• Journal of the Korea Society of Computer and Information
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• v.11 no.6 s.44
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• pp.279-287
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• 2006

This paper proposes a method to detect fall action by using stereo images to recognize emergency situation. It uses 3D information to extract the visual information for learning and testing. It uses HMM(Hidden Markov Model) as a recognition algorithm. The proposed system extracts background images from two camera images. It extracts a moving object from input video sequence by using the difference between input image and background image. After that, it finds the bounding rectangle of the moving object and extracts 3D information by using calibration data of the two cameras. We experimented to the recognition rate of fall action with the variation of rectangle width and height and that of 3D location of the rectangle center point. Experimental results show that the variation of 3D location of the center point achieves the higher recognition rate than the variation of width and height.

• Korean Journal of Clinical Pharmacy
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• v.19 no.2
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• pp.96-104
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• 2009

배경: 당뇨병 환자에게 관상동맥심질환은 생존률, 건강 상태 유지 및 삶의 질에 주요한 영향을 미치는 합병증이며 적극적인 당뇨병 치료는 이러한 심혈관 합병증을 예방할 수 있으나 당뇨병의 적극적 치료와 관리에는 많은 비용이 소요된다. 목적: 제2형 당뇨병 환자를 대상으로 메트포르민과 글리메피리드 병합요법과 메트포르민과 피오글리타존 병합요법의 비용-효과성을 비교하고자 하였다. 연구방법: 마르코프 코호트 프로세스(Markov Cohort Process Model) 모형을 이용하여 비용-효과분석을 실시하였다. 연장된 수명 (life years gained, LYG)과 삶의 질(quality)을 보정하여 증가된 QALYs를 주요 효과 지표로 측정하였고, 총비용으로는 직접의료비용과, 환자와 가족의 교통비를 직접비의료비용으로 고려하였고 환자와 가족의 시간비용을 간접비용으로 포함하였다. 연구결과: 비용-효과분석 결과, 메트포르민과 글리메피리드 병합요법의 경우 총 비용은 5,962,288원, 효과는 7.94LYG, 6.43QALY이었다. 반면 메트포르민과 피오글리타존 병합요법은 총 비용 10,982,243원, 효과 8.62LYG, 6.99QALY으로, 점증적 비용-효과비(ICER)는 7,402,663원/LYG과 8,934,546원/QALY 이었다. 결론: 우리 사회의 연장된 수명(LYG)에 따른 지불의사가 700만원 이하인 경우는 메트포르민과 글리메피리드 병합요법이 비용-효과적인 대안이며 700만원 이상인 경우에는 메트포르민과 피오글리타존 병합요법이 비용-효과적인 대안이 될 수 있다.

• Journal of Gastric Cancer
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• v.14 no.4
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• pp.259-265
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• 2014

Purpose: Survival analysis of gastric cancer patients requires knowledge about factors that affect survival time. This paper attempted to analyze the survival of patients with incomplete registered data by using imputation methods. Materials and Methods: Three missing data imputation methods, including regression, expectation maximization algorithm, and multiple imputation (MI) using Monte Carlo Markov Chain methods, were applied to the data of cancer patients referred to the cancer institute at Imam Khomeini Hospital in Tehran in 2003 to 2008. The data included demographic variables, survival times, and censored variable of 471 patients with gastric cancer. After using imputation methods to account for missing covariate data, the data were analyzed using a Cox regression model and the results were compared. Results: The mean patient survival time after diagnosis was $49.1{\pm}4.4$ months. In the complete case analysis, which used information from 100 of the 471 patients, very wide and uninformative confidence intervals were obtained for the chemotherapy and surgery hazard ratios (HRs). However, after imputation, the maximum confidence interval widths for the chemotherapy and surgery HRs were 8.470 and 0.806, respectively. The minimum width corresponded with MI. Furthermore, the minimum Bayesian and Akaike information criteria values correlated with MI (-821.236 and -827.866, respectively). Conclusions: Missing value imputation increased the estimate precision and accuracy. In addition, MI yielded better results when compared with the expectation maximization algorithm and regression simple imputation methods.

• Journal of the Korean Data and Information Science Society
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• v.26 no.1
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• pp.101-109
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• 2015

SMRs (standardized mortality rates) for major diseases, accidents, cancer are considered in small areas of administrative units such as Eup/Myeon/Dong from years 2005 to 2008. Due to small sample issue in small areas, the precision of directly estimated crude SMR for each area can be low. In this study, we consider the HGLM (hierarchical generalized linear model) with MRF (Markov random field) to account for the spatial correlations among the small areas. The effects of covariates for cause of mortality by Dongs in Seoul and disease maps based on the estimated SMR are presented. The results suggest how we analyze and interpret the difference in mortalities by small areas such as Dongs by revealing the spatial patterns.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.6
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• pp.155-164
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• 2004

Recently, we have remarkable developments in intelligent robot systems. The remarkable features of intelligent robot are that it can track user and is able to doface recognition, which is vital for many surveillance-based systems. The advantage of face recognition compared with other biometrics recognition is that coerciveness and contact that usually exist when we acquire characteristics do not exist in face recognition. However, the accuracy of face recognition is lower than other biometric recognition due to the decreasing in dimension from image acquisition step and various changes associated with face pose and background. There are many factors that deteriorate performance of face recognition such as thedistance from camera to the face, changes in lighting, pose change, and change of facial expression. In this paper, we implement a new sliding active camera system to prevent various pose variation that influence face recognition performance andacquired frontal face images using PCA and HMM method to improve the face recognition. This proposed face recognition algorithm can be used for intelligent surveillance system and mobile robot system.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.12
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• pp.59-70
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• 2003

Proposed CCRSVP (Candidate Casting RSVP) algorithm is a new fast handoff method which uses advanced multicasting method and RSVP for IEEE 802.11 Wireless LAN (WLAN) environments. The proposed algorithm shows good performance in the handoff latency and the B/W efficiency aspect and guarantees QoS because it uses L2 information (BSSID) of WLAN and starts to reserve resources and multicast packets before L2 handoff completes. We also propose a Markov chain performance analysis model in which we can analyze the handoff performance of various handoff algorithms. Using the model, we compare bandwidth efficiency of the proposed algorithm with existing handoff algorithms which use RSVP by analyzing blocking probability of session, resource usage, and the average number of ongoing session in a cell. The results show that the proposed algorithm shows better performance than the existing algorithms in the above three performance aspects.

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.1
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• pp.12-17
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• 2005

The segment matching method shows better performance than the global and points-based methods to compare reference signature with an input signature. However, the segment-to-segment matching method has the problem of decreasing recognition rate according to the variation of partitioning points. This paper proposes a fusion model based on the segment matching and HMM to construct a more reliable authentic system. First, a segment matching classifier is designed by conventional technique to calculate matching values lot dynamic information of signatures. And also, a novel HMM classifier is constructed by using the principal component analysis to calculate matching values for static information of signatures. Finally, SVM classifier is adopted to effectively combine two independent classifiers. From the various experiments, we find that the proposed method shows better performance than the conventional segment matching method.

• Journal of the Korean Institute of Intelligent Systems
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• v.26 no.3
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• pp.202-207
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• 2016

Checkpoint placement is an effective fault tolerance technique against transient faults in which the task is re-executed from the latest checkpoint when a fault is detected. In this paper, we propose a new checkpoint placement strategy separating data saving and fault detection processes that are performed together in conventional checkpoints. Several fault detection processes are performed in one checkpoint interval in order to decrease the latency between the occurrence and detection of faults. We address the placement method of fault detection processes to maximize the probability of successful execution of a task within the given deadline. We develop the Markov chain model for a real-time task having the proposed checkpoints, and derive the optimal fault detection and checkpoint interval.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.5
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• pp.147-154
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• 2015

Satellite broadcasting networks, like if you have if you have just received information that everyone must bring the required security attributes this earth should be done as encryption. In this paper, a satellite communication network AH additional security header in transport mode IPsec VPN by applying the SHA-256 and MD-5 authentication algorithm to authenticate the data portion Error rate and analyze the BER and Throughput. First, to generate a normal IP packet added to IPsec transport mode security header AH were constructed internal authentication data by applying the SHA-256 and MD-5 algorithm. Channel coder was applied to the Rate Compatible Punctured Turbo Codes, packet retransmission scheme Hybrid-ARQ Type-II and Type-III were used. Modulation method was applied to the BPSK, the wireless channel Markov channel (Rician 80%, Rayleigh 20% and Rician 90%, Rayleigh 10%) as an authentication algorithm according to the satellite channel state analyzed how they affect the error rate and Throughput.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.12B
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• pp.2109-2119
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• 2000

In this paper, the Packet CDMA Reservation ALOHA protocol is proposed to support the multi-traffic services such as voice and videophone services with handoff calls, high-rate data and low-rate data services efficiently on the multi-rate transmission in uplink cellular systems. The frame structure, composed of the access slot and the transmission slot, and the proposed access permission probability based on the estimated number of contending users for each service are presented to reduce MAI. The assured priority to the voice and the videophone handoff calls is given through higher access permission probability. And through the proposed code assignment scheme, the voice service can be provided without the voice packet dropping probability in the CDMA/PRMA protocols. The code reservation is allowed to the voice and the videophone services. The low-rate data service uses the available codes during the silent periods of voice calls and the remaining codes in the codes assigned to the voice service to utilize codes efficiently. The high-rate data service uses the assigned codes to the high-rate data service and the remaining codes in the codes assigned to the videophone service. Using the Markov-chain subsystem model for each service including the handoff calls in uplink cellular systems, the steady-state performances are simulated and analyzed. After a round of tests for the examples, through the proposed code assignment scheme and the access permission probability, the Packet CDMA Reservation ALOHA protocol can guarantee the priority and the constant QoS for the handoff calls even at large number of contending users. Also, the data services are integrated efficiently on the multi-rate transmission.