• 한국국방경영분석학회지
• /
• 제12권1호
• /
• pp.50-70
• /
• 1986

When the ICM is fired in the artillery weapon, it is necessary to determine rounds of munitions for sufficient damage to targets of different sizes and shapes. This paper analyzes all kinds of delivery errors involved in ICM firing, and then develops the target coverage model appropriate for ICM salvos. This model is evaluated through computer simulation. The expected target coverage is measured according to number of salvos, range and probable error, velocity error, battery arrangement, target size, and shell reliability respectively.

• 한국군사과학기술학회지
• /
• 제14권5호
• /
• pp.904-912
• /
• 2011

In this paper, we have proposed a M&S tool for analyzing detection coverage and target localization in bistatic radar system. The detection coverage determined by radar parameters is meaningful when it satisfies the clear line-of-sight condition. We improved the method to find the minimum altitudes of transmitter and receiver for meeting the condition by considering three-dimensional coverage. Its computational burden is not problematic because the calculation is for maximizing the performance of the radar and does not demand a real-time operation. In addition, target localization on three-dimensional earth model based on the information of the height, longitude, and latitude is proposed instead of the previous unpractical calculation on two-dimensional bistatic plane. Its precalculated result can reduce its computation burden and it is suitable for real-time estimation of target location.

• 한국통신학회논문지
• /
• 제35권3B호
• /
• pp.453-461
• /
• 2010

무선 센서 네트워크의 센서 노드들은 한정된 자원을 가지고 있으며 배터리의 교체가 어렵다는 특성을 가지고 있기 때문에 제한된 에너지를 효율적으로 사용하는 기법은 매우 중요하다. 지금까지 이러한 센서 노드의 에너지 소모를 최소화하기 위하여 다양한 스케줄링 문제 및 해결 방안에 관한 연구들이 진행되어 왔다. 특히 CTC(Connected Target Coverage) 문제는 타겟 커버리지와 연결성을 동시에 고려하여 센서 노드들의 효율적인 상태 전이 시점을 결정하는 대표적인 스케줄링 문제로 간주된다. 본 논문에서는 중복되어 센싱되는 타겟을 고려한 보다 올바른 센서 에너지 소비 모델을 제안하고 센서 네트워크의 수명을 더욱 연장 할 수 있는 CMTC(Connected Multiple-Target Coverage) 문제를 제시한다. 또한, 이 문제를 해결하기 위한 SPT(Shortest Path based on Targets) Greedy 알고리즘을 제안하고 시뮬레이션을 통하여 제안기법이 기존기법보다 센서 네트워크의 수명을 더욱 연장하는 기법임을 보인다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제13권11호
• /
• pp.5464-5488
• /
• 2019

The multi-population genetic algorithm in multi-target paths coverage has become a top choice for many test engineers. Also, information sharing strategy can improve the efficiency of multi-population genetic algorithm to generate multi-target test data; however, there is still space for some improvements in several aspects, which will affect the effectiveness of covering the target path set. Therefore, a multi-target paths coverage strategy is proposed by improving multi-population genetic algorithm based on individual information sharing among populations. It primarily contains three aspects. Firstly, the behavior of the sub-population covering corresponding target path is improved, so that it can continue to try to cover other sub-paths after covering the current target path, so as to take full advantage of population resources; Secondly, the populations initialized are prioritized according to the matching process, so that those sub-populations with better path coverage rate are executed firstly. Thirdly, for difficultly-covered paths, the individual chromosome features which can cover the difficultly-covered paths are extracted by utilizing the data generated, so as to screen those individuals who can cover the difficultly-covered paths. In the experiments, several benchmark programs were employed to verify the accuracy of the method from different aspects and also compare with similar methods. The experimental results show that it takes less time to cover target paths by our approach than the similar ones, and achieves more efficient test case generation process. Finally, a plug-in prototype is given to implement the approach proposed.

• 한국의학물리학회지:의학물리
• /
• 제17권1호
• /
• pp.6-16
• /
• 2006

본 연구의 목적은 세기변조 방사선 치료법(IMRT)에 의해 만들어진 DVH를 이용하여 선량의 균등률(homogeneity) 및 덮임률(coverage) 지수를 구하는 간편한 방법을 제시하는 데 있다. 새로 개발된 지수들은 DVH 곡선을 수학적으로 계단 함수에 fitting 함으로써 구해졌다. 새로 제안된 지수 l는 종양에 대한 선량의 덮임률을 잘 나타내고 있으며 이 지수가 작으면 작을수록 더 좋은 덮임률을 보여주고 있다. 또한 종양의 균등률 지수로 제안된 n 지수는 기존에 사용되고 있는 균등률 지수들보다 좀 더 정확하게 선량의 균등성을 나태내고 있음을 확인하였다. 이들 지수를 이용하여 치료계획에 바탕이 되는 토대를 제시하였으며 여기에서 제안된 지수들이 선량의 균등성과 덮임성에 대해 매우 효과적인 방법이 될 수 있음을 보여주고 있다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제12권6호
• /
• pp.2658-2679
• /
• 2018

This paper proposes a novel Random Scheduling Algorithm based on Subregion Coverage (RSASC), to solve the SET K-cover problem (an NP-complete problem). SET K-cover problem distributes the set of sensors into the maximum number of mutually exclusive subsets (MESSs) in such a way that each of them can be scheduled for lifetime extension of WSN. Sensor coverage divides the target region into different subregions. RSASC first sorts the subregions in the ascending order concerning their sensor coverage. Then, it forms the subregion groups according to their similar sensor coverage. Lastly, RSASC ensures the K-coverage of each subregion from every group by randomly scheduling the sensors. We consider the target-coverage and area-coverage applications of WSN to analyze the usefulness of our proposed RSASC algorithm. The distinct quality of RSASC is that it utilizes less number of deployed sensors (33% less) to form the optimum number of MESSs with the higher computational speed (saves more than 93% of the time) as compared to the existing three algorithms.

• Asian Pacific Journal of Cancer Prevention
• /
• 제17권11호
• /
• pp.4935-4937
• /
• 2016

Objective: To compare dosimetric parameters of 3 dimensional conformal radiotherapy (3 DCRT) and intensity modulated radiotherapy (IMRT) in terms of target coverage and doses to organs at risk (OAR) in the management of rectal carcinoma. Methods: In this prospective study, conducted between August 2014 and March 2016, all patients underwent CT simulation along with a bladder protocol and target contouring according to the Radiation Therapy Oncology Group (RTOG) guidelines. Two plans were made for each patient (3 DCRT and IMRT) for comparison of target coverage and OAR. Result: A total of 43 patients were recruited into this study. While there were no significant differences in mean Planning Target Volume (PTV) D95% and mean PTV D98% between 3 DCRT and IMRT, mean PTV D2% and mean PTV D50% were significantly higher in 3 DCRT plans. Compared to IMRT, 3 DCRT resulted in significantly higher volumes of hot spots, lower volumes of cold spots, and higher doses to the entire OAR. Conclusion: This study demonstrated that IMRT achieves superior normal tissue avoidance (bladder and bowel) compared to 3 DCRT, with comparable target dose coverage.

• 대한방사선치료학회지
• /
• 제31권2호
• /
• pp.33-41
• /
• 2019

목 적: 용적변조회전 방사선치료(Volumetric Modulated Arc Therapy, VMAT)시, Planning Target Volume(PTV)을 중복 설정하여 손상위험장기(Organ At Risk, OAR)에 인접한 PTV Coverage 감소를 개선하기 위한 연구이다. 대상 및 방법: 본원에서 전뇌(Whole Brain), 담낭(Gall Bladder), 직장(Rectum) 방사선치료를 받은 환자를 대상으로 하였으며, PTV 내 Coverage가 부족한 부분에 PTV를 중복 적용한 치료계획과 적용하지 않은 치료계획으로 구성하여 Coverage 변화와 최대선량, 선량균질지수(Homogeneity Index, H.I.), 처방선량지수(Conformity Index, C.I.)를 비교하였으며, 손상위험장기(Organ At Risk, OAR)의 최대선량과 평균선량의 변화 또한 비교하였다. 결 과: 중복하여 적용한 PTV의 Coverage는 모든 환자에게서 증가하였고, 이에 따른 영향으로 전체 Coverage 또한 4명의 환자에게서 증가하였다. PTV의 최대선량은 5명의 환자에게서 증가하였으며, 모든 환자의 선량균질지수와 처방선량지수는 큰 차이를 나타내지 않았다. 수정체의 최대선량은 최대 1.12배 증가하였으나, 뇌줄기의 경우 2명의 환자에게서 최대선량이 감소하였다. 안구의 평균선량은 최대 1.15배 증가하였으며, 양측 이하선의 경우 큰 차이를 나타내지 않았다. 담낭암 환자의 경우 간과 결장의 평균선량은 각각 0.95배, 0.94배 감소하였으며, 십이지장의 평균선량은 큰 차이가 없었다. 직장암 환자의 경우 OAR로 설정한 양측 대퇴골두와 방광 모두 평균선량은 감소하였으며, 전체 MU는 1명을 제외한 4명의 환자에게서 비슷한 수준으로 나타났다. 결 론: OAR의 선량제한을 고려해가면서 적절하게 사용한다면, PTV의 Coverage 개선에 유용한 방법이라 생각한다.

• Asian Pacific Journal of Cancer Prevention
• /
• 제14권4호
• /
• pp.2243-2248
• /
• 2013

Background: To compare the dosimetric coverage of target volumes and organs at risk in the radical treatment of nasopharyngeal carcinoma (NPC) between intensity-modulated radiotherapy (IMRT) and three-dimensional conformal radiotherapy (3DCRT). Materials and Methods: Data from 10 consecutive patients treated with IMRT from June-October 2011 in Penang General Hospital were collected retrospectively for analysis. For each patient, dose volume histograms were generated for both the IMRT and 3DCRT plans using a total dose of 70Gy. Comparison of the plans was accomplished by comparing the target volume coverage (5 measures) and sparing of organs at risk (17 organs) for each patient using both IMRT and 3DCRT. The means of each comparison target volume coverage measures and organs at risk measures were obtained and tested for statistical significance using the paired Student t-test. Results: All 5 measures for target volume coverage showed marked dosimetric superiority of IMRT over 3DCRT. V70 and V66.5 for PTV70 showed an absolute improvement of 39.3% and 24.1% respectively. V59.4 and V56.4 for PTV59.4 showed advantages of 18.4% and 16.4%. Moreover, the mean PTV70 dose revealed a 5.1 Gy higher dose with IMRT. Only 4 out of 17 organs at risk showed statistically significant difference in their means which were clinically meaningful between the IMRT and 3DCRT techniques. IMRT was superior in sparing the spinal cord (less 5.8Gy), V30 of right parotid (less 14.3%) and V30 of the left parotid (less 13.1%). The V55 of the left cochlea was lower with 3DCRT (less 44.3%). Conclusions: IMRT is superior to 3DCRT due to its dosimetric advantage in target volume coverage while delivering acceptable doses to organs at risk. A total dose of 70Gy with IMRT should be considered as a standard of care for radical treatment of NPC.

• 한국국방경영분석학회지
• /
• 제3권1호
• /
• pp.97-107
• /
• 1977

This report examines several models, such as random or area bombardment, salvo fire and pattern fire, for the computation of target coverage when multiple rounds are fired at a target. Fractional kill of a fragment sensitive target by a fragmenting projectile as a function of the number of rounds fired is compared for two salvo fire models. The first is a standard salvo fire model in which N rounds are fired at the same aim point, in the second model single kill probability is computed for a fragment sensitive target and then fractional kill from the firing of N rounds is computed according to the assumption that the effects of each round are independent. Because the method of solution becomes very laborious for large patterns, this report gives a method only for the case of evaluating the effectiveness of stick and trianglar pattern fire. The need for the sophisticated and complicated target coverage models is demonstrated by the results of computations performed in this report.