick smear and brine flotation techniques. Every egg positive case of Ascaris lumbricoides and Clonorchis sinensis was further examined by Stoll's dilution egg counting technique. In 1981, perianal swab using adhesive cellulose tape was added for Enterobius infection. For protozoan cyst examination conducted by province and city in '81, fecal specimens were fixed in SAF solution and examined by the formalin-ether concentration technique. High prevalence of parasitic infection in ana before the 1960s can be easily understood from the data given by the Ministry of Health and Social Affairs in 1967. From a parasite control point of view, the 1960s was the preparatory period particularly for control of soil-transmitted helminthiasis. Several organizations which have contributed to parasite control were founded in this period and the prevention law of parasitic infections was passed in '66. In the '70s, overall prevalence rates of the common intestinal parasitic infections, which were highly prevalent in the past were turned into reduction phase for the first time. The '80s can be said to be an active control period of parasitic infections. Intestinal helminths According to the reports of the national prevalence survey on parasitic infections, the prevalence of helminthic infections was 84.3%(number of person examined:24,887) in '71, 63.2%(27,178) in '76, and 41.1%(35,018) in '81. By area, the prevalence rate in '81 was 35.1%(20,569) in urban areas and 49.6%(14,447) in rural areas. Intestinal nematodes Ascaris lumbricoides The prevalence of Ascaris infection has decreased significantly in recent years. Among students, the prevalence was 55.4%, in '69 and decreased to 4.7% in '83. In the national prevalence surveys, the prevalence decreased to 13.0% in '81 from 54.9% in '71. By area, the prevalence decreased to 8.5% in '81 from 46.4% in '71 in urban area and 19.4% in '81 from 59.6% in '71 in rural area. By age, the prevalence has become in recent years relatively even in all age groups, although higher prevalence used to be seen in young age groups of around 10 years old, particulary in the highly prevalent rural areas. By sex, the prevalence was higher in the female than in the male. Unfertilized egg positive rates among the ascariasis cases increased gradually up to 55.4% on the average in '81. The intensity of the infection was also significantly decreased. Trichuris trichiura Trichuris infection had also decreased to 23.4% in '81 from 65.4% in '71. By area, the decreasing tendency of the prevalence became faster in urban areas than in the rural areas. The prevalence in urban and rural areas in '71 was 69.7%, and 63.1% respectively and decreased to 19.5% and 29.0% respectively in '81. By age, the prevalence reached a peak at the 10-14 age group and showed relatively even distribution throughout all age groups. By sex, the prevalence was close in young age groups, but in the 30s or over age group, especially in rural area, the prevalence was significantly higher in the female than in the male. The prevalence has much fluctuated depending in the area. The prevalence in rural areas surveyed in the '80s shows a range between 20.9% and 73.7% by locality. It is anticipated that the prevalence of Trichuris infection will drop more rapidly, when mass treatment is conducted. Hookworms Hookworm infection by mostly Ancylostoma duodenale and a few by Necator americanus has decreased to a negligible levels in recent years. In the national prevalence surveys, the prevalence was 10.7% in '71, 2.2% in '76, and 0.5% in '81. The prevalence was higher in rural areas than in urban areas. Wide application of multi-specific anthelminthics in the ascariasis control programmes conducted in the past decade appear to have been effective against hookworm infection. Trichostrongylus orientalis As in the case with hookworm infection, the prevalence of Trichostrongylus infection has reached a negligible levels. In the national prevalence surveys, the prevalence was 7.7% in '71, 1.0% in '76 and 0.2% in '81. Enterobius vermicularis In the national prevalence survey in '81, the egg positive rate was 12.0%. Higher prevalence is expected when examined repeatedly. The prevalence rate was 10.3% in urban area and 14.6% in rural area. In recent surveys conducted in rural areas among schoolchildren, the prevalence was 32.4% in Gimhae Gun in '82 and 64.1% in Yeongyang Gun in '83. By age, the egg positive rate was higher in young age groups of around 10 and sharply decreased in age groups of around 20 and then somewhat increased again in middle age groups. By sex, the prevalence was higher in the female than in the male. Strongyloides stercoralis Strongyloides stercoralis infection has rarely been found in Korea. Three cases were reported in 1914. And 0.1-0.5% were found infected out of 2,642 persons examined at the prisoner-of-war camp on Geojedo in 1956. One case was reported in '54 and '82, respectively. Anisakis spp. No systematic survey has been conducted for anisakiasis In Korea. So far, only several cases have been found 1 case in Seoul in '71, 5 cases in Busan in '81 and 1 case in Busan in '84. Intestinal trematodes Metagonimus yokogawai In the national prevalence survey conducted in 1981, the egg positive rate was 1.24% on the average. High endemic areas are located in the southwestern part of Korea. The prevalence in Hadong Gun was 29.1% on the average in '79. In a survey conducted in 76, the prevalence was 44.0% in Gwangyang, 55.0% in Gogseung and 29.0% in Gurye. The infection is closely correlated with raw sweetfish consumption in these areas. Other intestinal trematodes A human case of Heterophyes heterophyes was reported in 1914. Several species were reported in the '80s : 17 cases of Fibricola seoulensis, 9 cases of Pygidiopsis summa, 8 cases of Heterophyes heterophyes nocens, 1case of Heterophyopsis continua, 2 cases of Stellantchasmus falcatus, 1 case of Stictodora sp., 1 case of Echinostoma hortense, and 4 cases of Echinochasmus japonicus. As the intermediate hosts, snakes and frogs play a role for F.seoulensis and fish for the rest of the species. Intestinal cestodes Taenia saginata and T. solium Egg positive rates in the national prevalence survey were 0.7% in '76 and 1.1% in '81. The prevalence in '81 was 0.6% in urban area and 1.8% in rural area. The proglottid positive rate in Jeju Do was 19.2% on the average. On Udo, Jeju Do in 1983, the egg positive rate among the inhabitants was 2.9%. Hymenolepis nana In the national prevalence survey, egg positive rates were 0.6% in '76 and 0.4% in '81. No difference was seen in the prevalence by area and sex. Hymenolepis diminuta Infected cases were reported : 3 in '64 and I in '66. Egg positive rate in '81 was 0.01% in the national prevalence survey. Diphylobothrium latum So far, about 30 cases have been reported. The cases have been reported more frequently in recent surveys. Mesocestoides sp. A case was reported from a hospitalized patient in Seoul in '67. Spirometra erinacei Two cases were reported in '84 following reidentification of the adult worms collected in '74. Intestinal protozoa Out of a total of 23 species of human protozoan infections in Korea, 13 species were reported as intestinal protozoa : Entamoeba histolytica, E coli, Endolimax nana, Iodamoeba b$\ddot{u}$tschlii, Dientamoeba fragilis, Giardia lamblia, Chilomastix mesnilii, Embadomonas sp., Enteromonas hominis, Trichomonas hominis, Isospora belli, I. Hominis(Sarcocystis hominis), and Balantidium coli. Since the first report on intestinal protozoan infections in 1925, there have been quite a few survey data on the prevalence of the infection. It was found reviewing the data chronologically that up to the early '70s the infection was prevalent around a 30-50%. After that, the protozoan cyst positive rate has shown the tendency of gradual decrease throughout the country. Protozoan cyst survey conducted in Seoul and several provinces in 1981 revealed infection rates of 8.9%(1,310) in Gangweondo, 10.7%(1,703) in Gyenggi Do, 11.7%(1,032) in Jeonra Buk Do, 9.1%(4,116) in Jeonra Nam Do, and 1.4%(5,275) in Seoul. Entamoeba histolytica In the survey conducted by province in '81, the cyst positive rate was 0.8% in Gangweon-do, 0.3% in Gyeonggi Do, 1.4% in both Jeonra Buk Do and Jeonra Nam Do, and 0.2% in Seoul. Giardia lamblia In the survey by province in '81, cyst positive rates were 2.2% in both Gyeonggi Do and Jeonra Buk Do, 1.9% in Jeonra Nam Do, 0.5% in Gangweon Do, and 0.9% in Seoul. Balantidium coli Two cases were reported. One in 1930 and the other in '74. Isospora belli and I. Hominis(Sarcocystis hominis) Isospora belli was reported : 1 case in '56 and 3 cases in '66. I. Hominis, recently identified to be synonymous with Sarcocystis hominis, was reported : 3 cases in '66. Other intestinal protozoa The protozoan parasites other than the above mentioned are generally treated as commensal, although some of them are considered to be pathogenic. The data of '81 show that about 10% of the inhabitants are still infected with protozoa.

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계획된 간호 정보가 수면량에 미치는 영향에 관한 연구 -개심술 환자를 중심으로- (The Effect of Structured Information on the Sleep Amount of Patients Undergoing Open Heart Surgery)

  • 이소우
    • 대한간호학회지
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    • 제12권2호
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    • pp.1-26
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    • 1982
  • The main purpose of this study was to test the effect of the structured information on the sleep amount of the patients undergoing open heart surgery. This study has specifically addressed to the Following two basic research questions: (1) Would the structed in formation influence in the reduction of sleep disturbance related to anxiety and Physical stress before and after the operation? and (2) that would be the effects of the structured information on the level of preoperative state anxiety, the hormonal change, and the degree of behavioral change in the patients undergoing an open heart surgery? A Quasi-experimental research was designed to answer these questions with one experimental group and one control group. Subjects in both groups were matched as closely as possible to avoid the effect of the differences inherent to the group characteristics, Baseline data were also. collected on both groups for 7 days prior to the experiment and found that subjects in both groups had comparable sleep patterns, trait anxiety, hormonal levels and behavioral level. A structured information as an experimental input was given to the subjects in the experimental group only. Data were collected and compared between the experimental group and the control group on the sleep amount of the consecutive pre and post operative days, on preoperative state anxiety level, and on hormonal and behavioral changes. To test the effectiveness of the structured information, two main hypotheses and three sub-hypotheses were formulated as follows; Main hypothesis 1: Experimental group which received structured information will have more sleep amount than control group without structured information in the night before the open heart surgery. Main hypothesis 2: Experimental group with structured information will have more sleep, amount than control group without structured information during the week following the open heart surgery Sub-hypothesis 1: Experimental group with structured information will be lower in the level of State anxiety than control group without structured information in the night before the open heart surgery. Sub-hypothesis 2 : Experimental group with structured information will have lower hormonal level than control group without stuctured information on the 5th day after the open heart surgery Sub-hypothesis 3: Experimental group with structured information will be lower in the behavioral change level than control group without structured information during the week after the open heart surgery. The research was conducted in a national university hospital in Seoul, Korea. The 53 Subjects who participated in the study were systematically divided into experimental group and control group which was decided by random sampling method. Among 53 subjects, 26 were placed in the experimental group and 27 in the control group. Instruments; (1) Structed information: Structured information as an independent variable was constructed by the researcher on the basis of Roy's adaptation model consisting of physiologic needs, self-concept, role function and interdependence needs as related to the sleep and of operational procedures. (2) Sleep amount measure: Sleep amount as main dependent variable was measured by trained nurses through observation on the basis of the established criteria, such as closed or open eyes, regular or irregular respiration, body movement, posture, responses to the light and question, facial expressions and self report after sleep. (3) State anxiety measure: State Anxiety as a sub-dependent variable was measured by Spi-elberger's STAI Anxiety scale, (4) Hormornal change measure: Hormone as a sub-dependent variable was measured by the cortisol level in plasma. (5) Behavior change measure: Behavior as a sub-dependent variable was measured by the Behavior and Mood Rating Scale by Wyatt. The data were collected over a period of four months, from June to October 1981, after the pretest period of two months. For the analysis of the data and test for the hypotheses, the t-test with mean differences and analysis of covariance was used. The result of the test for instruments show as follows: (1) STAI measurement for trait and state anxiety as analyzed by Cronbachs alpha coefficient analysis for item analysis and reliability showed the reliability level at r= .90 r= .91 respectively. (2) Behavior and Mood Rating Scale measurement was analyzed by means of Principal Component Analysis technique. Seven factors retained were anger, anxiety, hyperactivity, depression, bizarre behavior, suspicious behavior and emotional withdrawal. Cumulative percentage of each factor was 71.3%. The result of the test for hypotheses show as follows; (1) Main hypothesis, was not supported. The experimental group has 282 minutes of sleep as compared to the 255 minutes of sleep by the control group. Thus the sleep amount was higher in experimental group than in control group, however, the difference was not statistically significant at .05 level. (2) Main hypothesis 2 was not supported. The mean sleep amount of the experimental group and control group were 297 minutes and 278 minutes respectively Therefore, the experimental group had more sleep amount as compared to the control group, however, the difference was not statistically significant at .05 level. Thus, the main hypothesis 2 was not supported. (3) Sub-hypothesis 1 was not supported. The mean state anxiety of the experimental group and control group were 42.3, 43.9 in scores. Thus, the experimental group had slightly lower state anxiety level than control group, howe-ver, the difference was not statistically significant at .05 level. (4) Sub-hypothesis 2 was not supported. . The mean hormonal level of the experimental group and control group were 338 ㎍ and 440 ㎍ respectively. Thus, the experimental group showed decreased hormonal level than the control group, however, the difference was not statistically significant at .05 level. (5) Sub-hypothesis 3 was supported. The mean behavioral level of the experimental group and control group were 29.60 and 32.00 respectively in score. Thus, the experimental group showed lower behavioral change level than the control group. The difference was statistically significant at .05 level. In summary, the structured information did not influence the sleep amount, state anxiety or hormonal level of the subjects undergoing an open heart surgery at a statistically significant level, however, it showed a definite trends in their relationships, not least to mention its significant effect shown on behavioral change level. It can further be speculated that a great degree of individual differences in the variables such as sleep amount, state anxiety and fluctuation in hormonal level may partly be responsible for the statistical insensitivity to the experimentation.

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에디 공분산 기반의 플럭스 타워 관측자료를 이용한 국내외 산림과 농업 생태계 탄소 흡수량 분석 (Estimating carbon uptake in forest and agricultural ecosystems of Korea and other countries using eddy covariance flux data)

  • 이보라;강완모;김충기;김지은;이창훈
    • 환경영향평가
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    • 제26권2호
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    • pp.127-139
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    • 2017
  • 탄소 흡수원 조성과 같은 토지이용과 관련한 온실가스 감축대안 수립을 위해 다양한 생태계 시스템에서의 온실가스 잠재 흡수량 평가가 요구된다. 이 연구에서는 에디 공분산 기반의 플럭스 타워 관측자료를 활용한 순생태계교환량(Net Ecosystem Exchange: NEE)으로 국내 산림 생태계와 농경지 생태계에서의 탄소 흡수 능력을 추정하였다. 또한 우리나라와 유사한 기후조건의 국외 플럭스 타워 자료를 활용하여 국내 생태계 유형별 탄소 수지 추정결과와 비교분석하였다. 에디 공분산 기법을 이용한 산림과 농경지의 NEE 분석 결과, 우리나라의 산림에서는 연간 $-31gC/m^2/yr$에서 $-362gC/m^2/yr$, 농경지 생태계에서는 작물 재배 기간 동안 $-210gC/m^2/growing$ season에서 $-248gC/m^2/growing$ season의 값을 나타내 산림뿐만 아니라 농경지 생태계도 탄소 흡수 기능이 있음을 확인할 수 있었다. 산림의 경우 임상에 따라 시기별로 서로 다른 탄소 흡수 양상을 보였는데, 활엽수림은 늦봄과 초여름, 초가을에, 침엽수림은 봄과 초여름, 가을중순에 탄소 흡수 능력이 컸다. 또한 숲의 나이가 어리고, 활엽수나 침엽수로만 구성된 단순림보다 혼효림이 더 높은 탄소 흡수 능력을 가지고 있었다. 농작물의 성장기간 동안의 탄소 흡수량은 비트가 가장 컸고, 그 다음은 겨울밀, 옥수수, 벼, 감자, 콩 순으로 나타났다. 이러한 결과들은 향후 산림 및 농경지에서의 탄소저감 정책수립과정에 있어 유용한 기초자료로 활용될 수 있을 것이다.

독립신호 교차로에서의 교통안전을 위한 서비스수준 결정방법의 개발 (DEVELOPMENT OF SAFETY-BASED LEVEL-OF-SERVICE CRITERIA FOR ISOLATED SIGNALIZED INTERSECTIONS)

  • Dr. Tae-Jun Ha
    • 대한교통학회:학술대회논문집
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    • 대한교통학회 1995년도 제27회 학술발표회
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    • pp.3-32
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    • 1995
  • The Highway Capacity Manual specifies procedures for evaluating intersection performance in terms of delay per vehicle. What is lacking in the current methodology is a comparable quantitative procedure for ass~ssing the safety-based level of service provided to motorists. The objective of the research described herein was to develop a computational procedure for evaluating the safety-based level of service of signalized intersections based on the relative hazard of alternative intersection designs and signal timing plans. Conflict opportunity models were developed for those crossing, diverging, and stopping maneuvers which are associated with left-turn and rear-end accidents. Safety¬based level-of-service criteria were then developed based on the distribution of conflict opportunities computed from the developed models. A case study evaluation of the level of service analysis methodology revealed that the developed safety-based criteria were not as sensitive to changes in prevailing traffic, roadway, and signal timing conditions as the traditional delay-based measure. However, the methodology did permit a quantitative assessment of the trade-off between delay reduction and safety improvement. The Highway Capacity Manual (HCM) specifies procedures for evaluating intersection performance in terms of a wide variety of prevailing conditions such as traffic composition, intersection geometry, traffic volumes, and signal timing (1). At the present time, however, performance is only measured in terms of delay per vehicle. This is a parameter which is widely accepted as a meaningful and useful indicator of the efficiency with which an intersection is serving traffic needs. What is lacking in the current methodology is a comparable quantitative procedure for assessing the safety-based level of service provided to motorists. For example, it is well¬known that the change from permissive to protected left-turn phasing can reduce left-turn accident frequency. However, the HCM only permits a quantitative assessment of the impact of this alternative phasing arrangement on vehicle delay. It is left to the engineer or planner to subjectively judge the level of safety benefits, and to evaluate the trade-off between the efficiency and safety consequences of the alternative phasing plans. Numerous examples of other geometric design and signal timing improvements could also be given. At present, the principal methods available to the practitioner for evaluating the relative safety at signalized intersections are: a) the application of engineering judgement, b) accident analyses, and c) traffic conflicts analysis. Reliance on engineering judgement has obvious limitations, especially when placed in the context of the elaborate HCM procedures for calculating delay. Accident analyses generally require some type of before-after comparison, either for the case study intersection or for a large set of similar intersections. In e.ither situation, there are problems associated with compensating for regression-to-the-mean phenomena (2), as well as obtaining an adequate sample size. Research has also pointed to potential bias caused by the way in which exposure to accidents is measured (3, 4). Because of the problems associated with traditional accident analyses, some have promoted the use of tqe traffic conflicts technique (5). However, this procedure also has shortcomings in that it.requires extensive field data collection and trained observers to identify the different types of conflicts occurring in the field. The objective of the research described herein was to develop a computational procedure for evaluating the safety-based level of service of signalized intersections that would be compatible and consistent with that presently found in the HCM for evaluating efficiency-based level of service as measured by delay per vehicle (6). The intent was not to develop a new set of accident prediction models, but to design a methodology to quantitatively predict the relative hazard of alternative intersection designs and signal timing plans.

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한반도 지역에서의 상층중력장 (External Gravity Field in the Korean Peninsula Area)

  • 정애영;최광선;이영철;이정모
    • 자원환경지질
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    • 제48권6호
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    • pp.451-465
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    • 2015
  • 주변 해역을 포함한 한반도 일원에서 측정된 중력자료로부터 상층중력의 고도이상(free-air anomaly)을 계산하였다. 주변 영역에서는 인접국가가 발표한 중력자료가 있는 경우 발표된 자료를 이용하였으며, 없는 경우 EGM2008(Earth Gravitational Model 2008)로부터 계산한 고도이상을 이용하였다. 중력의 상향연속은 Dragomir가 제안한 방법으로 계산하였다. 상층중력 고도이상 계산의 정확성과 계산 속도를 고려하여 적분반경은 계산 고도의 10배로 하였다. 적분에 필요한 측지선의 거리는 Bowring이 개발한 공식을 사용하였다. 위도 $33^{\circ}N{\sim}43^{\circ}N$, 경도 $124^{\circ}E{\sim}131^{\circ}E$에서 계산된 고도이상은 고도 1 km에서 -41.315에서 189.327 mgal까지 변화하고 표준 편차는 22.612 mgal이다. 고도 3 km에서는 -36.478에서 156.209 mgal까지 변화하고 표준 편차는 20.641 mgal이다. 고도 1,000 km에서는 3.170에서 5.864 mgal까지 변화하고 표준 편차는 0.670 mgal이다. 3 km 고도에서 계산된 고도이상을 같은 높이에서 측정한 항공 중력 고도이상과 비교하였다. 이들의 rms 오차는 3.88 mgal로 나타났다. 항공 중력 측정 교차점오차가 2.2 mgal 임을 고려하면 이들 오차에 의미를 부여할 수 없으며, 원인으로는 이번 연구에서 발생한 계산상 오차와 함께/또는 발표된 항공중력의 보정오차에 기인하는 것으로 사료된다. 상층중력 고도이상에 완전식으로 계산한 지구타원체 외부의 정규중력을 더하여 상층중력을 예측하였다. 이번 연구에서 국내 최초로 계산한 고도에 따른 상층중력 고도이상은 한반도 일원의 상층중력장을 잘 표현하고 있는 것으로 보이며, 상층중력장은 관성항법장치의 정확도 향상 등에 이용될 수 있을 것이다.

동기면담을 적용한 구강 관리 프로그램의 효과 (The Effect of Oral Health Care Program Based on Motivational Interviewing)

  • 한예슬;배현숙;조영식
    • 치위생과학회지
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    • 제14권3호
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    • pp.287-294
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    • 2014
  • 본 연구는 구강 건강 개선을 위해 효과적인 구강 보건 교육방법을 모색하고자 동기면담이라는 새로운 상담기법을 적용한 구강 관리 프로그램을 진행하였다. 동기면담의 효과를 검증하고, 구강 관리 프로그램 개발의 기초자료로 제시하고자 대학생 98명을 대상으로 구강 관리 프로그램을 시행하였다. 첫 방문 날짜를 기준으로 실험군 32명과 대조군 66명으로 배정하였으며, 실험군에게는 총 3회의 동기면담을 시행한 결과 다음과 같은 결과를 얻었다. 1. 중재 유무에 따라 프로그램 참여 전후의 구강 상태를 비교한 결과 실험군에서 유의한 차이를 나타냈다. 치주상태를 평가하는 PSR, 치은 지수, 치석 지수, 치면세균막 지수, QLF-D 측정값인 SPS 모두 중재 전보다 중재 후에 측정값이 유의하게 감소하였다(p<0.05). 2. 구강 관리 프로그램 시행 기간 총 3회 동안 치면세균막지수값을 측정한 결과 두 집단 간의 차이는 통계적으로 유의하지 않았으나(p>0.05), 3회의 치면세균막 측정 시점 간의 차이는 통계적으로 유의하였으며 집단과 측정 시점간의 교호작용도 유의한 차이를 나타냈다(p<0.05). 3. 구강 관리 프로그램 참여 기간 동안 재방문 준수도는 실험군의 방문 준수도가 높게 나타났다. 또한 프로그램 재방문에 영향을 미치는 요인을 분석한 결과 동기면담을 시행한 집단이 시행하지 않은 집단보다 재방문할 가능성이 23.89배 높았으며, 구강 양치액을 사용하는 사람이 사용하지 않는 사람보다 21.73배, 치주상태 측정값 PSR이 큰사람이 12.19배 재방문할 가능성이 높은 것으로 나타났다(p<0.05). 이상의 결과를 종합해 보면, 동기면담의 시행은 구강 상태를 개선하며 그 가운데 치면세균막 감소에 높은 영향력이 있음을 확인할 수 있다. 또한 동기면담을 적용한 집단은 치면세균막 지수가 점차 감소하는 반면 중재를 시행하지 않는 집단은 다시 증가하는 양상을 나타내어 동기면담의 시행이 행동 유지에 관련이 있음을 알 수 있다. 동기면담 시행 집단이 재방문율이 높고, 재방문 준수에 동기면담의 영향력이 있는 것을 확인하였으므로 동기면담은 구강 관리 프로그램에 적용 가능하며 구강건강개선에 영향력 있는 중재로 이용될 것으로 생각된다.

시뮬레이션 모형에 의한 온실의 열환경 분석 (Analysis of Greenhouse Thermal Environment by Model Simulation)

  • 서원명;윤용철
    • 생물환경조절학회지
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    • 제5권2호
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    • pp.215-235
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    • 1996
  • 본 연구에서 수행한 Model 시뮬레이션에 의한 열환경 분석 기법은 지역별로 다양한 기상여건 하에서 대상온실의 난방 및 냉방부하를 보다 합리적으로 예측할 수 있을 뿐만 아니라 냉방이나 난방용 시스템의 결정을 비롯한 난방대책을 수립하고, 에너지 이용 전략의 수립이나 계절적인 작부계획 수립, 온실산업용 적지선정 등에 유익하게 활용될 수 있을 것이라 판단된다. 본 연구에서는 온실의 적극적인 환경조절 유형을 난방과 냉방의 두 가지로 대별하고, 난방 소요열량 산정을 비롯하여 야간의 보온 커튼효과, Heating Degree-Hour 산정 등 난방과 관련된 시뮬레이션은 동적 모형을 이용하여 시간별, 일별 및 월별로 검토하였으며, 환기를 비롯한 차광, 증발냉각시스템의 효과 분석은 정적모형을 이용하여 검토하였다. 특히 하절기 지하수와 같은 저온수를 직접 이용하거나 Heat Pump를 통하여 확보될 수 있는 저온수를 이용하여 온실의 피복면에 살수함으로서 확보할 수 있는 온실냉방효과를 검토하는 데는 1.2m$\times$2.4m 크기의 모형온실을 제작하여 기초실험을 수행함으로서 동절기의 수막시스템의 보온효과와 마찬가지로 하절기 냉방 효과를 거둘 수 있다는 가능성을 확인하였다. 본 연구에 활용된 온실의 수치 환경모형 중 난방관련 시뮬레이션용 동적 수치모형은 소기의 목적을 달성하는데 충분히 응용될 수 있는 이론모형이다. 이 이론모형이 범용성이 높은 것은 온실 내ㆍ외의 미기상 변화, 특히 난방이나 냉방이 본격적으로 요구되는 기간동안에 온도, 습도, 일사, 풍속 등의 미기상 인자들을 면밀하게 관찰하여 실측된 자료를 바탕으로 개발되었고, 다양한 자료에 의해 충분히 검정되었기 때문이다. 본 연구에서는 경남 진주지역의 어느 특정 기간(1987년)의 시간별 기상자료를 중심으로 온실의 열적 환경변화에 대한 수치모형 시뮬레이션을 실시하였으며, 아직 수치모형에 의한 시뮬레이션이 불가능한 일부 냉방효과를 검토하는 데는 모형 실험을 실시하였으며, 그 결과를 요약하면 다음과 같다. 1. 주간과 야간의 설정온도를 달리하고 다단계 변온조절방식으로 시뮬레이션을 행한 결과 난방 소요열량은 난방 설정온도에 따라 현저한 차이를 보였다. 특히 주간 설정온도에 비하여 야간 설정온도가 난방 소요열량에 예민하게 영향을 미치므로 야간의 설정온도 결정에 신중을 기해야 할 것으로 판단된다. 2. 기존의 Heating Degree-Hour 자료는 평균 외기온을 중심으로 임의의 설정온도에 대하여 산정된 값이므로 난방 소요열량에 대한 상대적인 비교수단은 되나 고려되는 기상인자의 제한과 설정온도의 임의성 때문에 실용성이 부족하다. 따라서 본 연구에서 제시된 것처럼 온실 주변의 제반 미기상 인자나 경계조건이 반영됨은 물론 작물의 생육상태 및 구체적인 설정온도까지도 고려하는 동적 수치모형으로 시시각각으로 예측된 실내기온을 중심으로 재배기간 동안의 난방열량을 적산함이 합리적이라 판단된다. 기존의 MDH 자료로 난방 설계를 할 경우에는 지나치게 과잉설계 될 가능성이 있다. 3. 산정된 난방 소요열량은 물론 커튼의 보온성능도 월별 기상여건에 따라 현저한 차이를 보이며, 시뮬레이션에 이용된 커튼의 경우 높은 보온효과를 보임으로서 년 평균 50% 이상의 난방 에너지를 절감할 수 있으며, 동절기 3-4개월의 집중 난방기에 에너지가 크게 절감됨을 발견할 수 있다. 4. 고온기 환기성능은 온실의 구조, 기상조건, 작물의 생육상태 등에 따라 다소의 차이가 있으나 환기율에 의해 크게 좌우되며, 시뮬레이션에 이용된 두 가지 농가보급형 온실 모두 환기율의 증가에 따른 실내기온의 강하 효과가 환기율이 1회/min 정도를 넘어서면서 급격히 둔화되는 현상을 보인다. 이는 기존에 권장되고 있는 적정 환기율인 1회/min 전후의 환기 시스템을 갖추는 것이 합리적임을 확인해 준다. 5. 작물이 성숙된 유리온실에서 외기의 상대습도가 50%인 쾌청한 주간동안 연속적으로 1회/min로 환기를 시킬 경우 실내기온 36.5$^{\circ}C$의 대조구에 비한 온도강하는 50% 차광만 했을 시 2.6$^{\circ}C$이고 효율 80%의 Pad & Fan 시스템만 작동시 6.1$^{\circ}C$ 정도이며, 차광과 냉각시스템을 동시에 작동시는 약 8.6$^{\circ}C$로서 외기온보다 3.3$^{\circ}C$가 낮은 28$^{\circ}C$까지 실내온도를 낮출 수 있으나, 동일 조건하에서 외기의 상대습도가 80%로 높은 경우에는 Pad & Fan시스템에 의한 온도강하가 2.4$^{\circ}C$에 불과하여 50% 차광하에서도 외기온 이하로 실내온도를 낮출 수 없음을 알 수 있다. 6. 하절기 3개월(6/1-8/31)동안 Pad & Fan 시스템의 냉방효과($\Delta$T)는 설정된 작동 온도에 따라 다소 차이를 보일 것으로 예상되나 본 시뮬레이션에서 설정한 시스템의 작동 온도 27$^{\circ}C$에서 상대습도와의 상관관계는 대략 다음과 같았다: $\Delta$T= -0.077RH+7.7 7. 전형적인 하절기 주간기상 하에서 경시적 냉방효과를 분석한 결과 환기만으로는 실내기온을 외기온 보다 5$^{\circ}C$ 높게 유지하는 정도가 고작이고, 차광이나 증발식 냉방시스템 만으로는 작물이 성숙한 단계에서조차도 외기온 이하로 떨어뜨리기가 어려우나 차광과 아울러 증발식 냉방을 병행할 경우에는 작물상태에 따라 다소 차이는 있지만 실내기온을 외기온보다 2.0-2.3$^{\circ}C$ 낮게 유지할 수 있음을 발견할 수 있다. 8. 일사가 차단된 27.5-28.5$^{\circ}C$의 외기온하에서 6.5-8.5$^{\circ}C$의 냉수를 온실 바닥면적 1$m^2$당 1.3 liter/min의 유량으로 온실표면에 살수했을 때 실내기온을 외기온보다 1$0^{\circ}C$ 낮은 16.5-18.$0^{\circ}C$ 정도로 낮출 수 있었다. 앞으로 살수 수온(T$_{w}$ )이나 외기온(T$_{o}$ ) 뿐만아니라 살수율(Q)에 따라 온실기온 (T$_{g}$ )에 미치는 상관 관계 T$_{g}$ = f(T$_{w}$ , Q, T$_{o}$ )를 구명하여 지하수 자체 또는 Heat Pump를 이용한 지하수온 이하의 냉수로 온실냉방의 가능성을 구명하는 것이 앞으로의 과제이다.

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