• Journal of Chest Surgery
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• v.43 no.6
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• pp.602-613
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• 2010

Background: As life expectancy has been increased, the cardiac valve disease has been increased. In past, mechanical valve for valve replacement surgery was used widely, but it has many weaknesses, such as hemorrhage, teratogenic effect caused by warfarin, acute mechanical failure, taking warfarin during life, etc. So, the tissue valve is used widely and researches for durability of tissue valve are in progress. Tissue valves being used are all imported in Korea, and there is a lack of information on its geometry and design. So, we studied the geometry of porcine aortic and pulmonary valve, and tried to suggest theoretical basis for making the aortic and pulmonary valve. Material and Method: We harvested aortic and pulmonary valves of 25 pigs and measured the geometry of valve at fresh and glutaraldehyde (GA) fixed state. In each group, we measured the diameter of the base, diameter of commissure, valve height, commissural height, etc. Also, for making implantable porcine and bovine pericardial valve, we designed the valve stent form, thickness, height, and leaflet size, form, thickness by different size of valve. Result: The aortic and pulmonary valve geometry and ratio were measured in each group. The right coronary cusp of aortic valve and right facing cusp of pulmonary valve was bigger than other cusps and non coronary cusp was smaller than others (RCC: NCC : LCC=1 : 0.88 : 1). Valve height was correlated to the leaflet size. We designed the outer diameter of stented porcine aortic valve from 19 mm to 33 mm and designed stent height and width, using previous measured ratio of each structure, stent thickness, working thickness (for making valve). Also, we designed the size of stent and form for stented bovine pericardial valve, considering diameter of valve, leaflet length, height and leaflet minimum coaptation area. Conclusion: By measuring of 25 pig's aortic and pulmonary valve geometry and ratio, we can make theoretical basis for making implantable stented porcine valve and bovine pericardial valve in various size. After making implantable valve using these data, it is necessary to do in vivo and in vitro researches, furthermore.

• The Journal of Korean Academy of Prosthodontics
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• v.50 no.3
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• pp.162-168
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• 2012

Purpose: Teeth are generally exposed when people smiling. Moreover, the exposed teeth and soft tissue when smiling becomes an important guideline for esthetically prosthetic restoration. This research is to compare and find out differences of Korean young men's smile living in presence and twenty years ago. Materials and methods: Subjects, 100 young men (50 male and 50 female), were required about several aspects; normally developed physical condition, no psychological or genetic disorders, a fine face with no loss of teeth, no experience in orthodontic or prosthetic treatment, relatively normal occlusion, aged between 20-29. The photos of the subject at rest position and front face when fully smiled were taken three times. 100 photos (50 male and 50 female) were chosen at random from the 240 university students' smile photos taken by Yoon and his colleagues in 1991. By Hulsey's method of measuring smile, several factors; the change of upper lip curvature, the change of the relation between the upper lip and teeth, parallelism between Mx. incisor and lower lip, contact relation between Mx. incisor and lower lip and teeth displayed in a smile, were measured and analyzed. Meanwhile, ten dentists assessed aesthetic evaluation about men and women's smile for twice and recorded and compared smile score. The -test (P<.05) was used to compare the measured value. The difference of smile score was analyzed by t-test (P<.05). Results: The smile score calculated in 2011 (60.22) was higher than that of 1991 (52.80). Among five measurement categories, the noticeable difference was distinguished from two factors; the change of upper lip curvature and contact relation between Mx. incisor and lower lip. Conclusion: The Korean young men's smile has been considerably improved for twenty years. And it is found that the change of upper lip curvature plays an important role, that is, the smile formed with an ascended labial commissure has been increased significantly.

• Journal of Chest Surgery
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• v.35 no.7
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• pp.530-534
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• 2002

Background: In aortic surgery, division and ligation of the left brachiocephalic vein(LBV) may improve exposure of the aortic arch but controversy continues about the safety of this division and whether a divided vein should be reanastomosed after arch replacement was completed. The safety of LBV division and the fate of the left subclavian venous drainage after LBV division were studied. Material and Method: From November 1998 to January 2001, planned division and ligation of the LBV on the mid-line after median sternotomy was peformed in 10 patients during the aortic surgery with the consideration of local anatomy and distal aortic anastomosis. Assessment for upper extremity edema and neurologic symptoms, measurement of venous pressure in the right atrium and left internal jugular vein, and digital subtraction venography(DSV) of the left arm were made postoperatively. Result: In 10 patients there was improvement in access to the aortic arch for procedures on the ascending aorta or aortic arch. The mean age of patients was 62 years(range 24 to 70). Follow-up ranged from 3 weeks to 13 months. One patient died because of mediastinitis from methicilline-resistant staphylococcus aureus strain. All patients had edema on the left upper extremity, but resolved by the postoperative day 4. No patient had any residual edema or difficulty in using the left upper extremity during the entire follow-up period. No patient had postoperative stroke. Pressure difference between the right atrium and left internal jugular vein was peaked on the immediate postoperative period(mean peak pressure difference = 25mmHg), but gradually decreased, then plated by the postoperative day 4. In all DSV studies left subclavian vein flowed across the midline through the inferior thyroid venous plexus. Conclusion: We conclude that division of LBV is safe and reanastomosis is not necessary if inferior thyroid vein, which is developed as a main bridge connecting the left subclavian vein with right venous system, is preserved.

• Journal of agricultural medicine and community health
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• v.28 no.2
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• pp.155-169
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• 2003

Objectives: The purpose of this study is to provide data for the improvement of hypertension management of community health practitioner posts through the study on hypertension management in community health practitioner posts. Methods: A questionnaire was mailed to 700 community health practitioners and 205 of them responded during the period from March 13, 2003 to May 13. The survey results were analyzed using SPSS program, version 11. Results: The results are as follows; 1. There are two major activities in a hypertension prevention project for community: health education and early detection. About 57% of community health care practitioners perform a health education for community people four times a year. The 64.5% of them used the materials for health education provided from a community health center and 22.1% of them performed a post-evaluation. The main method of early detection of hypertension was measurement of blood pressure of person to visit, which was 96.1%. Other methods included home visiting(89.3%), a referral from community hospitals and other resources(49.1%), health promotion events(39.5%), and a review of medical records(35.7%). 2. For the registration and management of patients with hypertension, about 36% of community health centers used a special form and more than 50% of them have registered patients who were managed by other health care institutions in the community. A computerized program was used for the management of patients with hypertension in 68.5% of them. More than 60% of them responded that it was used for report, treatment, and follow-up of patients with hypertension.

• Korean Journal of Cognitive Science
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• v.19 no.4
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• pp.331-367
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• 2008

This study aims to validate a web-based neuropsychological testing tool developed by Kwak(2007) and to suggest solutions to potential problems that can deteriorate its validity. When it targets a wider range of subjects, a web-based neuropsychological testing tool is challenged by high drop-out rates, lack of motivation, lack of interactivity with the experimenter, fear of computer, etc. As a possible solution to these threats, this study aims to redesign the user interface of a web-based attention testing tool through three phases of study. In Study 1, an extensive analysis of Kwak's(2007) attention testing tool was conducted to identify potential usability problems. The Heuristic Walkthrough(HW) method was used by three usability experts to review various design features. As a result, many problems were found throughout the tool. The findings concluded that the design of instructions, user information survey forms, task screen, results screen, etc. did not conform to the needs of users and their tasks. In Study 2, 11 guidelines for the design of web-based attention testing tools were established based on the findings from Study 1. The guidelines were used to optimize the design and organization of the tool so that it fits to the user and task needs. The resulting new design alternative was then implemented as a working prototype using the JAVA programming language. In Study 3, a comparative study was conducted to demonstrate the excellence of the new design of attention testing tool(named graphic style tool) over the existing design(named text style tool). A total of 60 subjects participated in user testing sessions where their error frequency, error patterns, and subjective satisfaction were measured through performance observation and questionnaires. Through the task performance measurement, a number of user errors in various types were observed in the existing text style tool. The questionnaire results were also in support of the new graphic style tool, users rated the new graphic style tool higher than the existing text style tool in terms of overall satisfaction, screen design, terms and system information, ease of learning, and system performance.

• Journal of Chest Surgery
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• v.37 no.1
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• pp.1-10
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• 2004

Background: Currently, the cardiopulmonary machine with non-pulsatile pumps, which are low in internal circuit pressure and cause little damage to blood cells, is widely used. However, a great number of experimental studies shows that pulsatile perfusions are more useful than non-pulsatile counterparts in many areas, such as homodynamic, metabolism, organ functions, and micro-circulation. Yet, many concerns relating to pulsatile cardiopulmonary machines, such as high internal circuit pressure and blood cell damage, have long hindered the development of pulsatile cardiopulmonary machines. Against this backdrop, this study focuses on the safety and effectiveness of the pulsatile cardiopulmonary machines developed by a domestic research lab. Material and Method: The dual-pulsatile cardiopulmonary bypass experiment with total extracorporeal circulation was conducted on six calves, Extracorporeal circulation was provided between superior/inferior vena cava and aorta. The membrane oxygenator, which was placed between the left and right pumps, was used for blood oxygenation. Circulation took four hours. Arterial blood gas analysis and blood tests were also conducted. Plasma hemoglobin levels were calculated, while pulse pressure and internal circuit pressure were carefully observed. Measurement was taken five times; once before the operation of the cardiopulmonary bypass, and after its operation it was taken every hour for four hours. Result: Through the arterial blood gas analysis, PCO2 and pH remained within normal levels. PO2 in arterial blood showed enough oxygenation of over 100 mmHg. The level of plasma hemoglobin, which had total cardiopulmonary circulation, steadily increased to 15.87 $\pm$ 5.63 after four hours passed, but remained below 20 mg/㎗. There was no obvious abnormal findings in blood test. Systolic blood pressure which was at 97.5$\pm$5.7 mmHg during the pre-circulation contraction period, was maintained over 100 mmHg as time passed. Moreover, diastolic blood pressure was 72.2 $\pm$ 7.7 mmHg during the expansion period and well kept at the appropriate level with time passing by. Average blood pressure which was 83$\pm$9.2 mmHg before circulation, increased as time passed, while pump flow was maintained over 3.3 L/min. Blood pressure fluctuation during total extracorporeal circulation showed a similar level of arterial blood pressure of pre-circulation heart. Conclusion: In the experiment mentioned above, pulsatile cardiopulmonary machines using the doual-pulsatile structure provided effective pulsatile blood flow with little damage in blood cells, showing excellence in the aspects of hematology and hemodynamic. Therefore, it is expected that the pulsatile cardiopulmonary machine, if it becomes a standard cardiopulmonary machine in all heart operations, will provide stable blood flow to end-organs.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.6
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• pp.74-83
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• 2011

The high-pass transportation information system directly collects section information by using probe cars and therefore can offer more reliable information to drivers. However, because the running condition and features of probe cars and statistical processing methods affect the reliability of the information and particularly because the section travel time is greatly influenced by whether there has been delay by signals on urban roads or not, there can be much deviation among the collected individual probe data. Accordingly, researches in multilateral directions are necessary in order to enhance the credibility of the section information. Yet, the precedent studies related to high-pass information provision have been conducted on the highway sections with the feature of continuous flow, which has a limit to be applied to the urban roads with the transportational feature of an interrupted flow. Therefore, this research aims at analyzing the features of high-pass transportation data on urban roads and finding a proper processing method. When the characteristics of the high-pass data on urban roads collected from RSE were analyzed by using a time-space diagram, the collected data was proved to have a certain pattern according to the arriving cars' waiting for signals with the period of the signaling cycle of the finish node. Moreover, the number of waiting for signals and the time of waiting caused the deviation in the collected data, and it was bigger in traffic jam. The analysis result showed that it was because the increased number of waiting for signals in traffic jam caused the deviation to be offset partially. The analysis result shows that it is appropriate to use the mean of this collected data of high-pass on urban roads as its representative value to reflect the transportational features by waiting for signals, and the standard of judgment of delay and congestion needs to be changed depending on the features of signals and roads. The results of this research are expected to be the foundation stone to improve the reliability of high-pass information on urban roads.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.4
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• pp.25-30
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• 2008

Purpose: In this paper, we have analyzed the problems of the Oh's report which is used to the basic data for supply and demand of medical technicians and studied a proposal for improvement to control system and supply and demand of korean optometrists. Methods: We have analyzed errors of Oh's report including supply and demand for medical technicians and management policy, expecting number for future optician, inaccurate estimation by limited data (employment rate, retirement rate, mortality rate) and an incorrect method of measurement for future supply and demand. Results: Oh's report showed the 18% error for estimation of supply which exclude the irregular entrance students. The estimation of supply was calculated by graduation rate 62.6% (college and University of Technology are 78.9% and 85.98% respectively), employment rate 65.8% (the average employment between 2002 and 2007 is 73.96%) and retirement rate is 2.3% (the retirement of pharmacists is 1.3%) but it showed the significant differences to objective data. For estimate the suitable ratio of optometrists to the population, the ratio use of medical facilities by an age group was used, and suggested spectacle wearers 1,280 persons (populations 2,928 persons) per optometrist but the different from reference of Germany (4,706 persons), America (1,789 persons) and Korea (1,825 persons/an optometrist) are applied to estimation on supply. This report applied the low employment rate and argued that maintain the present situation, but claimed that utilize unemployment persons. The above result has induced double weighting effect on estimation of supply. Conclusions: To solve the related problems of supply and demand, we have to make a search for exact data and optimum application model, have to take an example of nation similar job category as Germany and the research result of the job satisfaction into consideration. After we get the integrated research result, we must carried out the policy with fairness and balance for the estimation of supply and demand. Therefore exact research is required prior to beginning policy establishment, government and related group have to make a clear long-term plan and permanent organization for medical technician to establish supply and demand of medical technician.

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.3
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• pp.31-38
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• 2019

This study quantified, through a direct harvesting method, storage and annual uptake of carbon from open-grown trees for three landscape tree species frequently planted in the southern region of Korea, and developed quantitative models to easily estimate the carbon reduction by tree growth for each species. The tree species for the study included Camellia japonica, Lagerstroemia indica, and Quercus myrsinaefolia, for which no information on carbon storage and uptake was available. Ten tree individuals for each species (a total of 30 individuals) were sampled considering various stem diameter sizes at given intervals. The study measured biomass for each part of the sample trees to quantify the total carbon storage per tree. Annual carbon uptake per tree was computed by analyzing the radial growth rates of the stem samples at breast height or ground level. Quantitative models were developed using stem diameter as an independent variable to easily calculate storage and annual uptake of carbon per tree for study species. All the quantitative models showed high fitness with $r^2$ values of 0.94-0.98. The storage and annual uptake of carbon from a Q. myrsinaefolia tree with dbh of 10 cm were 24.0 kg and 4.5 kg/yr, respectively. A C. japonica tree and L. indica tree with dg of 10 cm stored 11.2 kg and 8.1 kg of carbon and annually sequestered 2.6 kg and 1.2 kg, respectively. The above-mentioned carbon storage equaled the amount of carbon emitted from the gasoline consumption of about 42 L for Q. myrsinaefolia, 20 L for C. japonica, and 14 L for L. indica. A tree with the diameter size of 10 cm annually offset carbon emissions from gasoline use of approximately 8 L for Q. myrsinaefolia, 5 L for C. japonica, and 2 L for L. indica. The study pioneers in quantifying biomass and carbon reduction for the landscape tree species in the southern region despite difficulties in direct cutting and root digging of the planted trees.

• Journal of the Korean Society of Clothing and Textiles
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• v.28 no.12 s.138
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• pp.1596-1604
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• 2004

Quality Function Deployment(QFD) is a product development tool which ensures that the voice of the customer needs is heard and translated into products. To develop a sensible brassiere for middle-aged women QFD was adopted. In this study the applicability and usefulness of QFD was examined through the engineering design process for a sensible brassiere for middle-aged women. The customer needs for the wear comfort of brassiere was made by one-on-one survey of 100 women who aged 30-40. The customer competitive assessment was generated by wearing tests of 10 commercial brassieres. The subjective assessment was conducted in the enviornmental chamber that was controlled at $28{\pm}1^{\circ}C,\;65{\pm}3\%RH.$ As a results, we developed twenty-one customer needs and corresponding HOWs for the wear comfort of brassiere. The Customer Competitive Assessment was generated by wearing tests of commercial brassiere. The subjective measurement scale and dimension for the evaluation of sensible brassiere were extracted from factor analysis. Four factors were fitting, aesthetic property, pressure sensation, displacement of brassiere due to movement. The most critical design parameter was wire-related property and second one was stretchability of main material of brassiere. Also, wearing comfort of brassiere was affected by the interaction of initial stretchability of wing and support of strap. Engineering design process, QFD was applicable to the development of technical and aesthetic brassieres.