• Communications for Statistical Applications and Methods
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• v.30 no.1
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• pp.49-63
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• 2023

A lot of studies on the summary measures of predictive strength of categorical response models consider the likelihood ratio index (LRI), also known as the McFadden-R², a better option than many other measures. We propose a simple modification of the LRI that adjusts for the effect of the number of response categories on the measure and that also rescales its values, mimicking an underlying latent measure. The modified measure is applicable to both binary and ordinal response models fitted by maximum likelihood. Results from simulation studies and a real data example on the olfactory perception of boar taint show that the proposed measure outperforms most of the widely used goodness-of-fit measures for binary and ordinal models. The proposed R² interestingly proves quite invariant to an increasing number of response categories of an ordinal model.

• Communications for Statistical Applications and Methods
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• v.15 no.4
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• pp.563-585
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• 2008

This paper presents how to improve the efficiency and accuracy in the pricing and sensitivity evaluation for derivatives, since the need for the evaluation of complicated derivatives is increased. The Monte Carlo(MC) simulation using the quasi random number instead of pseudo random number can improve the elapsed time and accuracy for the valuation of European-type derivatives. However, the quasi MC simulation method has its limit for applying it in the multi-dimensional case such as American-type and path-dependent options due to the increased correlation between dimensions as the dimension of random numbers is increased. In order to complement this problem, we develop a modified method in which correlation values are controlled to be below a pre-specified value. Thus, this method is applicable for the pricing of either derivatives ill which underlying assets or risk factors are several or derivatives having path-dependent or early redemption property. Furthermore, we illustrate that it is important to take an appropriate grid interval for the use of finite difference method(FDM) by applying the FDM to one example of non-symmetrical butterfly spreads.

• Nuclear Engineering and Technology
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• v.27 no.1
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• pp.33-44
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• 1995

Public acceptance has become an important factor in nuclear power program particularly after Chernobyl accident and recent rapid democratization in Korea. Methods reflecting public opinions in order to improve public acceptance are firstly to understand what the public think about nuclear power plant and secondly to find out the public preference values for its policies. For this purpose, simplified multi-attribute utility (MAU) model was applied to analyze the public perception pattern for fire power production systems. And the conjoint analysis was applied to find out the quantitative values of public preferences for twelve policy alternatives to improve the safety and to support communities surrounding nuclear power plants in Korea. To implement these perception and preference analyses, mail survey was conducted to the Qualified sample who had the experience of visiting nuclear power plant. Diagnosis of their perception pattern for five power production systems was made by the simplified MAU model. Estimation of the quantitative preference values for potential policy alternatives was made by the conjoint measurement technique, which made it possible to forecast the effectiveness of each option. The results from the qualified sample and the methods used in this study would be helpful to set up new policy of nuclear power plant.

• Safety and Health at Work
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• v.7 no.1
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• pp.32-37
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• 2016

Background: Previous research has shown that paramedics are exposed to risks in the form of injuries to the musculoskeletal system. In addition, there are studies showing that they are also at increased risk of cardiovascular disease, cancer, and psychiatric diseases, which can partly be explained by their constant exposure to stress. The aim of this study is to evaluate whether the use of shoulder straps decreases physical effort in the form of decreased heart rate and cortisol concentration. Methods: A stretcher with a dummy was carried by 20 participants for 400 m on two occasions, one with and one without the shoulder straps. Heart rate was monitored continuously and cortisol samples were taken at intervals of 0 minutes, 15 minutes, 30 minutes, 45 minutes, and 60 minutes. Each participant was her or his own control. Results: A significant decrease in heart rate and cortisol concentration was seen when shoulder straps were used. The median values for men (with shoulder straps) at 0 minutes was 78 bpm/21.1 nmol/L (heart rate/cortisol concentration), at 15 minutes was 85 bpm/16.9 nmol/L, and at 60 minutes was 76 bpm/15.7 nmol/L; for men without shoulder straps, these values were 78 bpm/21.9 nmol/L, 93 bpm/21.9 nmol/L, and 73 bpm/20.5 nmol/L. For women, the values were 85 bpm/23.3 nmol/L, 92 bpm/20.8 nmol/L, and 70 bpm/18.4 nmol/L and 84 bpm/32.4 nmol/L, 100 bpm/32.5 nmol/L, and 75 bpm/25.2 nmol/L, respectively. Conclusion: The use of shoulder straps decreases measurable physical stress and should therefore be implemented when heavy equipment or a stretcher needs to be carried. An easy way to ensure that staff use these or similar lifting aids is to provide them with personalized, well-adapted shoulder straps. Another better option would be to routinely sewn these straps into the staff's personal alarm jackets so they are always in place and ready to be used.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.4
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• pp.419-427
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• 2014

Purpose: We propose an effective marketing strategy for eyeglasses stores on the basis of surveys about the relationships between customers' social values, customer satisfaction and selecting glasses store. Methods: All 245 surveys were conducted about customers had visited the eyeglasses store located in Seoul and Northern Gyeonggi-do regions from January 1 to June 30, 2014, and it were analyzed by SPSS v.20.0 statistical package program. Results: The order of customers' social values factors which have an influence on 'Selecting Store' is "Society oriented", "Ability oriented", "Freedom oriented" and "Happiness oriented". Also, the order of customers' social values factors which have an influence on satisfaction is "Society oriented", "Ability oriented". In addition, Customer Satisfaction is affected by Service, one of the factor of 'Selecting Store' factors. Conclusions: Each type of marketing activities should be conducted for customers by their various values. The best plan to elicit good reactions from customers is meeting them through "Society-oriented" factors. Meeting with customers through the "Ability-oriented" factors is second only to the best option. It is shown that the method to increase the satisfaction for customers' return visit is to manage 'Service factors' well.

• Korean Journal of Biological Psychiatry
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• v.22 no.2
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• pp.63-77
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• 2015

Objectives The combination extract of four kinds of herbs, Gastrodia elata, Liriope platyphylla, Dimocarpus longan, and Salvia miltiorrhiza, has shown to have memory improving effects in mice. The aim of this study was to investigate the efficacy and safety of the herbal mixture for improving working memory as well as microstructural changes in white matter integrity in individuals with subjective memory complaints. Methods Seventy-five individuals with subjective memory complaints were assigned to receive either placebo (n = 15) or herbal mixture (low-dose group, n = 30 and high-dose group, n = 30) supplementation in an 8-week, randomized, double-blind, placebo-controlled clinical trial. Changes in working memory performance and fractional anisotropy (FA) values reflecting white matter integrity from baseline to 8-week endpoint were assessed. Results The herbal mixture group showed an increase in working memory performance compared to the placebo group (p for interaction = 0.001). In addition, the herbal mixture group showed an increase in FA values in the temporo-parietal regions (corrected p < 0.05), which are crucially involved in working memory function and are among the most affected regions in patients with cognitive impairments. Conclusions Findings from this study indicate that the herbal mixture may be a promising therapeutic option for individuals with subjective memory complaints.

• Fisheries and Aquatic Sciences
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• v.21 no.7
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• pp.18.1-18.6
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• 2018

Background: Cutaneous bacterial pathogens including Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Propionibacterium acnes are often involved in acne vulgaris. The currently available therapeutic option for these skin pathogens is an antibiotic treatment, resulting in the emergence of antibiotic-resistant bacteria. The objective of this study was to discover an alternative antibacterial agent with lower side effect from marine algae. Results: The ethanolic extract of edible brown algae Ishige okamurae exhibits potent antibacterial activity against cutaneous bacterial pathogens. Among the ethanol soluble fractions, the n-hexane (Hexane)-soluble fraction exhibited the strongest antibacterial activity against the pathogens with MIC values ranging 64 to $512{\mu}g/mL$ and with minimum bactericidal concentration values ranging 256 to $2048{\mu}g/mL$. Furthermore, the combination with Hexane fraction and antibiotics (ceftazidime, ciprofloxacin, and meropenem) exhibited synergistic effect. Conclusion: This study revealed that the I. okamurae extract exhibited a synergistic antibacterial effect against acnerelated cutaneous bacterial pathogens acquired antibiotic resistant. Thus, the results of the present study suggested that the edible seaweed extract will be a promising antibacterial therapeutic agent against antibiotic-human skin pathogens and its infections.

• Development and Reproduction
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• v.17 no.3
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• pp.199-205
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• 2013

Genomic DNAs were extracted from the turtle leg (Pollicipes mitella, 1798) population of Tongyeong, Yeosu and Manjaedo located in the southern sea of Korea. The turtle leg population from Tongyeong (0.929) exhibited higher bandsharing values than did turtle leg from Manjaedo (0.852). The higher fragment sizes (>1,200 bp) are much more observed in the Yeosu population. The number of unique loci to each population and number of shared loci by the three populations, generated by PCR using 7 primers in the turtle leg (P. mitella) population of Tongyeong, Yeosu and Manjaedo. Genetic distances among different individuals of the Tongyeong population of the turtle leg (lane 1-07), Yeosu population of the turtle leg (lane 08-14) and Manjaedo population of the turtle leg (lane 15-21), respectively, were generated using the CLASSIFICATION option in Systat version 10 according to the bandsharing values and similarity matrix. The dendrogram, obtained by the seven decamer primers, indicated three genetic clusters: cluster 1 (TONGYEONG 01 TONGYEONG 07), cluster 2 (YEOSU 08 YEOSU 14), and cluster 3 (MANJEDO 15 MANJEDO 21). Tongyeong population could be evidently discriminated with the other two Yeosu and Manjaedo populations among three populations. The longest genetic distance (0.305) was found to exist between individuals' no. 02 of the Tongyeong population and no. 13 of the Yeosu population. It seems to the authors that this is a result of a high degree of inbreeding in narrow region for a long while.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.3
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• pp.340-344
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• 2005

In high-income Asian countries like Korea and Japan, per capita rice consumption has declined because of the change in consumer' favorite foods from rice to high-cost quality foods. This has forced farmers to reduce rice production. Although fodder rice could be another option to be cultured by farmers, available information concerning rice grain silage has been limited. In the present study, therefore, the difference in the quality of fodder rice silage prepared from either whole crop or grain at different ripening stages was compared. Various supplements were also added into whole crop and grain silages of fodder rice before ensiling, and thereafter, the palatability of prepared silages was determined by beef cattle. At ear emergence stage, the pH values for both grain and whole crop silages were approximately 4.5. In both grain and whole crop silages, the pH values were significantly increased by progressing ripening stages from milk-ripe stage to yellow-ripe stages, and the increase in pH value for grain silage was faster than that for whole crop silage. In the grain silage, the higher lactic acid (LA) content in grain silage seemed to be, the lower pH value was. Both in grain and whole crop silages, pH was significantly decreased by supplementation with LA bacteria. There were no significant differences in feed intake among any treatment groups.

• The Journal of Advanced Prosthodontics
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• v.12 no.2
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• pp.49-54
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• 2020

PURPOSE. The purpose of this study was to compare the performance of Accura to that of the T-scan for indicating occlusal contacts. MATERIALS AND METHODS. Twenty-four subjects were selected. Their maxillary dental casts were scanned with a model scanner. The Stereolithography files of the casts were positioned to align with the occlusal plane. Occlusal surfaces of every tooth were divided into three to six anatomic regions. T-scan and Accura recordings were made during two masticatory cycles. The T-scan and Accura images were captured at the maximum bite force and overlapped to the cast. Photographs of interocclusal records were used as the reference during overlap. The occlusal contacts were counted to compare the T-scan and Accura. McNemar's test was used for statistical significance and the corresponding P-values were calculated from a chi-square distribution with one degree of freedom. The accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of Accura were calculated relative to the T-scan values as a control. RESULTS. No statistical differences (P>.05) were found between the T-scan and Accura methods. The accuracy of Accura was 75.8%, sensitivity was 82.1%, specificity was 60.1%, PPV was 82.9%, and NPV was 60.1%. CONCLUSION. Accura could be another possible option as a computerized occlusal analysis system for indicating occlusal contacts at maximum intercuspation.