• 한국국방경영분석학회지
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• 제28권2호
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• pp.56-69
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• 2002

A technique of finding both probability density and distribution function for interkilling times is considered and demonstrated. An important result is that any arbitrary interfiring time random variables fit to this study, The interfiring renewal density function given a certain interfiring probability density function can be applied to obtain the corresponding interkilling renewal density function which helps us to estimate the expected number of killing events in a time period. The numerical inversion of Laplace transformation makes these possible and the results appear to be excellent. In case of ammunition supply is limited, an alternative way of getting the probability density function of time to the killing is investigated. The convolution technique may give us a means of settling for this new problem.

• 한국수학사학회지
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• 제30권2호
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• pp.71-86
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• 2017

When looking for solutions of Jisuguimundo with magic number 88~92 and 94~98, alternating method is applied to each possible partitions of each magic number. But this method does not apply in case of finding solutions of Jisuguimundo with magic number 87, 93, and 99. In this study, it is shown that solutions of Jisuguimundo with magic number 87, 93, and 99 can be found by applying alternating method to two partitions. These two partitions are derived partitions obtained by each partitions of magic number 87, 93, and 99. If every number from 1 to 30 which satisfy every unit path of Jisuguimundo can be found in all components of these two derived partitions, that arrangement is just a solution of Jisuguimundo. The method suggested in this study is more developed one than the method which is applied to just one partition.

• Anatomy and Cell Biology
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• 제56권4호
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• pp.566-569
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• 2023

Knowledge of anatomical variations is important so as to avoid potential iatrogenic injury or misdiagnosis on imaging. Here we report an unusual finding and relationship between the tibial nerve and popliteal vein. During the routine dissection of an adult cadaver, it was noted that a branch of the tibial nerve in the popliteal fossa pierced the most distal part of the popliteal vein. This unusual finding is described and relevant reports in the literature discussed. Our hopes are that such a report might help surgeons avoid injury to such a fenestrated popliteal vein and the tibial nerve branch traveling through it therefore decreasing patient morbidity.

• 한국전자파학회논문지
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• 제21권4호
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• pp.433-442
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• 2010

본 논문에서는 멀티베이스라인 인터페로미터 방향 탐지 시스템에서 진폭 및 위상 부정합 오차를 보정할 수 있는 공분산행렬 기반 자체 교정 알고리즘을 제안한다. 제안된 기법은 비용함수를 정의한 후 제한 조건을 갖는 비선형 최소화 방법으로서, 공간 섹터를 이용하여 부정합 오차를 획기적으로 교정하는 알고리즘이다. 다만 공간 섹터를 선정하기 위하여 초기 추정각을 요구하는 단점이 있으나, 이는 일반적인 비선형 최소화 문제의 공통적인 단점이다. 적절한 공간 섹터 간격을 선정하여 시뮬레이션한 결과, 제안된 방법이 기존 인터페로미터 방식보다 표본바이어스, 표본표준편차, 평균제곱오차면에서 획기적으로 우수한 통계적 성능을 보여주었다. 더구나 섹터 간격이 도래각과 $5^{\circ}$ 이내일 경우에, 30 dB의 진폭 부정합 및 $50^{\circ}$ 이상 큰 값의 위상 부정합이 발생하는 경우에도 획기적인 보정 능력을 보여주었으며, 신호대 잡음비에도 덜 민감한 특징을 나타내었다.

• 한국수학교육학회지시리즈C:초등수학교육
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• 제19권1호
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• pp.31-45
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• 2016

본 연구는 초등수학의 여러 영역 중 도형 학습에서 오류 찾기 활동을 통하여 학생들이 범하는 오류 유형이 어떤 것이 있는지를 알아보고 이러한 활동이 학생들의 수학 학업 성취도와 추론 능력에 미치는 영향을 알아 보는데 있다. 연구 결과 학생들이 가장 많이 보이는 오류는 부정확한 개념과 정의에 의한 오류(55.8%)이며, 문제해결을 기피하는 오류(14.8%)를 제외하면, 시각적 자료를 부적절하게 사용하는 오류(11.4%), 문제 자료를 곡해하는 오류(9.2%), 기술적인 오류(6.2%), 논리적으로 부적절한 추론으로 인한 오류(1.6%), 문제 자료를 불충분하다고 여기는 오류(1.0%) 순으로 나타났다. 오류 찾기 활동을 수업에 적용한 결과, 사전 및 사후 학업 성취도 검사와 추론 능력 검사에서 유의수준 5% 이내의 유의미한 차를 보였다. 이는 오류 찾기 활동이 수학 학업 성취도와 수학적 추론 능력 향상에 도움을 주는 교수 방법 중 한 가지가 될 수 있음을 알 수 있었다.

• 지역사회간호학회지
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• 제25권3호
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• pp.159-169
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• 2014

Purpose: The purpose of this study was to evaluate the effectiveness of case management for patients with hypertension on their health status and medical service utilization. Methods: This study was a secondary analysis of data collected for a larger study of chronic disease management in 2008 using the National Health Insurance Corporation database. A total of 12,944 patients who received case management for hypertension were included in this analysis. The subjects of case management were classified into subgroups, namely, over-use, under-use, and non-use groups according to the amount of medical service utilization. To compare the medical service utilization, a control group was selected randomly. The data were analyzed through descriptive statistics, McNemar test, and ANOVA. Results: All the subgroups displayed significant differences in blood pressure, self-management, social support, and their characteristics of medical service utilization. The total medical expense of the under-use and non-use groups increased after case management. However, there was no decrease in the medical expense of the over-use group. Conclusion: This finding suggests that there is a need to re-examine why patients overuse medical services and to supplement specific strategies for encouraging appropriate medical service utilization, and enhancing case management efforts for the over-use group.

• Tuberculosis and Respiratory Diseases
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• 제41권5호
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• pp.574-578
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• 1994

저자들은 폐쇄성 흉부외상 1년 후, 경미한 호흡 곤란으로 내원한 환자에서 단순 흉부X-선상 폐실질에는 이상이 없고 기관지 내시경 검사상 기관지 web형태로 발현한 외상성 기관지 파열을 경험하였기에 문헌 고찰과 함께 보고하는 바이다.

• Kyungpook Mathematical Journal
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• 제28권2호
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• pp.185-196
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• 1988

We study existence of polynomial integrating factors and solutions F(x, y)=c of first order nonlinear differential equations. We characterize the homogeneous case, and give algorithms for finding existence of and a basis for polynomial solutions of linear difference and differential equations and rational solutions or linear differential equations with polynomial coefficients. We relate singularities to nature of the solution. Solution of differential equations in closed form to some degree might be called more an art than a science: The investigator can try a number of methods and for a number of classes of equations these methods always work. In particular integrating factors are tricky to find. An analogous but simpler situation exists for integrating inclosed form, where for instance there exists a criterion for when an exponential integral can be found in closed form. In this paper we make a beginning in several directions on these problems, for 2 variable ordinary differential equations. The case of exact differentials reduces immediately to quadrature. The next step is perhaps that of a polynomial integrating factor, our main study. Here we are able to provide necessary conditions based on related homogeneous equations which probably suffice to decide existence in most cases. As part of our investigations we provide complete algorithms for existence of and finding a basis for polynomial solutions of linear differential and difference equations with polynomial coefficients, also rational solutions for such differential equations. Our goal would be a method for decidability of whether any differential equation Mdx+Mdy=0 with polynomial M, N has algebraic solutions(or an undecidability proof). We reduce the question of all solutions algebraic to singularities but have not yet found a definite procedure to find their type. We begin with general results on the set of all polynomial solutions and integrating factors. Consider a differential equation Mdx+Ndy where M, N are nonreal polynomials in x, y with no common factor. When does there exist an integrating factor u which is (i) polynomial (ii) rational? In case (i) the solution F(x, y)=c will be a polynomial. We assume all functions here are complex analytic polynomial in some open set.

• 품질경영학회지
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• 제50권2호
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• pp.265-286
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• 2022

Purpose: The time and cost of a project activity exists in a selected mode and there is a quality level for the selected mode, and the time and cost of the current activity is determined by the quality level of the preceding activity. When an activity is a predecessor activity of an activity, it is characterized as a trade-off problem in which the time and cost of the activity are determined according to the quality level of the activity. Methods: A neighbor search heuristic algorithm obtains a solution by (1) randomly determining the mode, quality level, and assignment order for each activity. (2) get a solution by improving the solution by changing the possible modes and quality levels; (3) to find a solution by improving the solution from the point where it is feasible to advance the start time. Here, Case[1] is a method to find the optimal solution value after repeating (1). Case [2] is a method for finding a solution including (1) and (2). Case [3] refers to a method for finding solutions including (1), (2), and (3). Results: It can be seen that the value of the objective function presented by the algorithm changes depending on how the model of the heuristic algorithm is designed and applied. In other words, it suggests the importance of algorithm design and proves the importance of the quality problem of activities in the project schedule. Conclusion: A study significance of the optimization algorithm and the heuristic algorithm was applied to the effect of the quality of the preceding activity on the duration and cost of itself and the succeeding activity, which was not addressed in the project schedule problem.

• Journal of Yeungnam Medical Science
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• 제27권2호
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• pp.146-149
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• 2010

Pelioid hepatocellular carcinoma(HCC), a type of atypical HCC, is a rare histologic type of HCC. The radiologic findings of the pelioid HCC is differ from the typical type of HCC. To our knowledge, this case report is the second literature to show the enhancing features of a pelioid HCC on dynamic computed tomography (CT).Here we describe the dynamic CT findings in a case of surgically confirmed pelioid HCC.