• Environmental and Resource Economics Review
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• v.24 no.4
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• pp.629-655
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• 2015

Nuclear power generation is a major power source which accounts for more than 30% of domestic electricity generation. Electricity market needs to secure stability of base load. This study aimed at analyzing relationships between nuclear power generation and wholesale electricity price (SMP: System Marginal Price) in Korea. For this we conducted ARDL(Autoregressive Distributed Lag) approach and Granger causality test. We found that in terms of total effects nuclear power supply had a positive relationship with SMP while nuclear capacity had a negative relationship with SMP. There is a unidirectional Granger causality from nuclear power supply to SMP while the reverse was not. Nuclear power is closely related to SMP and provides useful information for decision making.

• Journal of Labour Economics
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• v.29 no.2
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• pp.67-116
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• 2006

This study directly analyzes the wage distributions rather than indirectly looking at a few of their moments. It also investigates wage distributions using various descriptive and semi-parametric methods. The wage distributions of Korean manufacturing industries can in general be represented by three distinct forms, underdeveloped, advanced and the medium of the two. The discrepancies in these distribution forms are explained by differences in the labor-type distributions and their weights in the composition of wage distribution forms, and further clarified through various descriptive statistics based on them. However, the descriptive statistical analysis has a limit in that it shows mixed outcomes of different categoric variables. Then, this problem is resolved by applying a semi-parametric estimation of hazard function and the marginal effect evaluations of variable changes on estimated distributions not on the function. As a result of this marginal analysis, the common features and differences of categoric variables and their intensities of effects on distributions are revealed.

• Journal of Labour Economics
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• v.43 no.1
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• pp.59-91
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• 2020

The recent reform of child care policy is to give priority to double-income households in the use of childcare facilities. This study analyzed the effect of the use of childcare facilities on the employment of married women under the on-going reform. Using the data from the 19th and 21st wave of the Korean Labor and Income Study, the marginal treatment effect (MTE) analysis method was used to eliminate the selection bias in which the sub-population targeted for policy is determined according to the priority when childcare demand exceeds supply. The study finds that the employment effect of married women who use childcare facilities does not differ statistically from the employment effect of married women who do not use childcare facilities.

• Journal of Periodontal and Implant Science
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• v.45 no.3
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• pp.82-93
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• 2015

Purpose: This retrospective study evaluated the relationship between the timing of peri-implantitis diagnosis and marginal bone level after a 5-year follow-up of non-surgical peri-implantitis treatment. Methods: Thirty-three patients (69 implants) were given peri-implantitis diagnosis in 2008-2009 in Seoul National University Bundang Hospital. Among them, 31 implants from 16 patients were included in this study. They were treated non-surgically in this hospital, and came for regular maintenance visits for at least 5 years after peri-implantitis treatment. Radiographic marginal bone levels at each interval were measured and statistical analysis was performed. Results: Timing of peri-implantitis was one of the significant factors affecting initial bone loss and total bone loss not additional bone after peri-implantitis diagnosis. Patients with cardiovascular disease and diabetic mellitus were positively influenced on both initial bone loss and total bone loss. Patients who needed periodontal treatment after implant placement showed a negative effect on bone loss compared to those who needed periodontal treatment before implant placement during entire periods. Implant location also significantly influenced on amounts of bone loss. Mandibular implants showed less bone loss than maxillary implants. Among surgical factors, combined use of autogenous and xenogenic bone graft materials showed a negative effect on bone loss compared to autogenous bone graft materials. Use of membrane negatively affected on initial bone loss but positively on additional bone loss and total bone loss. Thread exposure showed positive effects on initial bone loss and total bone loss. Conclusions: Early peri-implantitis diagnosis led to early non-surgical intervention for peri-implantitis treatment, which resulted in the maintenance of the bone level as well as preservation of the implant.

• The Journal of Dong Guk Oriental Medicine
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• v.5
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• pp.197-207
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• 1996

As a mood-altering drug, long-term alcohol consumption have significant harmful effects on the human body and people's mental functioning. This study observed that the suppression of cell mediated immunity induced in spleen of ICR mouse by long-term alcohol administration. After 8% alcohol voluntary administered for 120 days, the splenic tissue irnmunohistochemically stained by following ABC method that used monoclonal antibody including L3T4(CD4), Ly-2(CD8), IL-2 receptor(CD25R) and NK-1.1(CD56) after embedding with paraffin. The results were as follows. 1. The size of marginal zone in splenic white pulp was diminished and the number of macrophage in marginal zone was decreased in test group than control group. 2. After alcohol administration, the number of Helper T lymphocyte, cytotoxic T lymphocyte, and IL-2 receptor were decreased in periarterial lymphatic sheaths of white pulp and penicilla artery of red pulp and the degree of CD4, CD8, and CD25R positive reaction were soften. 3. In test group, the number of NK cell were decreased. These results indicated that the secretion of lymphokine as IL-2 was inhibited by long-term alcohol administration and subsequently prevent to activate and proliferate splenic T lymphocytes and NK cells as cell mediated immunity component.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.3
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• pp.342-350
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• 2003

Statement of problem. Titanium-Nickel alloy might be used in various prosthetic restorations since it has a unique property such as super-elasticity and high fatigue resistance. However, little is known about the casting ability of this alloy. Purpose. This in vitro study compared the casting accuracy and the porosity made with different investments and various sprue designs to ascertain what casting condition would be better for the fabrication of Ti-Ni cast restorations. Material and methods. A total of 70 Ti-Ni alloy crowns were made and divided into 7 groups of 10 copings on a metal master die. For measuring the effect of the sprue numbers, two groups with one and two 8-gauge sprues were compared. Moreover, the results of the conventional sprue and the double thickness sprues were compared. Three investments were used; carbon free phosphate bonded investment, titanium investment and gypsum bonded investment. The cast restorations were evaluated at 48 points on the entire circumferential margin with a stereomicroscope measuring in micrometers. Each crown was radiographically examined for casting defects and porosity. Data on casting accuracy were analyzed using two-way and Post hoc Scheffe's comparison to determine whether significant differences existed at the 95% confidence level. Student-Newman-Keuls test were performed to identify significant differences in the number of voids. Results. The double sprueing group and double thickness group had significantly less marginal discrepancy than the single sprueing group (P<.05 and P<.01, respectively). The castings with phosphate bonded investment showed the least marginal discrepancy and the smoothest surface. The castings invested in the gypsum bonded investment had the greatest gaps in margin and the largest failure rate. The double sprueing group and phosphate bonded investment group had significantly smaller void numbers and smaller void size than the other groups. Conclusion. Within the limitations of this in vitro study, the casting accuracy of the groups using thicker, double sprue design and the phosphate bonded investment was significantly superior. Moreover, void number and size were less than other groups.

• Journal of Periodontal and Implant Science
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• v.52 no.3
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• pp.194-205
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• 2022

Purpose: This study aimed to determine the long-term outcomes after peri-implantitis treatment and the factors affecting these outcomes. Methods: This study included 92 implants in 45 patients who had been treated for peri-implantitis. Clinical data on the characteristics of patients and their implants were collected retrospectively. The change in the marginal bone level was calculated by comparing the baseline and the most recently obtained (≥3 years after treatment) radiographs. The primary outcome variable was progression of the disease after the treatment at the implant level, which was defined as further bone loss of >1.0 mm or implant removal. A 2-level binary logistic regression analysis was used to identify the effects of possible factors on the primary outcome. Results: The mean age of the patients was 58.7 years (range, 22-79 years). Progression of peri-implantitis was observed in 64.4% of patients and 63.0% of implants during an observation period of 6.4±2.7 years (mean±standard deviation). Multivariable regression analysis revealed that full compliance to recall visits (P=0.019), smoking (P=0.023), placement of 4 or more implants (P=0.022), and marginal bone loss ≥4 mm at baseline (P=0.027) significantly influenced the treatment outcome. Conclusions: The long-term results of peri-implantitis treatment can be improved by full compliance on the part of patients, whereas it is impaired by smoking, placement of multiple implants, and severe bone loss at baseline. Encouraging patients to stop smoking and to receive supportive care is recommended before treatment.

• Journal of Technology Innovation
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• v.20 no.3
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• pp.57-91
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• 2012

This paper investigates determinants of litigation success in the two distinctive types of patent litigations, ex-parte and inter-parte cases, which are brought in the process where a filed application becomes a valid patent right. We regress winning rates of patent applicants on the characteristics of firms, trials, patent lawyer, and patent itself, using a probit model with sample selections. The paper finds that the relative suit rate of a firm, time to be sued, changes of patent agents by applicants, and multiple agents among explanatory variables affect ex-parte reexamination and in-parte post-grant patent trials differently in the point of average marginal effects. These variables lower the probability of applicant's victory in the ex-parte cases, while they raise the probability in the inter-parte trials. However, the experience that agents represent applicants is a winning rate-increasing factor both in inter-parte and ex-parte reexamination, unexpectedly. This result cannot be applied to the entire domain of the variable, since sample selection effects are reflected in the result. The number of claim increases the winning probability of the applicant in the both types of patent litigations. This study has some limitations because it ignores the information on the legal person to which a patent agent belongs, and confined agent's experience to patent filing. We leave it future studies to investigate the effects of lawsuit experience of patent agent, and those of characteristics of the law firm to which individual patent lawyer is affiliated.

• Communications for Statistical Applications and Methods
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• v.24 no.3
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• pp.291-301
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• 2017

It is well known in a small sample that the maximum likelihood (ML) approach for variance components in the general linear model yields estimates that are biased downward. The ML estimate of residual variance tends to be downwardly biased. The underestimation of residual variance, which has implications for the estimation of marginal effects and asymptotic standard error of estimates, seems to be more serious in some limited dependent variable models, as shown by some researchers. An alternative frequentist's approach may be restricted or residual maximum likelihood (REML), which accounts for the loss in degrees of freedom and gives an unbiased estimate of residual variance. In this situation, the REML estimator is derived in a censored regression model. A small sample the REML is shown to provide proper inference on regression coefficients.

• Journal of the Korean Society of Costume
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• v.28
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• pp.85-98
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• 1996

Yanbian is the area where many Korean-Chinese have settled and have undergone a unique culture. This study is intended to examine the clothing life of Korean-Chinese in Yanbian in the aspects of the cultural marginality and the effects of other cultures. Nowadays they have three kinds of dresses" Han-Bok In-Min-Bok and the western dress. han-Bok is the result of cultural marginal phenomenon so they pre-serve 1920s style which already disappeared in South Korea. In-Min-Bok is the production of Communism which is an 'invention' from the viewpoint of Cultural-Anthropology. However both Han-Bok and In-Min-Bok are gradually disappearing from the daily life. Today it is quite common for us to see a number of people wearing western dresses on the street. In their clothing life the acculturation to the Chinese wasn't traced which may be due to the strong 'National I dentity' of them.