• Journal of Environmental Impact Assessment
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• v.24 no.5
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• pp.444-455
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• 2015

In relation to the utilization and disposal of dredged sediment caused by coastal dredging project, we diagnosed the status of legal standard and system, and proposed the improvement plan. Dredging costal sediment distinguished the usage and the disposal by the Standard for the Beneficial Usage of Dredged Sediment. The site where disposal has been completed could be used as a site for developmental project. In case of the usage of dredged sediment for reclamation, we found that the adaptation of the Standard for Beneficial Usage of Dredged Sediment is appropriate for reclamation considering the characteristic of soil, the differences of variables, and the distinction of standard analysis methods. The current the Standard for Beneficial Usage of Dredged Sediment requires the improvement with the usage of dredging coastal sediment in the following. First, the Standard needs to include the standard of the discrimination for reclamation. Second, the current Standard is necessary to be divided by two levels, it needs to be mitigated considering human health risk. Third, it is necessary to consider both the marine environmental impact assessment and mitigation plan near coastal dredging area.

• Journal of Elementary Mathematics Education in Korea
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• v.13 no.1
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• pp.1-15
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• 2009

This research is to provide a useful reference for the future revision of textbook by comparative analysis with the textbook in the 4th grade of elementary school in Japan. The results from this research is same as follows: First, Korean curriculum is emphasizing the reasonable problem-solving ability developed on the base of the mathematical knowledge and skill. Meantime, Japanese puts much value on the is focusing on discretion and the capability in life so that they emphasize each person's learning and raising the power of self-learning and thinking. The ratio on mathematics in both company are high, but Japanese ensures much more hours than Korean. Second, the chapter of Korean textbook is composed of 8 units and the title of the chapter is shown as key word, then the next objects are describes as 'Shall we do$\sim$' type. Hence, the chapter composition of Japanese textbook is different among the chapter and the title of the chapter is described as 'Let's do$\sim$'. Moreover, Korean textbook is arranged focusing on present study, however Japanese is composed with each independent segments in the present study subject to the study contents. Third, Japanese makes students understand the decimal as the extension of the decimal system with measuring unit($\ell$, km, kg) then, learn the operation by algorithm. In Korea, students learn fraction earlier than decimal, but, in Japan students learn decimal earlier than fraction. For the diagram, in Korea, making angle with vertex and side comes after the concept of angle, vertex and side is explained. Hence, in Japan, they show side and vertex to present angle.

• Journal of Chest Surgery
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• v.26 no.7
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• pp.513-520
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• 1993

Surgical treatment of aneurysm or dissection involving the ascending aorta and aortic arch still poses one of the most complicated technical and tactical challenges in surgery. The use of total circulatory arrest[TCA] with profound hypothermia in the surgical treatment of aneurysmal dissection involving the ascending aorta and aortic arch has been reported as popular surgical methods. However, the safe period of prolonged circulatory arrest with hypothermia remains controversial and ischemic damage to the central nervous system and uncontrollable perioperative bleeding have been the major problem. We have found profound hypothermic circulatory arrest with retrograde cerebral perfusion via the superior vena cava to achieve cerebral protection. We experiment the aortic anastomosis in 7 adult mongrel dogs, using profound hypothermic circulatory arrest with continuous retrograde cerebral perfusion[RGCP] via superior vena cava. We also studied the extent of cerebral protection using above surgical methods, by gas analysis of retrograde cerebral perfusion blood and returned blood of aortic arch, preoperative, intraoperative and postoperative electroencephalography and microscopic findings of brain tissue. The results were as follows: 1. The cooling time ranged from 15 minutes to 24 minutes[19.71$\pm$ 3.20 minutes] ; Aorta cross clamp time ranged from 70 minutes to 89 minutes[79.86 $\pm$ 7.54 minutes] ; Rewarming time ranged from 35 minutes to 47 minutes[42.86$\pm$ 4.30 minutes] ; The extracorporeal circulation time ranged from 118 minutes to 140 minutes[128.43$\pm$ 8.98 minutes] [Table 2]. 2. The oxygen content in the oxygenated blood after RGCP was 12.66$\pm$ 1.25 ml/dl. At 5 minutes after the initiation of RGCP, the oxygen content of returnedlood was 7.58$\pm$ 0.21 ml/dl, and at 15 minutes 7.35$\pm$ 0.17 ml/dl, at 30 minutes 7.20$\pm$ 0.19 ml/dl, at 60 minutes 6.63$\pm$ 0.14 ml/dl [Table 3]. 3. Intraoperative electroencephalographic finding revealed low amplitude potential during hypothermia, and no electrical impulse throughout the period of circulatory arrest and RGCP. Electrical activity appeared after reperfusion, and the electroencephalographic reading also recovered rapidly as body temperature returned to normal [Fig. 2]. 4. The microscopic finding of brain tissue showed widening of the interfibrillar spaces. But there was no evidence of tissue necrosis or hemorrhage [Fig. 3]. We concluded the retrograde cerebral perfusion during hypothermic circulatory arrest is a simplified technique that may have a excellent brain protection.

• Journal of the Korean Society for Nondestructive Testing
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• v.26 no.2
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• pp.90-98
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• 2006

Signals captured from a Combo calibration standard tube paly a crucial role in the evaluation of motorized rotating pancake coil (MRPC) probe signals from steam generator (SG) tubes in nuclear power plants (NPPs). Therefore, the Combo tube signals should be consistent and accurate. However, MRPC probe signals are very easily affected by various factors around the tubes so that they can be distorted in their amplitudes and phase angles which are the values specifically used in the evaluation. To overcome this problem, in this study, we explored possibility of simulation to be used as a practical calibration tool far the evaluation of real field signals. For this purpose, we investigated the characteristics of a MRPC probe and a Combo tube. And then using commercial software (VIC-3D) we simulated a set of calibration signals and compared to the experimental signals. From this comparison, we verified the accuracy of the simulated signals. Finally, we evaluated two defects using the simulated Combo tube signals, and the results were compared with those obtained using the actual field calibration signals.

• Journal for History of Mathematics
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• v.25 no.1
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• pp.71-88
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• 2012

The purpose of this study is to find the way to build the concept image about natural logarithm and the method is using definite integral in calculus under GeoGebra environment. When the students approach to natural logarithm, need to use dynamic program about the definite integral in calculus. Visible reasoning process through using dynamic program(GeoGebra) is the most important part that make the concept image to students. Also, for understand mathematical concept to students, using GeoGebra environment in dynamic program is not only useful but helpful method of teaching and studying. In this article, about graph of natural logarithm using the definite integral, to explore process of understand and to find special feature under GeoGebra environment. And it was obtained from a survey of undergraduate students of mathmatics. Also, relate to this process, examine an aspect of students, how understand about connection between natural logarithm and the definite integral, definition of natural logarithm and mathematical link of e. As a result, we found that undergraduate students of mathmatics can understand clearly more about the graph of natural logarithm using the definite integral when using GeoGebra environment. Futhermore, in process of handling the dynamic program that provide opportunity that to observe and analysis about process for problem solving and real concept of mathematics.

• Health Policy and Management
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• v.5 no.1
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• pp.31-58
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• 1995

The Korean government achieved the universal coverage of health insurance in July 1989, and concomitantly introduced a new measure of regulated health care delivery system in using medical care. There are three reasons why the government took the new health care delivery system. Firstly, there was ample room for improving the allocative efficiency in the use of medical facilities. And the second one was to constrain the dramatic increase of medical demand under health insurance. Thirdly, and the most important reason was to alleviate the patient crowdedness in big general hospitals, particularly tertiary hospitals. There are essentially two different ways to control the use of health care : one is to cut the demand for health care, and the other to regulate behaviors of providers through the use of incentives/disincentives, demand-side approach or supply-side approach. The objective of this study is to examine whether or not medical care utilization behaviors under health insurance scheme have been changed among medical facilities such as clinic, hospital, general hospital and tertiary hospital in comparison with those before and after the introduction, particularly whether the patient crowdedness in tertiary hospitals has been alleviated or not. In order to conduct this study, the insurance claim data during the period of January 1989 and July 1992 were analyzed by focusing on diagnosis of both inpatients and outpatients, and especially the fifteen most frequent diseases in ambulatory care and the seven most frequent diseases in hospitalizatio. In addition, the same analyses were made on the changes in medical care utilization by specialty department. This was because the five departments, such as family medicine, ENT, eye, dermatology and rehabilitation, were exempted from applying the regulated health care delivery system in tertiary hospitals. The study revealed that a remarkable alleviation effect in the crowdness was noted for tertiary hospitals. This effect was most conspicuous for the most frequent mild diseases of both inpatient and outpatient care. For example, the fifteen most frequent OPD care at tertiary facilities have decreased as much as by 40%, of which 34% belonged to the cut in initial visits. Meanwhile, the proportion of those who used general hospitals and private practitioner's clinics have increased due to the shift of patients. The cases from the five special departments were also decreased, but not so much as other departments. A problem was noted that, as time passed by, the decreasing tendencies of crowdness at tertiary hospitals due to the regulated system became slightly smaller. Therefore, through complementary remedies are needed for the future implementation.

• Journal of the Korean Society for Heat Treatment
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• v.25 no.1
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• pp.6-13
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• 2012

HVOF thermal spray coating of 80%WC-CoFe powder is one of the most promising candidate for the replacement of the traditional hard chrome plating and hard ceramics coating because of the environmental problem of the very toxic $Cr^{6+}$ known as carcinogen by chrome plating and the brittleness of ceramics coatings. 80%WC-CoFe powder was coated by HVOF thermal spraying for the study of durability improvement of the high speed spindle such as air bearing spindle. The coating procedure was designed by the Taguchi program, including 4 parameters of hydrogen and oxygen flow rates, powder feed rate and spray distance. The surface properties of the 80%WC-CoFe powder coating were investigated roughness, hardness and porosity. The optimal condition for thermal spray has been ensured by the relationship between the spary parameters and the hardness of the coatings. The optimal coating process obtained by Taguchi program is the process of oxygen flow rate 34 FRM, hydrogen flow rate 57 FRM, powder feed rate 35 g/min and spray distance 8 inch. The coating cross-sectional structure was observed scanning electron microscope before chemical etching. Estimation of coating porosity was performed using metallugical image analysis. The Friction and wear behaviors of HVOF WC-CoFe coating prepared by OCP are investigated by reciprocating sliding wear test at $25^{\circ}C$ and $450^{\circ}C$. Friction coefficients (FC) of coating decreases as sliding surface temperature increases from $25^{\circ}C$ to $450^{\circ}C$.

• Journal of Educational Research in Mathematics
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• v.17 no.2
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• pp.179-199
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• 2007

The purpose of this study was to discover differences between mathematically gifted students (MGS) and non-gifted students (NGS) when making probability judgments. For this purpose, the following research questions were selected: 1. How do MGS differ from NGS when making probability judgments(answer correctness, answer confidence)? 2. When tackling probability problems, what effect do differences in probability judgment factors have? To solve these research questions, this study employed a survey and interview type investigation. A probability test program was developed to investigate the first research question, and the second research question was addressed by interviews regarding the Program. Analysis of collected data revealed the following results. First, both MGS and NGS justified their answers using six probability judgment factors: mathematical knowledge, use of logical reasoning, experience, phenomenon of chance, intuition, and problem understanding ability. Second, MGS produced more correct answers than NGS, and MGS also had higher confidence that answers were right. Third, in case of MGS, mathematical knowledge and logical reasoning usage were the main factors of probability judgment, but the main factors for NGS were use of logical reasoning, phenomenon of chance and intuition. From findings the following conclusions were obtained. First, MGS employ different factors from NGS when making probability judgments. This suggests that MGS may be more intellectual than NGS, because MGS could easily adopt probability subject matter, something not learnt until later in school, into their mathematical schemata. Second, probability learning could be taught earlier than the current elementary curriculum requires. Lastly, NGS need reassurance from educators that they can understand and accumulate mathematical reasoning.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.6
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• pp.2819-2827
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• 2013

The purpose of his study was to analyze the environmental and the medical factors of prematurely discharged patients in a rehabilitation hospital. The subjects were 107 inpatients. The data were collected using self-report questionnaire and analyzed using the SPSS Win 19.0 program. In result, Firstly, general selection of hospitals was the 'Recommendation' 35.5%, Environmental dissatisfaction factors are Hospital facilities 37.4%. Hospital choice is the highest 'Acquaintances' 23.4%. Second, the lowest group about professionalism, kindness, and description of explanation on satisfaction in survey is group of care workers for the sick. The highest group is physical and occupational therapist. Third, the satisfaction regarding medical procedures of administrative work, waiting time and medical expenses is the highest normal. Hospital facilities in one of the highest factors in environmental dissatisfaction is can be considered as an element of patient departure because of not much number of nervous special hospitals. Medical dissatisfaction factors is the lowest satisfaction of care worker even if those spend much time. this is the focus leaving hospital. Therefore, factors care workers on service satisfaction and dissatisfaction in analysis and problem solving is considered that the need to find ways to improve the quality of service care workers.

• Korean Journal of Medicinal Crop Science
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• v.21 no.5
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• pp.380-387
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• 2013

This study was carried out to investigate the difference of the content of soil chemical components and growth characteristics in five years old ginseng affected by application of manure in paddy-converted field. As all livestock manure regardless of kinds increased along with the whole soil chemical component, including the pH and EC in 2008. Change in the EC of control plot was slightly increased but not exceeded 1 ds/m over the years. However, the changes in the EC of livestock manure regardless of kinds and amounts were highly increased and irregularly exceeded 1.5 ds/m in 2012. The 5 years old ginseng root fresh weight, treatment of fertilizing pig manure compost 4 ton per 10 areas (PMC 4t on/10a) and fowl manure compost 4 ton per 10 areas (FMC 4 ton/10a), were superior to the others. But there were no difference between PMC 4 ton/10a, FMC 4 ton/10a and control. The standing crop rate 39.6%, treatment of fertilizing cattle manure compost 4 ton per 10 areas (CMC 4 ton/10a), was best in all livestock manure. However that was relatively lower than control. Physiological disorder occurrence rates of livestock manure related with leaf and root of ginseng were also higher than that of control. If excessively using non-decomposed livestock manure, It would be caused physiological disorder in many ways. It is a big problem to be producing the quality ginseng. More research is needed to find out the economic and effective fertilizer.