• 한국경영정보학회:학술대회논문집
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• 2007.06a
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• pp.395-400
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• 2007

Previous studies present the mixed results on online reputation mechanism. In this study, we have found that an approach based on Bayesian statistics can explain most results of previous studies which are conflicting with each others. With this model, we explain why negative ratings have more significant marginal impacts on sellers' reputation than positive ones do. Furthermore, we even show why the feedbacks with a few negative ratings may increase the value of the item and final prices by confirming buyers' prior beliefs on the sellers' reputation much more than those without negative ratings. Also, we explain why there are not many negative ratings. Even though some studies suggest this because of generosity of users, our model shows that the reason is that the existence of FS itself prevents bad sellers from participating to the market as a signal itself. Even further, we show how this extreme tendency of positive ratings gets even stronger as markets evolve. Finally, to validate our analytical results, we examine the previous studies and see what factors effect the outcomes of their analyses.

• The Journal of the Korean dental association
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• v.50 no.6
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• pp.304-311
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• 2012

Eruption of the teeth can be disturbed by crowding, ectopic eruption path, retention for pathologic condition of follicle and periodontal ligament, local disturbances in the innervation, and delayed eruption for overlying obstacles in the eruption path. Eruption disturbance of permanent posterior teeth is taken with diverse therapeutic approaches according to the patient age, cooperation of patient, tooth position and maturity, degree of impaction, clinical features, and repercussion on the neighboring teeth. However, delayed treatment usually results in less favorable outcomes. Therefore, In order to prevent this situation, periodically radiographic examinations during the early mixed dentition period and early diagnosis of eruption disturbances of permanent posterior teeth are recommended.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.05a
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• pp.128-129
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• 2015

Al-rich coatings were prepared on hot rolled low carbon steel by hot dipping method in molten Al-bath to investigate the corrosion resistance with the possible outcomes and defects of aluminized coatings in air and $Ar-0.2%SO_2$ mixed gases. Coating microstructure was composed of an inner Al-Fe intermetallic layer and outer Al-rich layer. Aluminum oxidized preferentially to the thin, outer, protective ${\alpha}-Al_2O_3$ layer, without forming the nonprotective iron/sulfur-oxide layer after heating at $800^{\circ}C$ for 20 h, in both the gases and provided the resistance against corrosion.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.05a
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• pp.122-122
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• 2015

Al-rich coatings were prepared on hot rolled low carbon steel by hot dipping method in molten Al-bath to investigate the corrosion resistance with the possible outcomes and defects of aluminized coatings in air and $Ar-0.2%SO_2$ mixed gases. Coating microstructure was composed of an inner Al-Fe intermetallic layer and outer Al-rich layer. Aluminum oxidized preferentially to the thin, outer, protective ${\alpha}-Al_2O_3$ layer, without forming the nonprotective iron/sulfur-oxide layer after heating at $800^{\circ}C$ for 20h, in both the gases and provided the resistance against corrosion.

• Journal of the Korea institute for structural maintenance and inspection
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• v.6 no.4
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• pp.91-98
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• 2002

Prediction for the compressive strength of concrete by non-destructive tests(NDT) has a tendency to show different outcomes according to various aggregates. The purpose of this study is to develop estimation equation by rebound number, ultrasonic velocity and combined method at concrete structures which used granite as coarse aggregates. The test variable is water/cement ratio(41.1%, 48.6%, 67.6%), curing method(moisture condition, dry condition) and age(7, 14, 28, 56). According to the test variable, new equation was suggested, and compared with the existing equations.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.791-795
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• 2005

A simulation model is proposed to evaluate the effect of correlations between activity durations on the overall project duration. The proposed model incorporates NORTA, a recent developed statistical method, into the simulation process to allow arbitrarily specified marginal distributions for activity durations and any desired correlation structure. The generality is of practical value when systematic data is not available and planners have to rely on arbitrary experts' estimation, which may involve a mixed situation when some activity durations are continuously distributed whereas others are discrete outcomes. The proposed model is validated by showing that the correlation coefficients of the simulation results are close to the originally specified ones. The simulation results are compared to two conventional approaches: PERT and simulation without correlation. The comparisons illustrate that the proposed model can provide important management information, which would otherwise be distorted due to the neglect of the correlations between activity durations.

• Journal of Korean Biological Nursing Science
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• v.25 no.4
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• pp.256-265
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• 2023

Purpose: This study examined the definitions, diagnostic criteria, and measurements of sarcopenic obesity and identified effective exercise interventions that improve cardiometabolic outcomes in middle-aged and older adults, in whom the prevalence of sarcopenic obesity is increasing. Methods: This comprehensive review followed the principles of literature search, data extraction, and review, as described in the PRISMA 2009 guidelines. Results: The 11 articles included in this study presented different concepts of sarcopenic obesity. Exercise interventions for sarcopenic obesity varied in their effects. Resistance exercise improved muscle mass and physical function, while aerobic exercise primarily impacted obesity and cardiometabolic indicators. Combined exercise had mixed results across indicators. Conclusion: This study addressed a pressing public health concern in the context of an aging population, acknowledged the unique challenges of sarcopenic obesity, and attempted to clarify definitions and assessment methods, while identifying effective exercise interventions to reduce cardiometabolic risk. Sarcopenic obesity is a multifaceted condition with varying definitions and diagnostic criteria. Its association with cardiometabolic risk underscores the need for comprehensive assessments considering both muscle and obesity indicators. While exercise interventions hold promise for managing sarcopenic obesity, further research is required to establish effective strategies.

• Journal of Korean Orthopaedic Sports Medicine
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• v.10 no.1
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• pp.18-26
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• 2011

Purpose: This study is to compare the clinical results of ACL reconstruction between three groups using hamstring tendon autograft, mixed and tibialis tendon allograft. Materials and Methods: Between August 2003 and August 2008, we analyzed 169 cases of ACL reconstruction, 66 cases used hamstring tendon autograft, 42 cases used mixed graft and 61 cases used tibialis tendon allograft, with a minimum follow-up of 12 months. For the clinical evaluation, we evaluated the Lysholm score, Telos stress test device and IKDC score. Results: The average side to side difference in Telos stress test decreased from $7.5{\pm}1.0$ mm to $1.6{\pm}1.0$ mm in autograft group, from $7.6{\pm}1.1$ mm to $1.4{\pm}1.1$ mm in mixed graft group and from $7.4{\pm}1.3$ mm to $2.5{\pm}1.3$ mm in allograft group. The average Lysholm knee score improved from 58.6 to 92.3 in autograft group, from 60.6 to 92.6 in mixed graft group and from 55.3 to 91.5 in allograft group. There was no significant difference between three groups in clinical results. At second look arthroscopy, tension of ligament and synovial coverage were good result in autograft and mixed graft than allograft group. Conclusion: All hamstring tendon autograft, mixed graft and tibialis tendon allograft groups showed satisfactory clinical results, with no significant difference in outcomes between the groups. Both hamstring tendon autograft and mixed graft showed good synovial coverage in second look arthroscopy. So mixed graft will be considered as good alternative in case of shorter or thin harvested hamstring tendon.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.5
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• pp.1935-1941
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• 2012

Introduction: Uterine sarcomas are a group of heterogenous and rare malignancies of the female genital tract and there is a lack of consensus on prognostic factors and optimal treatment. Objective and Methodology: To perform a retrospective evaluation of clinicopathological characteristics, prognostic factors and treatment outcomes of 93 patients with uterine sarcomas who were diagnosed and treated at 4 different centers from November 2000 to October 2010. Results: Of the 93 patients, 58.0% had leiomyosarcomas, 26.9% malignant mixed Mullerian tumors, 9.7% endometrial stromal sarcomas, and 5.4% other histological types. According to the last International Federation of Gynecology and Obstetrics (FIGO) staging, 43.0% were stage I, 20.4% were stage II, 22.6% were stage III and 14.0 % were stage IV. Median relapse free survival (RFS) was 20 months (95% confidence interval (CI), 12.4-27.6 months), RFS after 1, 2, 5 years were 66.6%, 44.1%, 16.5% respectively. Median overall survival (OS) was 56 months (95% CI, 22.5-89.5 months), and OS after 1, 2, 5 years was 84.7%, 78%, 49.4% respectively. Multivariate analysis showed that age ${\geq}60$ years and high grade tumor were significantly associated with poor OS and RFS; patients administered adjuvant treatment with sequential chemotherapy and radiotherapy had longer RFS time. Among patients with leiomyosarcoma, in addition to age and grade, adjuvant treatment with sequential chemotherapy and radiotherapy after surgery had significant effects on OS. Conclusion: Uterine sarcomas have poor progrosis even at early stages. Prognostic factors affecting OS were found to be age and grade.

• Journal of Science Education
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• v.45 no.2
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• pp.257-273
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• 2021

This study explores classes for pre-service mathematics teachers. The purpose of this study is to examine the differences between 'non-face-to-face' classes & 'face-to-face' classes, as well as the differences in learning outcomes between these two methods. A Professors' Learning Group was formed to effectively carry out this study. Through this learning group, we shared how to plan and operate the lecture. The subjects of this study are 'non-face-to-face calculus courses & face-to-face calculus courses' and 'non-face mathematics education theory courses & face-to-face mathematics education theory courses." Specifically, in these two pairs of courses, we analyze the differences in course management and the differences in the outcomes of students' assessments. Non-face-to-face classes were planned, developed, implemented and evaluated based on the 'non-face class design model.' The results of this study are as follows: First, we explored the differences between 'non-face-to-face classes/mixed classes' and 'face-to-face classes.' Second, the achievement results in calculus courses were higher in face-to-face classes than in non-face classes. Third, the results of achievements in mathematics education theory courses were higher in mixed classes than in face-to-face classes. Through the results of this study, we hope that the non-face-to-face class capabilities can be improved in pre-service mathematics teacher training.