• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.3B
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• pp.277-284
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• 2010

To examine how the width of connecting channels, the width of the Kumho lock gate, and the opening/shutting criteria of the Yeongam connecting channel lock gate affect the flood stage of Lake Yeongsan, Lake Yeongam, and Lake Kumho, located in the lower reaches of the Yeongsan River, unsteady flood routing was performed by connecting the three lakes into a single interlinked system. The coupled operation of the three lakes was found to have little effect when the widths of the lock gates and the Yeongam and Kumho connecting channels are set at the current level. The most effective way to lower the water level in Lake Yeongsan was to widen the Yeongam connecting channel, but this caused the water level in Lake Yeongam to rise. To lower the increased water level in Lake Yeongam by utilizing the water storage capacity of Lake Kumho, it was necessary to widen both the Kumho lock gate and the Kumho connecting channel. It was found that the optimum opening/shutting criterion for the Yeongam connecting channel lock gate is approximately EL.(+)0.8 m under the simulated conditions used in this study and the criterion allows of maximal lowering of the water levels in Lake Yeongam and Lake Kumho while maintaining a near-constant water level in Lake Yeongsan.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.3
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• pp.306-313
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• 2005

Statement of problem. There have been many studies about marginal discrepancy of single restorations made by various systems and materials. But most of statistical inferences are not definite because of sample size, measurement number, measuring , instruments, etc. And there have been few studies about the marginal fit of Computer-aided Cercon crowns. Purpose. The purpose of this study was to compare the marginal fit of the anterior single restorations made using computer-aided milled Cercon crowns with metal-ceramic restorations and to obtain more accurate information by using a large enough sample size and by making sufficient measurements per specimen. Material and methods. The in vitro marginal discrepancies of computer-aided milled Cercon crowns and control groups (metal ceramic crowns) were evaluated and compared. The crowns were made from one extracted maxillary central incisor prepared by milling machine. 30 crowns per each system were fabricated. Measurements of a crown were recorded at 50 points that were randomly selected for marginal gap evaluation. Parametric statistical analysis was performed for the results. Results. The means and standard deviations of the marginal fit were 85$\pm$22$\mu$m for the control group and 91$\pm$15$\mu$m for the Cercon crowns. The t-test of the marginal discrepancies between Cercon crowns and metal-ceramic crowns were performed. Significant differences were not found between groups (P=0.230>.05). Based on the criterion of 120$\mu$m as the limit of clinical acceptability, the mean marginal fits of Cercon crowns and metal-ceramic crowns were acceptable. Conclusion. Within the limitations of this in vitro study, the following conclusions were drawn: 1. Mean gap dimensions and standard deviations at the marginal opening for maxillary incisal crowns were 85$\pm$22$\mu$m for the control (metal-ceramic crowns), 91$\pm$15$\mu$m for Cercon crowns. 2. The Cercon crowns showed slightly larger marginal gap discrepancy than the control but marginal gap between Computer-aided milled Cercon crowns and metal ceramic crowns did not showed significant difference (P>.05). 3. The Cercon crowns and metal ceramic crowns showed clinically acceptable marginal discrepancy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.9
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• pp.5820-5825
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• 2014

The aim of this study was to verify the suitability or unsuitability of Korean body types by measuring the opening force criteria of an air pressurized access door to a smoke control zone. The opening force criteria were verified by comparing the NFSC 501A, NFPA 92A and BS-EN 12101-6 based on the body standards information from the Korean Agency for Technology and Standards. When measuring the opening forces, the posture of the body should be standing upright and pushing an access door with the right hand, which is a criterion for designing doors. As a result of analyzing the actual measurement results, the pushing force of men and women in their 30's was the maximum value and the forces in those in their 60's was the minimum value. In addition, the deviations in the pushing forces varied considerably. As a result of comparing the NFSC 501A, the men showed lower values than the criteria in every gender and age variable except for the 20's, 30's and 50's variable. A comparison of the criteria of NFPA 92A showed that the mean of the measured values from every gender and age was also lower than the criteria. In addition, when comparing the criteria of BS-EN 12101-6, it was found that the men in every age variable were higher than the criteria. On the other hand, the women in every age variable were lower than the criteria. Therefore, considering the Korean body type against the Western body type, it was decided that the opening force of an access door to a smoke control area to make a downward adjustment should be 110 N in the local criteria. Furthermore, the criteria should consider the characteristics of buildings and users because an optional application of the international standard is not necessarily suitable for local situations.

• The Journal of Korean Academic Society of Nursing Education
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• v.9 no.2
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• pp.264-275
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• 2003

The purpose of this study were to develop a smoking preventive education program for elementary students and evaluate it's effectiveness. This study was a quasi experimental study under the nonequivalent control group with pretest-posttest design. The subjects of this study were 62 who are attending elementary school(31 for each group), 2 different district elementary school. The subjects were matched by grade, similar in anti-smoking educational background of smoking, as well as their residence and income level of their families. The instruments used in this study was 18 criterion referenced test items modeled by Dick & Carey that were developed by researchers for evaluating the subjects' knowledge and attitude about smoking. A pretest was administered a week before treatment The program given to the experimental group is composed of the texts explaining the poisonous substances in tobacco, social and cultural harmfulness of smoking to the body and psychology, indirect smoking, smoking of pregnant women, motives of smoking, refusal skills of smoking; and for the subjects' understanding and the better results of study - pictures, role play, discussion, text through computer based multi-media, puzzle searching for hidden pictures, cross-word puzzle, and finally compensation. The data were collected for 50 days form mid- September to the end of October in the year of 2000, composed of formative evaluation, pre-test and summative evaluation via 2 sessions. Accordingly, the collected data were analysed by t-test, paired t-test, repeated measure ANOVA by the SAS program. This research summarize the findings as follows; 1. There was a significant difference in knowledge between the experimental group(after 1 wks t=10.4680, p=.0001; after 4 wks t= 9.310, p=.0001) and control group(after 1 wks t=0.0420, p= .9669; after 4 wks t= -0.378 p=.7079) in between the results of 1 and 4 week after education in summative evaluation (F=27.45, P=.0001). 2. There was non statistical significant difference in attitude between the experimental group (after 1 wks t=1.2292, p=0.2286 ; after 4 wks t=1.330, p=0.1935) and control group (after 1 wks t=0.1819, p=0.8569 ; after 4 wks t=0.2970, p=0.7685) in between the results of 1 and 4 week after education in summative evaluation(F=0.71, P=0.494). To sum up, the statistics of conclusive analysis evaluative for the children under school age of the 'knowledge acquisition' about smoking harmfulness. On the other hand, as there was already sound attitude about smoking, the evaluation of attitude was non significant difference between control group and experimental group, just there was partially significant difference.

• Korean journal of applied entomology
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• v.48 no.1
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• pp.87-94
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• 2009

KNI3126 which is the eco-friendly material made by plant extracts - neem and matrine - have been evaluated for efficacies against 6 main pests and toxicity on natural enemies. Insecticidal efficacies of KNI3126 against plant hopper were above 95% at 5 days after treatment (DAT), whereas pesticidal effects against the cotton aphid were above 95% at 3 DAT and slightly decreased at 5 DAT. Insecticidal efficacy against the palm thrips resulted in lower control value as 68.1% than that of chemical insecticides. KNI3126 showed more than 95% control value against diamond back moth, suggesting that it could suppress the population of pest hard to control as eco-friendly material. Mortalities against two-spotted spider mite were about 80% at 1 DAT and over 90% at 5 DAT, respectively. For evaluation of the toxicity on natural enemies, effect against predatory natural enemy was classified as moderate selective toxicity based on the criterion of International Organization of Bio-Control (IOBC), whereas against parasitic natural enemies was found to be relatively safe. Repellent effect was weak against plant hopper, but strong against two-spotted spider mite. In the toxicity test for safety, KNI3126 was classified as the lowest level at acute oral, acute dermal and fish toxicity test and did not induce the irritancy at skin irritation test and eye irritation test.

• Journal of Biosystems Engineering
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• v.16 no.3
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• pp.248-262
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• 1991

Simulation model was developed to analyze drying process for tray type red pepper dryer and validated by experiments. This model could predict satisfactorily temperatures and moisture contents of red pepper and temperatures of drying air during drying. Optimize algorithm was developed to search control valiables (drying air temperature, air recycle ratio and air flow rate) of red pepper dryer based on a criterion of minimizing energy consumption under the constraint conditions that statisfied carotenoid retension of at least 210mg per 100g dry matter, the moisture content of bottom layer of 15% (d.b) and drying time of less than 35 hours. Step changes in drying air temperature and air recycle ratio were considered in the optimization. In single step in control variables, the difference of the moisture content between top layer and bottom layer was great and more fan power was required. As the drying trays were exchanged when the moisture content of bottom layer reached to 100% (d.b), fifty percent of energy was saved and the difference of moisture content was little. In double step changes in control variables, optimal conditions were found by changing the step when the moisture content of bottom layer reached to 100% (d.b) (about 19.8 hours from starting drying). Optimum air flow rate was $18.1cmm/m^2$. Optimum drying air temperature and air recycle ratio in the first step was $55.8^{\circ}C$ and 0.80, and in the second step $65.6^{\circ}C$ and 0.88, respectively. In triple step changes in control variables, the optimal conditions were found by changing the steps when the moisture content of bottom layer reached to 250% (d.b) and 150% (d.b). Optimal air temperatures were $66.2^{\circ}C$, $58.4^{\circ}C$ and $66.9^{\circ}C$, and optimal air recycle ratios were 0.778, 0.785, 0.862 at each step, respectively. Optimal air flow rate was $18.9cmm/m^2$. The best operating mode was triple step mode considering energy consumption, drying time, fan power, and quality of dried red pepper. When the triple step mode was used to dry the red pepper, the energy consumption was about 16.5%~57.2% less than that of the single step mode and the drying time was 6.6 hours shorter than that of the double step mode.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.13 no.1
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• pp.5-14
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• 2003

Principles of a novel pulse growing method are described. The method realized in the crystal growing on a seed from melts under raw melt feeding provided a more reliable control of the crystallization process when producing large alkali halide crystals. The slow natural convection of the melt in the crucible at a constant melt level is intensified by rotating the crucible, while the crystal rotation favors a more symmetrical distribution of thermal stresses over the crystal cross-section. Optimum rotation parameters for the crucible and crystal have been determined. The spatial position oi the solid/liquid phase interface relatively to the melt surface, heaters and the crucible elements are considered. Basing on that consideration, a novel criterion is stated, that is, the immersion extent of the crystallization front (CF) convex toward the melt. When the crystal grows at a <> CF immersion, the raised CF may tear off from the melt partially or completely due to its weight. This results in avoid formation in the crystal. Experimental data on the radial crystal growth speed are discussed. This speed defines the formation of a gas phase layer at the crystal surface. The layer thickness il a function of time a temperature at specific values of pressure in the furnace and the free melt surface dimensions in the gap between the crystal and crucible wall. Analytical expressions have been derived for the impurity component mass transfer at the steady-state growth stage describing two independent processes, the impurity mass transfer along the <> path and its transit along the <> one. The heater (and thus the melt) temperature variation is inherent in any control system. It has been shown that when random temperature changes occur causing its lowering at a rate exceeding $0.5^{\circ}C/min$, a kind of the CF decoration by foreign impurities or by gas bubbles takes place. Short-term temperature changes at one heater or both result in local (i.e., at the front) redistribution of the preset axial growth speed.

• Journal of Internet Computing and Services
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• v.10 no.3
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• pp.1-8
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• 2009

The primary tasks of a workflow management system specify workflow models with respect to resource, control-flow, data-flow, functional, and operational perspectives, and to enact their workcases (workflow instances). In terms of enacting workflow models, the essential criterion grading the quality of the system is "how much is the system able to guarantee the correctness of workflow models' enactment?". Particularly, the workflow determinacy problem, which may be caused by the interference of the control-flow and the data-flow specifications, is the most challenging issue in guaranteeing the correctness of the system. We are able to solve the problem by either of the following two approaches-analysis of workflow model and verification of workflow enactment. In the paper, we propose a technique that guarantee the system's correctness through verifying workflow enactment. In other words, the technique is able to detect the conflicts of control-flow and data-flow enactments existing on a workflow model, which causes the system to be non-determinant in enacting workflow models. Finally, by applying the technique to the e-Chautauque workflow management system developed by the authors' research group, we prove that the technique is a feasible solution for the workflow determinacy problem.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.3
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• pp.230-238
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• 2003

An effect on the enhancing production of hollow 'jumbo' structures and the condition of artificial reefs (dice and hollow jumbo structure) by side scan sonar were described. The experiment of the capture of fish in the jumbo structures and control site (non-artificial site) by trammel net and traps was done twice every year from 1998 to 2000. The relative catches by trammel net between in the jumbo structure and in the control site was significantly different in number and in weight at 5% level and also that by traps significantly different in weight. The t-test of the catch of finespotted flounder showed that the hollow jumbo structure was regarded as a breeding field because the average size of the flounder in the jumbo site was smaller than that in the control site. The search on the condition of the artificial reefs (dice and hollow jumbo structure) was performed by side scanning sonar which showed various phase of it such as accumulated, dispersed, scouring and partly buried. The result implied that in the area of sand bottom with strong tide like the western sea of Korea, the current criterion for constructing artificial reef should be modified because of the sand moving on the bottom.

• Journal of Korean Academy of Nursing
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• v.24 no.3
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• pp.484-498
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• 1994

The purpose of this study was to investigate the home care needs in a rural county as a basic study to develop a Korean home care model. A stratified cluster sampling method was used to select 1, 352 household which accounted for 8.8% of Youn Cheon County population. A Standard criterias for home care subject were delineated by five nursing professors representing five different areas of nursing specialty. The developed criteria for home care subjects were as below, 1) Patients who had been discharged from hospital during the previous week. 2) Patients with special medical devices 3) Newborns and the mothers. 4) The chronically ill with poor recovery or control of disease. 5) Subjects with poor health care behavior or ability 6) Subjects with poor social support and / or family resources. 7) Subjects with health related educational needs. Three types of questionnaires were developed to screen home care subjects, one for adults, one for infants and one for the elderly. Also different questionnaire items were developed to evaluate the control and self care ability of chronically ill subjects. After training in interview methods for 2 days, 39 interviewers visited individual households for interviews. As the results of the study showed that 14.1％ of adult subjects and 76.5% of infants and child were judged as having at least one criterion related to home care need, 15.69% of adults and 53% of elderly had at least one chronic illness. The most prevalent chronic illnesses were hypertension, skeletal-neurological disease and diabetes. The prevalence of subjects with home care needs were, those with poor health care behavior(8.89%), with health-re-lated educational needs(8.71%), with poor recovery or control of disease (3.52%), and with poor social support and inadequate family resources(3.19%). There were only 0.3%, 0.37%, 0.11% who were discharged patients, patients with medical devices, or newborns respectively. Thus, the largest home care client group were those who need direct health care and health education. Seventy five percent of the subjects responded that they were willing to use and pay for home care service if it is offered in the future. It is suggested that recently discharged patients and patients with special medical devices can be cared for by hospital based home care nurses, but other home care clients can be cared for by com-munity based home care nurses.