• Journal of the Korean BIBLIA Society for library and Information Science
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• v.28 no.4
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• pp.321-340
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• 2017

The purpose of this study is to design a teaching model applying a problem-based learning model and to analyze the educational benefits that students felt. This study initiated a problem-based learning model from an analysis of existing studies. Through the consultation of experts, the scenario was modified. The problem was designed according to the design stage activity (problem analysis, PBL class suitability judgment, contents analysis, learner analysis, environment analysis, PBL operating environment decision, PBL class) and Strategic Design (problem situation design, learning resource design, Facilitation design, operational strategy design, evaluation design, PBL operating environment design). Based on the initial scenarios, the researcher analyzed the results of the problem - based learning through learners' reflective diaries. The researcher was able to confirm that the critical thinking and creativity were improved in the first PBL problem situation, and the method for smooth communication and cooperation was utilized. The results on analyzing the effects of education about the first problem-based learning and students' opinions about modification will be used for the second revision and supplement of the course design. This study introduces a case of PBL course development and expects further application and research.

• Transactions of the KSME C: Technology and Education
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• v.5 no.2
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• pp.135-143
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• 2017

The domestic unique research reactor, HANARO (Hi-flux Advanced Neutron Application ReactOr), has been constructed with the open-pool, the core is submerged in, for the multi-purpose neutron application. The reactor has a primary cooling system to remove the fission heat from the core and its connected fluidic systems. Since the works are required at the reactor pool top as a characteristic of the research reactor, the radiation shall be minimized with the operation of the hot water layer system to avoid unnecessary radiation exposure on the workers during work at the pool top. Moreover, the pool water management system is connected to the reactor pool to maintain the pool temperature below $50^{\circ}C$ to minimize the uprising radioactive gas or impurity from the colder pool bottom. For the efficient flow rate of the PWMS, the thermal capacity of heat exchanger is selected with 260 kW in the normal operation condition. In this paper, the modeling is formulated to figure out whether or not each pool temperature maintains below the temperature limit and the calculation results show that the designed PWMS heat exchanger has enough capacity with the design margin regardless of the reactor operation mode.

• The Journal of Engineering Geology
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• v.16 no.4 s.50
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• pp.403-409
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• 2006

This study was performed to assess the clay impact on alga growth which was a primary producer, in view of food chain in ecosystem. As clay minerals caused turbidity, a low sedimentation, high adsorption capacity with organic matter, adsorption - desorption effect with ionic chemicals, clay minerals were supposed to have a significant effect on the aquatic system. In study we tried to turn out NOAEL (No-observed-adverse-effect-level) of clay materials on the algae growth inhibition using such as kaolinite, sericite and montmorillonite. This study was indicated. (1) In both of kaolinite and sericite, the $72hr-EC_{50}$ of them shows 2,752 mg/L and 2,775 mg/L, respectively. (2) On the other hand, in the case of montmorillonite, the $72hr-EC_{50}$ is not shown a significant difference to that of control samples. (3) It can be explained that is also a very important parameter in an alga growth. Because an alga growth was increased when the permeability of W visible radiation was increased in all clay cases. (4) It is demonstrated alga growth was affected by the characteristics of clay materials. Hence we can assess the $\ulcorner$water environmental risk assessment caused clay materials$\lrcorner$ using the alga growth inhibition level indirectly.

• The Journal of Engineering Geology
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• v.25 no.4
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• pp.499-510
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• 2015

Artificial accelerated weathering test evaluated rocks from near the circuit road of Ulleungdo island, approximately 120 km from east of the Korean Peninsula. The tests subjected rock specimens to conditions based on the climate of the island. The specimens (such as basaltic breccia, trachyte, volcanic breccia) were preliminarily classified using a TAS diagram (XRF data) and based on the constituent minerals (XRD data); they were further classified by weathering degree according to their absorption ratios. During the artificial accelerated weathering, the absorption ratio of most of the specimens increased, but the point-load strength did not decrease in most cases, except for the volcanic breccia. The greater initial absorption ratio of trachyte rock specimen in comparison with the other specimens led to a greater increase of its absorption ratio during the artificial accelerated weathering test. The volcanic breccia specimens showed the greatest increase of absorption ratio and the biggest reduction ratio of the point- load strength during the tests. These results could aid prediction of the weathering rate of rocks in Ulleungdo island subjected to weathering processes; trachyte which appears to accelerate with time, and volcanic breccia whose mechanical strength can largely decrease in a relative short period of time. Proper measures therefore appear necessary for the prevention of natural disaster such as rock fall and landslide around the circuit road.

• Clinics in Shoulder and Elbow
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• v.10 no.2
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• pp.190-198
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• 2007

Purpose: The current study reports the clinical results of total elbow arthroplasties (TEA) which were Performed on patients with poor clinical and radiological results after initial surgeries for elbow fractures or dislocations. Materials and Methods: The clinical outcomes of twelve consecutive patients who underwent TEA after failed surgeries for elbow fractures or dislocations from january, 1995 to December, 2005 were evaluated. The initial diagnoses were distal humeral fractures in 8 cases and fracture-dislocations in 4 cases. The Mean period from the initial operations to the TEAs was 12 months. The mean folloow up period after TEA was 43 months. Results: The mean range of motion, in terms of active extension, activeflexion, supination, and pronation, improved from $14.2^{\circ}$, $96.7^{\circ}$, $50.8^{\circ}$ and $53.3^{\circ}$ to $5.4^{\circ}$, $122.1^{\circ}$, $63.3^{\circ}$ and $67.5^{\circ}$, respectively (p<0.05). RAdiolucent lines were found in 3 cases, which were 1 case of type 3, and 2 cases of type 4. All three loosening cases underwent revision TEAs. The mean postoperative Mayo elvow performance score was 79 point. There were 6 cases of excellent, 2 cases of good, and 4 cases in poor. Conclusion: Good clinical results were obtained after TEA performed in failed surgeries for elbow fractures of dislocations.

• Archives of design research
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• v.12 no.2
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• pp.133-144
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• 1999

Considering product as mass of information, it is very critical for designers to have good means of accessing to and organizing information on products. However, designers conventionally depend on their experience, bunch of catalogues, or short visit to some fairs for gathering information on products. There are no systematically organized information for designing new products. If any, those are ones developed by market researchers or engineers who speak fundamentally different language from designers. It is needed to develop the information system through which designer can get insights on the essence of product and communicate information with various persons involved in new product planning. At first, the design information in product planning is discussed and the necessity of development of new design information system is emphasized. Then, product is understood as a composite of various attributes and a set of fundamental attributes of product is defined by surveying and summarizing existing theories of product attributes: namely technological, human, and market attributes. The possibility of new design information system is explored by analyzing various relationships between attributes of different products. Computer program 'DISPP' displays various visual information of product itself, perceptual map, trend slope, profile chart and general information of manufacturer, style, color, price, size. Finally, findings of thesis are concluded and further prospects of the study are proposed.

• Journal of Chest Surgery
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• v.30 no.6
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• pp.585-590
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• 1997

Between December 1994 and October 1996, 57 premature infants with evidence of a hemodynamically significant PDA associated with cardiopulmonary compromise underwent indomethcin therapy(Group I, n=48) or surgical ligation(Group II, n=9) because of indomethacin failure. The gestational alee(29.6$\pm$ 3.1weeks vs. 28.1 $\pm$ 1.6weeks) and birth weight(1,413 $\pm$ 580gm, ,098 $\pm$ 235gm) showed no significant differences between the two groups. Medical management included fluid restriction, diuretics, and indomethacin therapy(one or two cycles). Surgical libation was done at the neonatal intensive care unit(NICU) without moving the patient to the operation room. There was no complication associated with the operation. There were 9 deaths in Group I(19%, 9/48) and 2 deaths in Group II(22% , 219). The main causes of deaths were persistent bronchopulmonary dysplasia with sepsis(n=8) and intrapulmonary hemorrhage(n=3). The rate of medical treatment failure including death and complication in premature infants whose body weights were less than 1500gm was higher(41%, 15/38) than in premature infants whose body weights were more than 1500gm(16%, 3/19). Early surgical ligation of PDA may be applicable in the premature infant with a large size, low birth weight(<1500 gm), or associated intracardiac anomalies. Perfoming the operation in the NICU may be safe in s ead of moving the patient to the operating room.

• Journal of Chest Surgery
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• v.40 no.6 s.275
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• pp.455-458
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• 2007

A 40 year-old male patient admitted for dyspnea and edema of the lower extremities. A pulsatile abdominal mass with a bruit was palpable in the right lower quadrant. Four months previously, he had underwent left partial lam-inectomy ($L4{\sim}5$) and discectomy at the L4 level due to disc protrusion, Computed tomography showed an ilio-iliac AV fistula with pseudoaneurysm at the L5 level. Because massive bleeding occurred when the aneurysm was entered, we closed the aneurysm and performed resection and suture of the aorta and both iliac arteries very near the aneurysm. After exclusion of the arterial side, we performed reduction angioplasty at the aneurysm and aorto-biiliac reconstruction with an artifcial graft. Twenty-four months after operation, he is doing well and hasn't had any complications on the follow-up.

• Journal of the Korean Society of Radiology
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• v.10 no.3
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• pp.187-193
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• 2016

In this study, we performed the carotid artery ultrasound targeting 140 subjects who have conducted to evaluate the changes in intima-media thickness(IMT) and plaque correlated with the presence or absence of a hematological test of the carotid artery. Considering that the IMT thickness more than 1mm is abnormal based on the carotid artery ultrasound to assess the presence or absence of plaque, and examined the correlation by classifying the blood lipid value and the fasting blood glucose level through the serum test. Consequently, the fasting blood glucose level is being analyzed as independent predictors of causing dental plaque(p=0.033), cut off value was determined as 126 mg/dL(sensitivity 56.25%, specificity 68.38%) in ROC curve analysis. Furthermore, the odds ratio appeared 1.01 times the value in the Logistic regression. Therefore, it seemed that the necessity to prospective studies in a number of subjects are considered, and also taking into account a number of blood test values along with the sonography of the carotid artery as a valuable part for effective primary prevention and follow-up observation of the cardiac and brain vascular disease is highly recommended.

• Journal of the Korean Geotechnical Society
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• v.33 no.9
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• pp.5-22
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• 2017

The procedure that combines the result of infiltration analysis into stability analysis based on the limit equilibrium method is widely used to evaluate the impact of rainfall infiltration on slope stability. Accurate prediction of rainfall infiltration is essential to the prediction of landslides caused by rainfall, requires to obtain accurate unsaturated hydraulic properties of the soil. Among the unsaturated hydraulic characteristics of the soil, the importance of the soil-water characteristic curve describing the retained water characteristics of the soil is relatively well known and the measurement by test method to obtain the SWCC is gradually increasing. However, it takes a lot of time and expenses to experimentally measure the unsaturated conductivity characteristics of the soil. Therefore, it is common practice to estimate the hydraulic conductivity function from the SWCC. Although it is widely known that the SWCC has a great influence on rainfall infiltration, studies on the effect of the hydraulic conductivity function estimated from the SWCC on rainfall infiltration are very limited. In this study, we explained how the estimation model of the hydraulic conductivity function affects rainfall infiltration and slope stability analysis. To this end, one-dimensional infiltration analysis and slope stability analysis were conducted by using the data on the SWCC of weathered granite soil widely distributed in Korea. The applicability of each estimation model is discussed through review of the analysis results.