• Journal of the Korea Society for Simulation
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• v.8 no.3
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• pp.77-89
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• 1999

Simulating rare events, such as probability of cell loss in ATM networks, machine failure in highly reliable systems, requires huge simulation efforts due to the low chance of occurrence. Importance Sampling (IS) has been applied to accelerate the occurrence of rare events. However, it has a drawback of effective biasing scheme to make the estimator of IS unbiased. Adaptive Importance Sampling (AIS) employs an estimated sampling distribution of IS to the system of interest during the course of simulation. We propose Nonparametric Adaptive Importance Sampling (NAIS) technique which is nonparametrical version of AIS. We test NAIS to estimate a probability of rare event in M/M/1 queueing model. Comparing with classical Monte Carlo simulation, the computational efficiency and variance reductions gained via NAIS are substantial. A possible extension of NAIS regarding with random number generation is also discussed.

• Management Science and Financial Engineering
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• v.20 no.2
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• pp.33-37
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• 2014

A flow shop scheduling problem involves scheduling jobs on multiple machines in series in order to optimize a given criterion. The flow time of a job is the amount of time the job spent before its completion and the stretch of the job is the ratio of its flow time to its processing time. In this paper, a hybrid genetic algorithm (HGA) approach is proposed for minimizing the total stretch in flow shop scheduling. HGA adopts the idea of seed selection and development in order to reduce the chance of premature convergence that may cause the loss of search power. The performance of HGA is compared with that of genetic algorithms (GAs).

• Journal of the Korea Society for Simulation
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• v.8 no.1
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• pp.51-61
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• 1999

A cell scheduling method of Queue for the ATM switch is proposed and simulated. In this paper, we present the cell scheduling method proper to the proposed queue and the improved queue with Queue Sharing(QS) structure for CBR, VBR, ABR traffic. The proposed QS structure minimizes the CLS(Cell Loss Ratio) of ABR traffic and decreases the CLR of bursty VBR traffic. Also we propose a cell scheduling method using VRR(Variable Round Robin) scheme proper to the high-speed(ATM) switch. The VRR scheme provides a fairness in terms of service chance for the queues in the ATM switch as well as QOS of their cell delay characteristic of CBR and VBR traffic, QOS of ABR CLR. The simulation results show the proposed method achieves excellent CLR and average cell delay performance for the various ATM traffic services in the Queue Sharing structure.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.6
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• pp.29-35
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• 2013

The heterogeneous emergency communication radios is used at disaster management agencies of Korea to response activity in the event of disaster. The compensation method by communication connection time difference is necessary to seamless voice communication because radios have different communication method and delay. In this paper, we suggested solution for voice transmission chance and data loss problem.

• 대한예방의학회:학술대회논문집
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• 1994.02b
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• pp.261-264
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• 1994

This paper proposes a new method for planning randomized clinical trials. This method is especially suited to comparison of a best standard or control treatment with an experimental treatment. Patients are allocated into two groups by a random or chance mechanism. Patients In the first group receive standard treatment; those in the second group are asked if they will accept the experimental therapy; if they decline. they receive the best standard treatment. In the analyses of results. all those in the second group. regardless of treatment. are compared with those in the first group. Any loss of statistical efficiency can be overcome by Increased numbers. This experimental plan is indeed a randomized clinical trial and has the advantage' that, before providing consent, a patient will know whether an experimental treatment is to be used.

• Proceedings of the Korea Information Processing Society Conference
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• 2019.10a
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• pp.678-679
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• 2019

In this paper, we developed a medical computer application for both disable children and adults in order to provide the chance to communicate easily with others. Although there are many mobile healthcare apps available nowadays, we believe that users should also have many options for choosing different types of healthcare programs developed for computers. That's why we have developed ConWis. This application helps a person with hearing loss, voice, speech, or language disorder to communicate easily with others. Through this software, hearing and understanding what is being said more clearly or to express thoughts become easier. To use this software, patient should input a sentence and it will be converted to audio speech using built-in voices for man or woman. In addition to that, it can convert voice that is received by microphone into text and display it on the screen.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.13 no.2
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• pp.63-71
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• 2005

There is a concern in the aviation community that pilot schedules can lead to fatigue and increased chance of an aviation accident. Yet despite this concern, there is little empirical studies showing the relationship between pilot fatigue and commercial aviation accidents. At this point of view, countering fatigue is a challenging proposition in complex aviation operations. However, with appropriate planning, many strategies can contribute to pilot alertness and flight safety. With proper education program, sustaining a physiological fit, a right knowledge about pilot fatigue can design a safety operations. On this study, I inquire into the ways of enhancing pilot's efficiency from fatigue.

• International Journal of Computer Science & Network Security
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• v.24 no.4
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• pp.60-66
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• 2024

Host's data during transmission. Data tempering results in loss of host's sensitive information, which includes number of VM, storage availability, and other information. In the distributed cloud environment, each server (computing server (CS)) configured with Local Resource Monitors (LRMs) which runs independently and performs Virtual Machine (VM) migrations to nearby servers. Approaches like predictive VM migration [21] [22] by each server considering nearby server's CPU usage, roatative decision making capacity [21] among the servers in distributed cloud environment has been proposed. This approaches usage underlying server's computing power for predicting own server's future resource utilization and nearby server's resource usage computation. It results in running VM and its running application to remain in waiting state for computing power. In order to reduce this, a decentralized decision making hybrid model for VM migration need to be proposed where servers in decentralized cloud receives, future resource usage by analytical computing system and takes decision for migrating VM to its neighbor servers. Host's in the decentralized cloud shares, their detail with peer servers after fixed interval, this results in chance to tempering messages that would be exchanged in between HC and CH. At the same time, it reduces chance of over utilization of peer servers, caused due to compromised host. This paper discusses, an roatative decisive (RD) approach for VM migration among peer computing servers (CS) in decentralized cloud environment, preserving confidentiality and integrity of the host's data. Experimental result shows that, the proposed predictive VM migration approach reduces extra VM migration caused due over utilization of identified servers and reduces number of active servers in greater extent, and ensures confidentiality and integrity of peer host's data.

• Journal of Korean Medical classics
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• v.35 no.2
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• pp.99-120
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• 2022

Objectives : To analyze symptoms of olfactory dysfunction caused by COVID-19 from a Korean Medical Perspective. Methods : Previous studies dealing with olfactory dysfunction accompanying COVID-19 were studied and analyzed for general characterization. Physiology and pathology of olfactory functions within the classical texts of Korean Medicine were collected and analyzed, through which symptoms of olfactory dysfunction in COVID-19 were examined. Results : Olfactory dysfunction manifested in high ratios in the early stages of confirmed COVID-19 cases, at times independent of other nasal symptoms such as blockage or discharge. There was a high chance of loss of taste being accompanied, while mental problems such as a tendency to have difficulty concentrating were present as well. In most cases, recovery took one to two weeks. From a Korean Medical perspective, physiology of olfactory function is closely linked to the Lungs, Ancetral Qi[宗氣], and the Heart, while its dysfunction could be explained by pathological factors such as Wind-Cold, Fire stagnation, Qi deficiency, Wind stroke, etc. Conclusions : In the context of external contraction disease[外感病], olfactory dysfunction could be caused by problems in the Lungs and Stomach that are responsible for breathing, or the Heart which is involved in recognizing and differentiating scent. General characteristics of COVID-19 imply it to be closely related to the Heart. In clinical application, overall symptoms need to be considered in diagnosis and treatment planning, after which further approaches could made to determine the problem to be of the Lung and Stomach, or of the Heart.

• Women's Health Nursing
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• v.3 no.2
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• pp.208-223
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• 1997

This study was made to suggest the nursing strategies for promoting the behaviors about bone mass health behaviors in order to prevent middle aged women's osteoporosis. This study was a descriptive-correlational design that also concerned to the types which improve bone mass promoting behaviors by inspecting patterns of health locus of control method out of recognizable variables of health improving models influencing on these bone mass promoting behaviors. For these purpose, data were collected by self reported questionnaire in middle school, from 158 women living in Seoul. The measuring tools used in this study about bone mass promoting behaviors and multidimensional health locus of control, were developed by author on the basis of literature review and analyzed by SPSS-PC window, into pearson's correlation, ANOVA, multiple regression, cluster analysis. Data was analyzed as follows. 1. 6 Multidimensional health locus of control scale clusters were existed. : a)cluster I (pure internal), b)cluster II(pure chance), c) cluster III(Believer in control), d), cluster IV(Type VI), e)cluster V(yea sayer), f) cluster VI(nay sayer). There were no findings of the powerful others external cluster and double external cluster. 2. The higher the value of internal health locus of control was, the better the bone mass promoting behaviors were(r=.2891, $p=.00^{**}$). The higher the value of chance external health locus of control was, the worse the bone mass promoting behaviors were(r=-.1367, $p=.00^{**}$). 3. On the basis of these relationships, 6 clusters were significantly different in the bone mass promoting behaviors(F=2.27, $p=.05^*$). The value of bone mass promoting behaviors was ranked the order of type VI>believer in control>pure internal>yea sayer>nay sayer>pure chance external highly. 4. Bone mass promoting behaviors were not significantly different as to age. Suggestion. Based on the results from the study, I would like to make some suggestions as follows. 1) To delay the loss of bone mass in middle aged women, the study on the cluster of the multidimensional health locus of control should be conducted repeatedly. 2) The tool of multidimensional health locus of control should be developed through a qualitative method adjusted on Korean' health culture.