• Biomolecules & Therapeutics
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• v.3 no.1
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• pp.21-27
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• 1995

The only compounds with antagonistic activity via AT$_1$receptor, one of two subtypes of angiotensin II (AII) receptor, have been demonstrated to block the vasoconstriction effects of AII and thereby provide therapeutic potential. This initiated the search for compounds with high specific affinity to AT$_1$receptor and their effective screening methods. The radioligand binding assay for the AII receptor is regarded as the primary method for the evaluation of AT$_1$receptor antagonists for their activity. In this paper, we characterized the liver AT$_1$receptor and describe the efficient method of the radioligand binding assay using rat liver as a source of AT$_1$receptor. Equilibrium binding studies with rat adrenal cortex, adrenal medulla, liver and bovine adrenal showed that the specific bindings of [$^3$H] AII were saturable in all tissues and the Scatchard plots of those data were linear, suggesting a single population of binding sites. Hill slopes were very near to the unity in all tissues. Kinetic studies of [$^3$H) AII binding in rat liver homogenates yielded two association rate constants, 4.10$\times$10$^{7}$ M$^{-1}$ min$^{-1}$ and 4.02$\times$10$^{9}$ M$^{-1}$ min$^{-1}$ , with a single dissociation rate constant, 7.07$\times$10$^{-3}$ min-$^{-1}$ , possibly due to the partial dissociation phenomenon. The rank order of inhibition potencies of [$^3$H] AII binding in rat liver was AII>Sarile>Losartan>PD 123177. Rat liver homogenates revealed to have very high density of homogeneous population of the AT$_1$receptor subtype, as the specifically bound [$^3$H] AII was not inhibited by PD 123177, the nonpeptide antagonist of AT$_2$. The results of this study demonstrated that the liver homogenates from rats could be the best receptor preparation for the AT$_1$receptor binding assay and provide an efficient system for the screening of newly synthesized candidate compounds of AT$_1$receptor antagonist.

• 한국해양학회지
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• v.26 no.4
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• pp.313-323
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• 1991

Fine-grained sediments of the Han River and adjacent Kyonggi Bay have been studied using the powder x-ray diffractometer in order to study the distributional characteristics of clay minerals in the bottom and suspended sediments. The result of the XRD analyse shows that the major clay minerals in the lower Han River are composed of illite (57.1%), kaolinite (22.9%), and chlorite (19.6%) and that those of the Han River Estuary are composed of illite (67.2%), chlorite (16.5%), kaolinite 915.5%), and smectite (1.3%). The variation of mineral content shows distinct distributional characteristics depending on sedimentary environments. The illite content increases gradually approaching the Kyonggi Bay and kaolinite content decreases toward the sea within the range between 11% and 23%. The trend of chlorite is similar to that of kaolinite, the amount of which ranges between 14% and 19%. Smectite content is lower than 3%. Analysis of illite using peak-intensity ratio (001/002) indicates that two types of illites occur in the study area. Dioctahedral-type illite occurs as an indicator of the marine sediments. The illites distributed between the Kyonggi Bay and the Han River are mixtures of dioctahedral- and trioctahedral-types. This study indicates that the distribution of illite, kaolimite, and chlorite has been influenced mainly by the supply from the Han River and redistributed by estuarine circulation, such as tidal circulation and seasonal variation of river discharge. However, smectite is apparently supplied from other sources such as Yellow Sea or China. This study suggests that estuarine mixing system and seasonal variations of river discharge are the major factors controlling the distribution pattern of clay minerals in the study area.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.10
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• pp.192-199
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• 2000

The design of multi-stage gear drives is a time-consuming process because it includes more complicated problems, which are not considered in the design of single-stage gear drives. The designer has no determine the number of reduction stages and the gear ratios of each reduction stage. In addition, the design problems include not only dimensional design but also configuration design of gear drive elements. There is no definite rule or principle for these types of design problems. Thus the design practices largely depend on the sense and the experiences of the designer, and consequently result in undesirable design solution. A new and generalized design algorithm has been proposed to support the designer at the preliminary phase of the design of multi-stage gear drives. The proposed design algorithm automates the design process by integrating the dimensional design and the configuration design process. The algorithm consists of four steps. In the first step, the user determines the number of reduction stages. In the second step, gear ratios of every stage are chosen using the random search method. The values of the basic design parameters of a gear are chose in the third step by using the generate and test method. Then the values of the dimensions, such as pitch diameter, outer diameter and face width, are calculated for the configuration design in the next step. The strength and durability of each gear is guaranteed by the bending strength and the pitting resistance rating practices by using AGMA rating formulas. In the final step, the configuration design is carried out using simulated annealing algorithm. The positions of gears and shafts are determined to minimize the geometrical volume (size) of a gearbox while avoiding interferences between them. These steps are carried out iteratively until a desirable solution is acquired. The proposed design algorithm is applied to the preliminary design of four-stage gear drives in order to validate the availability. The design solution has considerably good results in both aspects of the dimensional and the configuration design.

• Journal of Preventive Medicine and Public Health
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• v.21 no.1 s.23
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• pp.195-206
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• 1988

Two major issues of the blood bank management are quality assurance and inventory control. Recently, in Korea blood donation has gained popularity increasingly to allow considerable improvement of the quality assurance with respect to blood collection, transportation, storage, component preparation skills and hematological tests. Nevertheless the inventory control, the other issue of blood bank management, has been neglected so far. For the supply of blood by donation barely meets the demand, the blood bank policy on the inventory control has been 'the more the better.' The shortage itself by no means unnecessitate inventory control. In fact, in spite of shortage, no small amount of blood is outdated. The efficient blood inventory control makes it possible to economize the blood usage in the practice of state-of-the-art medical care. For the efficient blood inventory control in Korean hospitals, this tudy is to develop formulae forecasting the standard blood inventory level and suggest a set of policies improving the blood inventory control. For this study informations of $A^+$ whole bloods and packed cells inventory control were collected from a University Hospital and the Central Blood Bank of the Korean Red Cross. Using this informations, 1,461 daily blood inventory records were formulated.48 varieties of blood inventory control environment were identified on the basis of selected combinations of 4 inventory control variables-crossmatch, transfusion, inhospital donation and age of bloods from external supply. In order to decide the optimal blood inventory level for each environment, simulation models were designed to calculate the measures of performance of each environment. After the decision of 48 optimal blood inventory levels, stepwise multiple regression analysis was started where the independent variables were 4 inventory control variables and the dependent variable was optimal inventory level of each environment. Finally the standard blood inventory level decision rule was developed using the backward elimination procedure to select the best regression equation. And the effective alternatives of the issuing policy and crossmatch release period were suggested according to the measures of performance under the condition of the standard blood inventory level. The results of this study' were as follows ; 1. The formulae to calculate the standard blood inventory level($S^*$)was $S^*=2.8617X(d)^{0.9342}$ where d is the mean daily crossmatch(demand) for a blood type. 2. The measures of performace - outdate rate, average period of storage, mean age of transfused bloods, and mean daily available inventory level - were improved after maintenance of the standard inventory level in comparison with the present system. 3. Issuing policy of First In-First Out(FIFO) decreased the outdate rate, while Last In-First Out(LIFO) decreased the mean age of transfused bloods. The decrease of the crossmatch release period reduced the outdate rate and the mean age of transfused bloods.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.2
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• pp.203-209
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• 1983

The occurrence and regional distribution of low temperature and drought during rice cropping period in Korea were studied to characterize the climatic impacts. The long term changes in rice yield, air temperature and precipitation were analyzed, and regional distributions were characterized. The significant climatic impacts on rice yield were heavy rain or flood, drought and low temperature. Since 1910, the occurrence of drought was 29 times, that of flood was 24 times and that of low temperature was 9 times; however, the drought and flood damages were decreased due to expansion of irrigation system since 1970 but low temperature damage was remarkedly increased. The long term changes in air temperature since 1908 in Suweon showed that the 5-year moving average from July to August decreased while that from May to June increased. The occurrence probability of the long term and early term low temperature types were the greatest in Korea and were in order of Suweon, Daegu and Kwangiu. The long term changes in 10-year moving average precipitation from April to June showed a 15 year cycle and recent years were in low precipitation period. The drought frequencies were the highest in Daegu and Pohang area. According to the precipitation from April to June and resevtoir storage at late June, the severest dry area were the Youngnam inland and the southwest coastal area.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.12
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• pp.4896-4906
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• 2010

This study was conducted in order to promote students' interest in overseas employment and to present methods of improving education that suits globalization and internalization. From responses to individual written survey questionnaires answered by $3^{rd}$grade 200 students who are studying dental hygiene at colleges in Daegu. They had most interested in Japan (60.3%), and they want to work abroad if they are given the changes (38.1%), which indicate that the dental hygiene majors have much interest and positive attitude in overseas employment. In Japan, there are 158 schools had department of dental hygiene (51 to 2 years, 101 to 3 years, 6 to 4 years). Especially, Kanto area has 25 private schools. When compared Korea and Japan, they similar were curriculum, 39 at 3 years, 44 at 4 years, respectively. The current national board dental hygiene examination system was 200 in total score, and 19 in total subjects. The 9 basic clinical courses including oral anatomy have 100 scores, and the 8 subjects including preclinical course have 50 scores, one dental assistant course have 50 scores. In Japan, 4 years pre-dental hygiene curriculum content provide certificate of dental hygiene after graduation. They provide additionally 'social worker' in Tokyo University, 'teacher in nursing' in Hirosima University. They scheduled the various foundational knowledge and skill such as competencies to communicate effectively, to participate community health program, and to make decisions regarding dental hygiene service.

• Korean Journal of Health Education and Promotion
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• v.6 no.1
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• pp.22-33
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• 1989

Rapid socio-cultural and economic changes in the country has brought with it changes in the society's value system. For a traditional society that is increasingly being exposed to modernization but where sex norms are still very restrictive, the adolescent sexual mores takes on added significance. Adolescents are caught between two opposing forces, the changing environment that allows for freer and liberal mores and the traditional society that cannot keep pace with the changing environment and therefore demands resistance to changes. This paper focuses on problems of adolescent sexuality in this country and considers the countermeasures for the existing problems. Amongst the problems are: (a) increasingly younger age of the adolescents who start sexual intercourse (b) non-use of contraception, (c) unwanted pregnancies, (d) increase in the number of induced abortion and (e) increase in the number of unwanted children and unmarried mothers. The Korean adolescent's sexual behavior seems to follow that of the developed countries. In other words, many western modes of life and sexual values seem to bave been copied in Korea and yet Korean adolescents lack in their knowledge of sex related matters such as reproductive physiology and contraception. Among middle and high school students, female students are reported to have less knowledge on sex than male students according to a 1988 survey by KIPH. Even among the unmarried famale factory workers, only 42.5 percent replied they know of the condom, and 25.1 percent and 23.1 percent said they had knowledge of spermicide and menstrual regulation respectively. However, 14.9 percent and 13.9 percent reported that they had a knowledge of the loop and female sterilization respectively according to the 1984 study by KIPH. Among the middle school students 0.8 percent said they had experience in sexual intercourse, while 7.3 percent of the high school students reported having had sexual intercourse. The sexual intercourse experience rate among the unmarried female factory workers is 37.8 percent. Among those female factory workers with sexual experience, 46.7 percent had more than one sex partners. Only 39.1 percent of male students and 18.9 percent of female students among those with sexual intercourse experience have used contraceptives. mostly condoms and oral pills 45.1 percent of female factory workers with sexual intercourse experience used contraceptives such as pills, condoms and rhythm methods. The pregnancy experience rate among the female factory workers who had experience in sexual intercourse is 29.5 percent, which is 11.1 percent among the total respondents. Out of the 102 pregnant female workers, 98 workers(96.1 percent) terminated their pregnancy by induced abortion and 2 workders(2 percent) in natural abortion, while 1 worker(1 percent) was in pregnancy and another 1 worker had normal birth that was subsequently sent to orphanage. In order to cope with the problem of adolescent sexuality, a drastic and strong policy measures should be taken by the government. The most effective countermeasure to the adolescent sexual problems appears to the education. The sex and population education in the school is very much in need. In addition, sex education program through mass media and at the job sit-should be promoted for a healthy development of adolescents' sexual behavior. Also, the existing national family planning program, which has focused on the married couples, should be extended to the unmarried people in its scope and contents of the program.

• Research in Community and Public Health Nursing
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• v.10 no.2
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• pp.275-290
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• 1999

The Objectives of this study were to identify family nursing phenomena at the community in Korea and to contribute to build up family domain of International Classification for Nursing Practice. The method of this study was used retrospective one among three methods to develop ICNP during the period from April 1997 to June 1999. The procedure was to choose nursing phenomena using preliminary terms(stepl) from the reports on family nursing care of the nursing students of 5 junior colleges of nursing and 5 colleges of nursing. The study group members identified 3 common family nursing phenomena with 5 characteristics related to each phenomenon. In order to consensus the appropriate characteristics of a phenomenon(step2), 17 study group members had regrouped nursing phenomena and scored its characteristics 5 times. The essential characteristics of each family phenomenon were selected above 3.5 mean score from related characteristics(step 3). Finally, 17 phenomena were named preferred terms such as following, that was selected after investigated preliminary terms(step4). Family nursing phenomena in Korea are named as Lack of family interaction in community. Social isolation. Lack of social support system in community. Disturbance in parent role, Disturbance in marital role, Dissatisfaction of sexual life, Disturbance in family communication, Inappropriate family coping, Lack of family intimacy, Inappropriate family power structure, Family violence. Unhealthy life style. Deficit of financial management skill and support. Inadequate care a sick member. Insecure safety and hygiene in neighborhood, Inadequate home-sanitation. Inadequate home-making. Family nursing phenomena in Korea were partially confirmed family architecture of ICNP, Beta version. by this study. Further study on Family nursing phenomena in Korea will be required to support evidence through literature review of nursing classifications or field studies.

• Journal of the Korean Institute of Gas
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• v.1 no.1
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• pp.106-112
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• 1997

This study measured the ignition limits of methane-air, propane-air, ethylene-air, and hydrogen-air mixture gases by discharge spark of D.C. power resistive circuit. The used experimental device is the IEC type spark ignition test apparatus, it consists of explosion chamber and supply -exhaust system of mixture gas. Mixture gases (methane-air, propane-air, ethylene-air, and hydrogen-air) were put into explosion chamber of IEC type spark ignition test apparatus, then it was confirmed whether ignition was made by 3,200 times of discharge spark between tungsten electrode and cadmium electrode. The ignition limits were found by increasing or decreasing the value of current. For the exact experiment, the ignition sensitivity was calibrated before and after the experiment in each condition. The ignition limits were found by changing the value of concentration of each gas-air mixture in D.C. 24 [V] resistive circuit. As the result of experiment, it was found that the minimum ignition limit currents exist at the value of methane-air 8.3 [$Vol\%$], propane-air 5.25[$Vol\%$], ethylene-air 7.8 [$Vol\%$], and hydrogen-air 21[$Vol\%$] mixture gases. For each the minimum ignition concentration of gases, the relationships between voltage and minimum ignition current were found. The results are as follows. - The minimum ignition limits are decreasing in the order of methane, propane, ethylene, and hydrogen. - The value of ignition current is inversely proportional to the value of source voltage. - The minimum ignition limit currents increase sharply at more than 2 [A]. The reason is caused by overheating the electrode.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.8
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• pp.1606-1616
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• 2011

The blood pressure measuring equipment, which is being supplied and used most widely by being recognized convenience and accuracy now generally, is oscillometric blood pressure monitor. However, a change in blood pressure is basically influenced by diverse elements such as each individual's physiological status and physical condition. Thus, the measurement of blood pressure, which used single element called oscillation in blood pressure of being conveyed to cuff, is not considered on physiological elements such as cardiovascular system status and blood vessel stiffness index, and on external elements, thereby being quite in error. Accordingly, this study detected diverse bio-signals and body informations in each individual as the measurement subject such as ECG, PPG, and Korotkoff Sound in order to enhance convenience and accuracy of measuring blood pressure in the complex measurement equipment, thereby having extracted regression method for compensation in error of oscillometric blood pressure measurement on the wrist, and having improved accuracy of measuring blood pressure. To verify a method of improving accuracy, the blood pressure value in each of SBP, DBP, MAP was acquired through 4-stage experimental procedure targeting totally 51 subjects. Prior to experiment, the subjects were divided into two groups such as the experimental group for extracting regression method and the control group for verifying regression method. Its error was analyzed by comparing the reference blood pressure value, which was obtained through the auscultatory method, and the oscillometric blood pressure value on the wrist. To reduce the detected error, the blood pressure compensation regression method was calculated through multiple linear regression analysis on elements of blood pressure, individual body information, PTT, HR, K-Sound PSD change. Verification was carried out on improving significance and accuracy by applying the regression method to the data of control group. In the experimental results, as a result of confirming error on the reference blood pressure value in SBP, DBP, and MAP, which were acquired through applying regression method, the results of $-0.47{\pm}7.45$ mmHg, $-0.23{\pm}7.13$ mmHg, $0.06{\pm}6.39$ mmHg could be obtained. This is not only the numerical value of satisfying the sphygmomanometer reference of AAMI, but also shows the lower result than the numerical value in SBP : $-2.5{\pm}12.2$ mmHg, DBP : $-7.5{\pm}8.4$ mmHg, which is the mean error in the experimental results of Brram's research for verifying accuracy of Omron RX-M, which shows relatively high accuracy among wrist sphygmomanometers. Thus, the blood pressure compensation could be confirmed to be made within significant level.