• Journal of the Korean Statistical Society
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• v.7 no.1
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• pp.61-80
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• 1978

This paper presents general solutions for stochastic square duels with continuous interfiring times and various firing strategies such as standby (S), concentrated (C), seperated (I) and random (R) firings. Analysis of these square duels with negative exponential interfiring times and equivalent values of rates of fire and single shot kill probabilities reveal three important facts: i) Strategy (C) is advantageous against the opponent's strategy (S) and the advantage becomes more pronounced for lower values of single shot kill probabilities. ii) Strategy (I) is always better than strategy (C) no matter which of (C) and (I) the opponent uses and its relative advantege increases to a quarter as single shot kill probabilities increase to one but decreases to zero as they go to zero. iii) However, strategy (I) has no advantage over strategy (C) for small values of single shot kill probabilities. In this paper, square duels with strategies (C) and (I) are based on the assumptions that duelists are homogeneous and both duelists of one side fire simultaneously. The problem of relaxing these assumptions and extension of square ($2 \times 2$) duels to more general ($m \times n) duels are now being investigated.

• Research in Mathematical Education
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• v.15 no.1
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• pp.59-68
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• 2011

This paper proposes a modified category framework derived from VAMP and VIMT projects for describing teachers' mathematical and pedagogical values, and examines the dialectical relations between values awareness/willingness and teaching, based on case studies of student teachers of secondary mathematics from a follow-up project of VIMT. The preliminary results show that student teachers would teach certain values depending on the awareness of values priority, willingness to teach, their teaching capabilities and classroom conditions. So, mathematics teacher educators should provide relevant courses to facilitate student teachers to be aware of their implicit values and be willing to enact these values, and to empower student teachers with the knowledge and experiences to teach the values.

• Journal of Korean Neurosurgical Society
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• v.64 no.3
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• pp.418-426
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• 2021

Objective : A role of diffusion-weighted imaging (DWI) in the diagnosis of cerebral venous thrombosis (CVT) is not well-understood. This study evaluates the effectiveness of DWI in the diagnosis of CVT. Methods : Literature search was conducted in electronic databases for the identification of studies which reported the outcomes of patients subjected to DWI for CVT diagnosis. Random-effects meta-analyses were performed to achieve overall estimates of important diagnostic efficiency indices including hyperintense signal rate, the sensitivity and specificity of DWI in diagnosing CVT, and the apparent diffusion coefficient (ADC) of DWI signal areas and surrounding tissue. Results : Nineteen studies (443 patients with 856 CVTs; age 40 years [95% confidence interval (CI), 33 to 43]; 28% males [95% CI, 18 to 38]; symptom onset to DWI time 4.6 days [95% CI, 2.3 to 6.9]) were included. Hyperintense signals on DWI were detected in 40% (95% CI, 26 to 55) of the cases. The sensitivity of DWI for detecting CVT was 22% (95% CI, 11 to 34) but specificity was 98% (95% CI, 95 to 100). ADC values were quite heterogenous in DWI signal areas. However, generally the ADC values were lower in DWI signal areas than in surrounding normal areas (mean difference-0.33×10-3 ㎟/s [95% CI, -0.44 to -0.23]; p<0.00001). Conclusion : DWI has a low sensitivity in detecting CVT and thus has a high risk of missing many CVT cases. However, because of its high specificity, it may have supporting and exploratory roles in CVT diagnosis.

• Geomechanics and Engineering
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• v.24 no.2
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• pp.115-127
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• 2021

This paper investigates the effects of soaking on a lime stabilized high plasticity clay and evaluates the implications for pavement design. In this context, the soil was stabilized by 4%, 6% and 9% hydrated lime. The soil was pulverized in two different gradations so that representative field gradations could be simulated. Both soil pulverization levels passed the relevant field gradation criteria. Curing durations were chosen as 7 days, 28 days and 56 days. Two groups of samples were prepared and were tested in unconfined compression test apparatus to measure the strength and secant modulus at failure values. One of the groups was tested immediately after curing. The other group of samples were first cured and then subjected to soaking for ten days before testing. Visual observations were made on the samples during the soaking period. The results showed the superiority of fine soil pulverization over coarse soil pulverization for unsoaked conditions in terms of strength and modulus values. Soaking of the samples affected the unconfined compressive strength and modulus values based on lime content, curing duration and soil pulverization level. In soaked samples, fine soil pulverization resulted in higher strength and modulus values compared to coarse soil pulverization. However, even with fine soil pulverization, effects of soaking on modulus values were more significant. A new term named as "Soaking Influence Factor (SIF)" was defined to compare the reduction in strength and modulus due to soaking. The data was compared with the relevant design guidelines and an attempt was made to include Soaking Influence Factors for strength and modulus (SIFS and SIFM) into pavement design processes. Two equations which correlated secant modulus at failure to unconfined compressive strength were proposed based on the samples subjected to soaking. The results of this study showed that in order to decrease the diverse effects of soaking for lime stabilized soils, soil pulverization level should be kept as fine as possible in the field. Importance of proper drainage precautions in the pavements is highlighted for better performance of the pavements.

• Journal of Korean Academy of Nursing
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• v.25 no.2
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• pp.279-294
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• 1995

The purpose of this study was to determine values and value changes in clinical nurses in clinical situations. A survey was conducted of 200 nurses of one of university hospital in Seoul Korea. This study was conducted between July 1 and July 5, 1994, using the Survey of Interpersonal Values (SIV) developed by L. V. Gordon, and standardized for Korea by Kyung Hye Lee & Eung Yun Hwang. The results of the study were as follows, 1. The clinical nurses surveyed showed Independence(18.32 : 63rd percentile) as their highest value, with Support(14.8 : 62nd percentile) next and then Benevolence(16.28 53rd percentile), Leadership(9.06 : 46th percentile), Conformity(18.15 : 42nd percentile) and Recognition(18.32 : 41s1 percentile) in that order in the area of general values. Using a standardised women's value Indicator, the clinical nurses value orientation was within the 32nd∼69th percentile indicating means found among Korean women in general. 2. Looking at how the values were related to demographics, Leadership was most highly valued among the 30∼34 year olds and least valued among the 25∼29 year olds. Unmarried nurses valued Independence more than married nurses did, and junior college graduate nurses valued Conformity more than baccalaureate graduate nurses did. 3. The study showed that the values of with less than one year (16.00) clinical experience were higher than those who had over 10 years (13.60) clinical experience (p<.05). Therefore clinical experience did not positively influence value orientation for clinical nurses. 4. There was no significant differences in the value of nurses in relation to their workplace, their level of motivation, or their aptitude. The study shows that clinical nurses have similar values compared with ordinary Korean women. This means that professional nurses may not be able to satisfy client needs and also that they do not have satisfaction and a positive attitude regarding the nursing profession. Therefore it is suggested that new strategies and continuing education programs be established to help clinical nurses fomulate higher values.

• Journal of the Korean Society of Food Culture
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• v.24 no.6
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• pp.702-710
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• 2009

The purpose of this study was to identify the competing values leadership of restaurant general managers and to investigate the impact of their competing values leadership on employee job satisfaction and turnover intention. A sample of full-time restaurant employees (n=360, 36% response) completed an e-mail survey. The results showed that among the eight sub-dimensions of competing values leadership roles, the monitor (4.04), producer (4.01), and director (3.99) roles were perceived as the most frequently used leadership styles of managers compared to broker (3.78), innovator (3.83), and mentor (3.91) roles (p <0.001). Additional T-test results suggested that an employees' gender had an influence on how he/she perceived the leadership style of their manager. Male employees were more likely to perceive that the director and mentor roles (4.19) were performed very well by their managers, while female employees perceived that their managers concentrated more on monitor (3.98) and producer (3.96) roles rather than on broker (3.73) and innovator (3.79) roles (p<0.05). It was found that manager competing values leadership had a significant correlation with employee job satisfaction, and the mentor, coordinator, and innovator manager roles explained the relationship with 42.1% based on multiple regression analysis (p<0.001). In further findings, the manager competing values leadership roles had an effect on employee turnover intention. The results of the data were as follows: mentor and facilitator roles promoted a decrease in employee turnover intention and the director role caused employee turnover intention to increase. Ultimately, this study will be useful for restaurant managers to guide the application of appropriate competing values leadership roles in order to strengthen employee job satisfaction and to reduce turnover intention.

• Journal of the Korean Statistical Society
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• v.10
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• pp.91-96
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• 1981

The development of Minimum Norm Quadratic Unbiased Estimation (MINQUE) has introduced a unified approach for the estimation of variance components in general linear models. The computational problem has been studied by Liu and Senturia (1977) and Goodnight (1978, setting a-priori values to 0). This paper further simplifies the computation and gives efficient and compact computational algorithm for the MINQUE and dispersion matrix in general linear random model.

• The Korean Journal of Financial Studies
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• v.3 no.2
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• pp.235-256
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• 1996

This paper studies evaluation of illiquid assets by using a consumption and investment model. In particular, the paper defines the marginal values of illiquid assets and shows how optimal consumption and investment policies are related to the marginal values. The general results are illustrated by two concrete examples.

• Archives of Plastic Surgery
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• v.35 no.5
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• pp.527-532
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• 2008

Purpose: Transverse type or volar oblique type of defect of thumb tip can be covered by Moberg flap or second toe pulp free flap. We compared these two methods in functional result, patients' satisfaction, and sensation, etc. to find a better way to cover the defect of the thumb tip. Methods: From 2003 to 2006, we chose the patients randomly with preoperative pictures. The patients had the defect of the thumb tip which is either transverse or volar oblique type. The 6 patients were treated with Moberg flap and other 6 patients were treated with second toe pulp free flap. We have analyzed the results by 2 point discrimination, side pinching power test, pulp to pulp pinching power test, pain scales (visual analogue scale), satisfaction scales of the patients (functional and aesthetic), the degree of the range of motion, etc. Results: All flaps survived without any complications. In the cases of Moberg flaps, the value of static 2 point discrimination test was 5.6 mm, and the value of moving 2 point discrimination test was 4.8 mm. In the cases of second toe pulp free flaps, the values were 9.6 mm and 9.3 mm. In the cases of Moberg flaps, the value of the Side pinch power test was 6.6 kg, 4.4 kg. In the case of second toe pulp free flaps, the values were 4.8 kg and 2.5 kg. The value of aesthetic satisfaction scale of the patients in Moberg flaps was 5.6, the value of functional satisfaction scale of the patients was 3.6. In cases of second toe pulp free flaps, the values were 5.6 and 3.6. The active range of motion of Interphalangeal joint in the cases of Moberg flaps was 46.6 degree, and the active range of motion of metacarpophalangeal joint was 55 degree, in the cases of second toe pulp free flaps, the values were 36.6 degree and 59 degree. Conclusion: As a result, when the defect of the thumb tip is transverse or volar oblique type, we suggest that the operators choose Moberg flap to cover the defect of the thumb tip.

• BMB Reports
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• v.28 no.3
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• pp.204-209
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• 1995

The pH dependence of kinetic parameters in the amination direction of the aspartase from Hafnia alvei has been determined. The V/K for fumarate is bell shaped with pK values of 6.4 and 8.7. The maximum velocity for fumarate is also bell shaped with pK values of 7.2 and 9.1. The pH dependence of 1/K, for potassium (competitive inhibitor of ammonia) decreases at low pH with pK 7.6. Together with data [Yoon and Cook (1994) Korean J. Biochem. 27, 1-5] on the deamination direction of the aspartase, these results are consistent with two enzyme groups which are necessary for catalysis. An enzymatic group that must be deprotonated has been identified. Another enzyme group must be protonated for substrate binding. Both the general base and general acid group are in a protonation state opposite that in which they started when aspartate was bound. A proton is abstracted from C-3 of the monoanionic form of L-aspartate by an enzyme general base with, a pK of 6.3~6.6 in the absence and presence of $Mg^{2+}$ Ammonia is then expelled with the assistance of a general acid group giving $NH_{4+}$ as the product.