• Archives of Reconstructive Microsurgery
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• v.3 no.1
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• pp.45-53
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• 1994

Suture microvascular anastomosis is time-consuming and tedious and demands long and continuous training. Techinique of anastomosis of microvessel was presented interrupted suture and continuous suture. Recently the unilink instrument system is created as a fast and simple method to achieve high patency rates without long and continuous training in the anastomosis of small vessels. The author experimentally studied the femoral artery of 20 mice(0.5-1.0mm, av. 0.7mm), the femoral vein of 20 mice(0.8-1.6mm, av. 1.2mm) after anastomosis with interrupted suture in 20 cases and continuous sutre in 20 cases. For the unilink apparatus we used the carotid arteries of 15 cases in 14 rabbits(1.0-1.6mm, av. 1.3mm) and facial veins of 12 cases in 14 rabbits(0.9mm-2.2mm, av. 1.5mm). A total of 27 arterial and venous anastomoses were performed. We examined the postoperative patency at immediate, 2 weeks, and 8 weeks. The results were as followings, 1. In the arterial anastomosis the rate of patency was 90%(18/20) in interrupted suture, 90%(18/20) in continuous suture and 93%(13/15) in unilink apparatus. In the venous anastomosis the rate of patency was 90%(18/20) in interrupted suture, 80%(16/20) in continuous suture and 100%(9/9) in unilink apparatus. 2. The mean time for completion of the arterial anastomosis were 12.2 minutes in interrupted suture group, 10.3 minutes in continouous suture group and 8.5 minutes in unillnk apparatus group. The mean time for completion of the venous anastomosis were 13.6 minutes in interrupted suture group, 11.0 minutes in continuous suture group and 6.2 minutes in unilink apparatus group. 3. At the histological examination of suture group, hyperplastic reaction of middle layer and subintimal hyperplasia were observed. In unilink apparatus group, the endothelium layer was continued and the thickness of vessel wall was decreased due to moderate atrophy of the media and mild degree of nonspecific chronic inflammation were seen around the unilink apparatus. 4. No significants was noticied in foreign body reaction among the interrupted, continuous and unilink apparatus group. 5. A case of the arterial anastomosis was released with acting out at 15 minutes after operation. 6. The important factors in the technical problems were accurate apposition of the cut vessel edges in suture group and the proper selection of the ring size and optimal fitting between two rings in unilink apparatus group. Even though the outer diamater of vessel in suture group was different from that in unilink apparatus group the unilink method provides a very safe, fast, and simple way to perform microvascular anastomoses especially in anastomosis of vein. But howerver suture was needed in vessels below 1 mm outer diamater. In that situation continuous suture was benefit than the interrupted suture in operation time.

• Journal of Korea Water Resources Association
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• v.40 no.9
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• pp.677-685
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• 2007

The objective of this study is to evaluate the applicability of multi-objective genetic algorithm(MOGA) in order to calibrate the parameters of conceptual rainfall-runoff model, Tank model. NSGA-II, one of the most imitating MOGA implementations, is combined with Tank model and four multi-objective functions such as to minimize volume error, root mean square error (RMSE), high flow RMSE, and low flow RMSE are used. When NSGA-II is employed with more than three multi-objective functions, a number of Pareto-optimal solutions usually becomes too large. Therefore, selecting several preferred Pareto-optimal solutions is essential for stakeholder, and preference-ordering approach is used in this study for the sake of getting the best preferred Pareto-optimal solutions. Sensitivity analysis is performed to examine the effect of initial genetic parameters, which are generation number and Population size, to the performance of NSGA-II for searching the proper paramters for Tank model, and the result suggests that the generation number is 900 and the population size is 1000 for this study.

• Korean Journal of Agricultural Science
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• v.20 no.2
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• pp.221-236
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• 1993

Economic conditions of Korean agriculture have been aggravated since farmers experienced the shortage of labor, instability of farm product price, lack of capital and pressure of opening domestic market. Nevertheless, agriculture must be maintained because structure of national economy can not be progressed without balanced growth of food industry. So the problem that we must solve is to keep agriculture competitive. In that case technology is important in terms of improving productivity, overcoming labor shortage and stabilizing price. This paper is to study the technology adoption on the farm level, focusing on the theories of technology adoption, their empirical test and effect of technology adoption on the farm household income. In this study five theories-independent model, linear model, middle class conservation model, modified middle class conservation model, basic needs and wealfare model- were introduced concerning differentiated technology adoption rate by farmers' class. Based on the survey of controlled strawberry farming in Nonsan County, Chungnam Province, who adopted six kinds of technology, modified middle class conservation model was found to explain five kinds of technology adoption pattern and linear model was useful to explain one kind of technology, that is, irrigation method, These results may mean that controlled strawbary cultivators of middle class were reluctant to accept new technology. There are many variables to effect on the technology accepting rate, that is, farmer's age, labor capacity, education level, cultivation career, size of total cultivated land, and size of strawberry farming land. LOGIT model was used to find which variable influence the technology adoption rate. Results of estimation showed that variables of cultivation career and total land size, of which coefficients were statistically significant at the 5 percent level, might be main influential factors in accepting more than three farming techniques. There was a significant income difference between farm households accepting new methods and those rejecting them. Especially in case of low class of farming group, income of farmers who was adopting new technology was examined to be much higher than that of farmers who did not adopt. This result suggests that new technology play an important role in increasing farm household income. Finally this study emphasized that there is a need to develop proper measure of technology transfer considering various socioeconomic conditions of farm households.

• Journal of the Korean Society of School Health
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• v.1 no.2
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• pp.50-65
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• 1988

This study was conducted in order to grasp the condition of about the school nurse's service and to offer the basic materials of improving the school health service. The objects were comprised of 98 volunteered school nurses who take service in the elementary school. The material of this study was the questionaire suited to the purpose of this research which has been made through studying references and this questionaire has been corrected and revised three times. All the questionaire written by school-nurses. The results are as follows; 1. General features of the objects of study Average age was 35.9 and average career was 9.2 years. Except working as school-nurse, the past career was that average clinical-field was 3.4 years and health service was 4 months. Their educational level was as high as 72.4% of the objects were graduated from above 3 years college and 89.8% were married. 76.5% have religions and 94.8% were working at with national and public schools. 99.0% were doing only nursing service. 2. The conditions of the school health resources. The ratio of school-nurse to students was one to 2630. School-nurse to classes, one to 49.3, and school-nurse to teachers, one to 54. For total amount of a year budget of school health, from three hundred thousands to fifty nine hundred thousands won was most common. Expenses for purchasing medicine were used most. 58.2% of school-nurses hasn't known a year budget. There was an organization for school health in 74.2% of schools. 42.9% of nursing rooms were in the center of school and 88.8% were on first floor. Nursing room were used alone without being used by another purpose and the room size of 71.6% was below 10 pyong. 3. The conditions of school health service Average users of nursing room were 413 a month. The most of them had digestive trouble. Sending letters to home was 15.9 times a year. The most contents of letters was about health education. Object spent much time managing nursing room. 4. The degree of school health service When 2 points was given to "perform" and 1 point was to "not perform" the total average was 1.75, health education 1.89, environmental management 1.86, plan of project and evaluation 1.83, management of nursing room 1.82, health management 1.78, run of school health organization 1.32. 5. Correlation between the school health services and variables (1) The part of project plan and evaluation of school health service has relationship to existence or none-existence of school health organization (P<0.01), past health service career (P<0.05), number of classes (P<0.01), number of students (P<0.01), sending letters to home about health education (P<0.01) and number of users (P<0.05). (2) The part of nursing room management has relationship to ages (P<0.05) past clinical career (P<0.05), number of classes (P<0.05), number of students (P<0.05) and sending letters to home about health education (P<0.01). (3) The part of health education has relationship to existence or none-existence of school health organization (P<0.05), past clinical career (P<0.05), the ratio of health management to school nurse's all work (P<0.05) and the ratio of health education to school nurse's all work (P<0.01). (4) The part of environmental management to ages (P<0.01), career as a school-nurse (P<0.01), salary step(P<0.01), sending letters to home about health education (P<0.01), sending all letters to home (P<0.001), the ratio of health management to school nurse's all work (P<0.05), the ratio of health education to school nurse's all work (P<0.05) and area of school-nurse's room to be used. (5) The part of school health organization management to number of classes (P<0.05). (6) The part of health management to number of classes (P<0.05), sending letters to home about health education (P<0.001), sending all of letters to home (P<0.01) and the ratio of health management to school nurse's all work (P<0.05). (7) The part of school health service to ages (P<0.05), past clinical career (P<0.05), past health career (P<0.01), number of classes (P<0.05), number of student (P<0.05), sending letters to home about health education (P<0.05), sending all letters to home (P<0.05), the ratio of health management to school nurse's all work (P<0.05), the ratio of health education to school nurse's all work (P<0.01) and area of school - nurse's room to be used (P<0.05). ## Suggestion for further studies are as follows. 1. School-nurse should exert herself to advance a quality to take care of school population's health. 2. It is necessary that systematic support required to keep school population's health. 3. Home, school and community should make efforts cooperatively and the proper roles of students, teachers, health team members and parents must be achieved.

• Korean Journal of Optics and Photonics
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• v.12 no.3
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• pp.240-249
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• 2001

A high speed ultra-compact lens with a diffractive optical element (DOE) is designed, which can be applied to mobile communication devices such as IMT2000, PDA, notebook computer, etc. The designed hybrid lens has sufficiently high performance of less than f/2.2, compact size of 3.3 mm (1st surf. to image), and wide field angle of more than 30 deg. compared with the specifications of a single lens. By proper choice of the aspheric and DOE surface which has very large negative dispersion, we can correct chromatic and high order aberrations through the optimization technique. From Seidel third order aberration theory and Sweatt modeling, the initial data and surface configurations, that is, the combination condition of the DOE and the aspherical surface are obtained. However, due to the consideration of diffraction efficiency of a DOE, we can choose only four cases as the optimization input, and present the best solution after evaluating and comparing those four cases. On the other hand, we also report dramatic improvement in optical performance by inserting another refractive lens (so-called, field flattener), that keeps the refractive power of an original DOE lens and makes the petzval sum zero in the original DOE lens system. ystem.

• The Korean Journal of Physiology
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• v.2 no.1
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• pp.39-45
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• 1968

Recently, in this department, pressure-displacement curve and breaking tension of dog and human tympanic membrane were studied using intact, fresh or dried tympanic membrane attached to external auditory meatus. However, physical property, proper elasticity-Young Modulus, of the tympanic membrane has not been clarified yet. Present study is attempted to further clarify proper Young Modulus of tympanic membrane, and to distinguish possible difference between layer of stratum radiatum and layer of stratum circulare of tympanic membrane in breaking tension and in Young Modulus. Tympanic membrane was excised from sacrificed dog, and preparation was made into the size of approximately 1 mm in width and 3 mm in length. In fresh or dried tympanic membrane, which was dried at $80^{\circ}C$ for 24 hrs., some preparations were made along the long axis parallel to the fibers of radial direction, and others were made along the long axis perpendicular to the radial fibers-circular direction. Breaking tension and displacement according to loading, were measured and Young Modulus was calculated in tympanic membrane preparations under the different experimental conditions. Results obtained are summarized as follows : 1. Young Modulus of fresh tympanic membrane in radial direction was $6.57{\times}10^8\;dyne/cm^2$, and that of fresh preparation in circular direction was $1.68{\times}10^8\;dyne/cm^2$. The Young Modulus of fresh tympanic membrane in radial direction resembles to that of silk and whale moustache. In dried tympanic membrane, Young Modulus of preparation of radial direction was $30.2{\times}10^8\;dyne/cm^2$ and that of preparation in circular direction was $25.0{\times}10^8\;dyne/cm^2$. 2. Breaking tension of fresh tympanic membrane was 44.9 gm/mm in radial preparation, and 7.9 gm/mm in circular preparation. In dried tympanic membrane, breaking tension was 46.7 gm/mm in preparation of radial direction, and 17.2 gm/mm in preparation of circular direction. 3. Much smaller breaking tension of the circular preparation-one fifth to the radial preparation-seemed to be responsible for the higher incidence of circular fiber breaking in tympanic membrane performation caused by trauma or sudden change in atmospheric pressure. 4. The correlation seemed to be very close between breaking tension and Young Modulus in tympanic membrane.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.46 no.6
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• pp.27-34
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• 2009

Block truncation coding (BTC) is a simple and efficient image compression technique. However, it yields images of unacceptable quality and significant blocking effects are seen when the block size is increasing. Ordered dither block truncation coding (ODBTC) was proposed to solve above problem maintaining the same compression capability. In this paper, we propose a data hiding method which can be applied to halftone images. EMD was developed by Zhang and Wang [6] for data hiding in the grayscale image. Therefore, EMD is not proper for bitmap images. In this paper, we show that EMD can be used to apply bitmap halftone image. In our experiments, we prove that our method is efficient in a halftone image.

• Communications for Statistical Applications and Methods
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• v.19 no.1
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• pp.47-55
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• 2012

The newly revised bioequivalence guideline of Korea allows the add-on test since July 1, 2008 when the initial bioequivalence trial fails to show the equivalence of two drugs. The statistical model of the add-on test and its two stage testing procedures are discussed. Some statistical points of consistency test in the add-on test are considered and the issue on the sample size of add-on test is discussed. Some reasonable alternative like Japan's guideline for bioequivalence studies is recommended to secure the proper use of an add-on study through some simulation studies.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.5
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• pp.563-571
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• 2012

In 3D integration package using TSV technology, bonding is the core technology for stacking and interconnecting the chips or wafers. During bonding process, however, warpage and high stress are introduced, and will lead to the misalignment problem between two chips being bonded and failure of the chips. In this paper, a finite element approach is used to predict the warpages and stresses during the bonding process. In particular, in-plane deformation which directly affects the bonding misalignment is closely analyzed. Three types of bonding technology, which are Sn-Ag solder bonding, Cu-Cu direct bonding and SiO2 direct bonding, are compared. Numerical analysis indicates that warpage and stress are accumulated and become larger for each bonding step. In-plane deformation is much larger than out-of-plane deformation during bonding process. Cu-Cu bonding shows the largest warpage, while SiO2 direct bonding shows the smallest warpage. For stress, Sn-Ag solder bonding shows the largest stress, while Cu-Cu bonding shows the smallest. The stress is mainly concentrated at the interface between the via hole and silicon chip or via hole and bonding area. Misalignment induced during Cu-Cu and Sn-Ag solder bonding is equal to or larger than the size of via diameter, therefore should be reduced by lowering bonding temperature and proper selection of package materials.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.13 no.1
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• pp.47-56
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• 2010

The main objectives of this comparative study were 1) to quantify the potential contribution of wood chips to revegetation on the cut slope in a constructed area, 2) to compare the floristic similarity of species composition whether existing of wood chips in the soil media or not. Wood chips were combined with soil media in the ratio of 30%. The thin layer (1 cm, 3 cm) soil media revegetation methods and the thick layer (10 cm) soil media revegetation method were constructed on the cut slopes by machineries respectively. Also, comparative experiments the existence of wood chips in the soil media were conducted to evaluate the effects of wood chips on revegetation works. The total size of quadrat was $300m^2$ ($100m^2{\times}3$). The results of monitoring for 3 years on cut slopes were as follows: 1) All the quadrat existed in the proper range for vegetation. 2) Species richness of quadrat including wood chips was 10% more than those of commercial soil medias. 3) The coverage rates of quadrat including wood chips were similar or superior to those of conventional methods. It can be concluded that the use of wood chips would be effective to promote establishment of diverse landscape and vegetation. However, it behooves to continue monitoring on succession of vegetation for ecological restoration. Finally, adequate wood chips deposit and gathering methods should be studied properly.