• 한국보건간호학회지
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• 제16권2호
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• pp.400-411
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• 2002

This study was performed to identify the drug use and reuse relating characteristics and reuse relating factors in illegal drug users. Subjects consisted of 88 illegal drug users. Some of them were confined in a mental hospital or National Forensic Psychiatric Hospital located in Chung-nam province, others on attending a drug abuse prevention program in Seoul Probational Institute. Data were collected during the period from February 1, 2002 to February 25, 2002, and analyzed by SAS program. version 6.12. for Wilcoxon rank sum test, Pearson Correlation, Multiple regression. Results were as follows; 1. Drug use characteristics were as follows. $19.3\%$ was has drug family history and $20.7\%$ was has alcohol family history. Main drug was Phillopon$44.3\%$, inhalants $35.2\%$, LSD et al $22.7\%$. Drug use rate of months was everyday $31.2\%$, every other day $24.4\%$. 2. $100\%$ has experienced abstinence and reuse. Abstinence period was less than 12 months in $49.4\%$ and reuse period was less than 6 months in $58.6\%$. 3. Drug use and reuse characteristics related to general characteristics was identified as below. Abstinence period of male was longer than that of female. Person who have drug family history experienced more drugs and person who have family alcohol history started earlier. 4. Reuse periods was correlated with abstinence periods, age. And abstinence period was correlated with age and outcome that following reuse. 5. The multiple regression was used to identify the relating factors that influence reuse period and abstinence period. At the state of controlling abstinence period. inhalants users have 10.07 days shorter reuse period than others. And abstinence period had lengthened age, bad health status, early initiate age, and long reuse period.

• Industrial Engineering and Management Systems
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• 제12권2호
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• pp.95-102
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• 2013

It is difficult to determine an appropriate discount price for daily perishable products to increase profit from a long-term standpoint. Even if the discount pricing is efficient to increase profit of the day, consumers memorize the sales price and they might hesitate to purchase the product at a regular price the following day. The authors discussed the inventory clearance pricing for a single period in our previous study by constructing a mathematical model to derive an optimal sales price to maximize the expected profit by considering the reference price effect of demand. This paper extends the discussion to handle the discount pricing for multiple periods. A mathematical analysis is first conducted to reveal the properties on an objective function, which is the present value of total expected profits for multiple periods. An algorithm is then proposed to derive an optimal price for asymmetric consumers. Numerical experiments investigate the characteristics of the objective function and optimal pricings.

• 한국건축시공학회지
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• 제18권2호
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• pp.195-202
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• 2018

The defects that are bound to arise in most construction projects cause disputes among the contracting parties regarding the defect warranty liability (DWL)guaranteed by the retention of the contractor's performance security at the end of the performance period of the contract. Most current projects involve a multiple-tier contractual relationship, causing the liability for some defects to overlap. In addition, many construction projects are made up of multiple detailed work types which an expert hired by the owner inspects the part completed by the contractor and pays an interim payment. However, after the completion of work, the contractor will still hold the defect warranty liability. In a scenario in which the work is delayed due to reasons for which the owner is responsible, the defect warranty liability period is also increased, imposing an additional burden on the contractor. In this study, basic research was carried out with the goal of reducing problems related to defect warranty liability Problems related to defect warranty liability cases and the nature of the defect warranty liability period were investigated. Possible solutions to the problems caused by the DWL that were suggested include the separation of the negligence liability period and the strict liability period, as well as the introduction of a retention money system.

• 천문학회보
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• 제39권1호
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• pp.82.1-82.1
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• 2014

The presence of multiple populations is now well-established in most globular clusters (GCs) in the Milky Way. In light of this progress, here we suggest a new model explaining the origin of the Sandage period-shift and the difference in mean period of type ab RR Lyrae variables () between the two Oosterhoff groups. In our models, while matching the observed color-magnitude diagrams, the difference in is naturally reproduced as the instability strip is occupied by different subpopulations with increasing metallicity. The instability strip in the metal-poor group II clusters is populated by second generation stars (G2) with enhanced helium and CNO abundances, while the RR Lyraes in the metal-rich group I clusters are mostly produced by first generation stars (G1) without these enhancements. This population shift within the instability strip can create the observed period-shift between the two groups, since both helium and CNO abundances play a role in increasing the period of RR Lyrae variables. The presence of more metal-rich Oosterhoff group III clusters having RR Lyraes with longest can also be reproduced, if more helium-rich third generation stars (G3) are present in these GCs.

• IEIE Transactions on Smart Processing and Computing
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• 제3권4호
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• pp.173-180
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• 2014

Random access protocols feature inherent sensing functionality and distributed coordination, making them suitable for cognitive radio communication environments, where secondary users must detect the white space of the primary spectrum and utilize the idle primary spectrum efficiently without centralized control. These characteristics have led to the adoption of carrier-sensing-multiple-access/collision-avoidance (CSMA/CA) in cognitive radio. This paper proposes a new analytical framework for evaluating the performance of a CSMA/CA protocol that considers the characteristics of idle periods based on the primary traffic behavior in cognitive radio systems. In particular, the CSMA/CA-based secondary network was analyzed in the terms of idle period utilization, which is the average effective data transmission time portion in an idle period. The use of the idle period was maximized by taking its statistical features into consideration.

• 대한원격탐사학회지
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• 제26권6호
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• pp.721-730
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• 2010

In satellite remote sensing, irregular temporal sampling is a common feature of geophysical and biological process on the earth's surface. Lee (2008) proposed a feed-back system using a harmonic model of single period to adaptively reconstruct observation image series contaminated by noises resulted from mechanical problems or environmental conditions. However, the simple sinusoidal model of single period may not be appropriate for temporal physical processes of land surface. A complex model of multiple periods would be more proper to represent inter-annual and inner-annual variations of surface parameters. This study extended to use a multi-periodic harmonic model, which is expressed as the sum of a series of sine waves, for the adaptive system. For the system assessment, simulation data were generated from a model of negative errors, based on the fact that the observation is mainly suppressed by bad weather. The experimental results of this simulation study show the potentiality of the proposed system for real-time monitoring on the image series observed by imperfect sensing technology from the environment which are frequently influenced by bad weather.

• 한국통신학회논문지
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• 제41권8호
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• pp.924-927
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• 2016

In this paper, we consider a cumulative distribution function (CDF)-based opportunistic scheduling for downlink transmission in a cellular network consisting of a base station and multiple mobile stations. We present a closed-form formula for the average starvation period of each mobile station (i.e., the length of the time interval between two successive scheduling points of a mobile station) over Markov time-varying channels. Based on our formula, we investigate the starvation period of the CDF-based scheduling for various system parameters.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.1005-1006
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• 2008

A mechanical or electrical stimulation to the muscle always produces special phenomena, as silent period. Generally, a mechanical stimulation is followed by a single silent period, and an electrical stimulation is followed by multiple silent periods. In this paper, we propose a new algorithm for determining the duration of the silent period.

• Journal of Acupuncture Research
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• 제32권4호
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• pp.77-89
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• 2015

Objectives : To evaluate the safety of multiple-dose intramuscular Shinbaro Pharmacopuncture in male and female Sprague-Dawley(SD) rats over a period of 4 weeks(12 sessions). Methods : In order to test the safety of multiple-dose intramuscular Shinbaro Pharmacopuncture we used 40 healthy male and female 6-week old SD rats(male weight 171.79~196.37 g, female weight 127.93~146.43 g). Shinbaro Pharmacopuncture was administered intramuscularly to male and female SD rats at doses of 4.6 (low dose group, n=10), 9.2 (moderate dose group, n=10), and 18.5 mg/kg(high dose group, n=10), respectively. General symptoms, body weight changes, blood tests, biochemical testing, necropsy, organ weight and histopathogical findings were examined over a 4-week period. Results : 1. No mortalities or adverse effects were caused by the investigational substance were observed during the study period. 2. There was no significant difference in body weight caused by the the investigational substance across all groups. 3. No significant between-group difference was found to be caused by the investigational substance in blood tests and biochemical testing. 4. No abnormalities were detected by a necropsy examination with the unaided eye at the macro level after treatment with the investigational substance. 5. Difference in organ weight between groups caused by the investigational substance was not found. 6. All groups did not exhibit pathological findings caused by the investigational substance in histopathogical examination. Conclusions : According to these results, Shinbaro Pharmacopuncture has no systemic or organ toxicity with multiple-dose intramuscular administrations in male and female SD rats over a 4-week period (12 sessions). These results imply that no adverse effects are observed at a level (NOAEL) of Shinbaro Pharmacopuncture of 18.5 mg/kg.

• Journal of Power Electronics
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• 제15권3호
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• pp.819-829
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• 2015

This paper presents a shunt active power filter (SAPF) for compensating inter-harmonics and harmonics when inter-harmonics content is evident in the grid. The principle of inter-harmonics generation in the grid was analyzed, and the inter-harmonics effect on repetitive controllers was discussed in terms of control performance. Traditional repetitive controllers are not applicable in inter-harmonic compensation. Moreover, the effect of an ideal controller on harmonics signals was analyzed on the basis of the internal model principle. The repetitive controller was improved in the form of a basis function according to theoretical analysis. The finite-dimensional repetitive controller, which is also called the multiple-period repetitive controller, was designed for the control of multiple periodic signals. A selective harmonic compensation system was developed with SAPF. This system can be used to compensate harmonics and inter-harmonics in the grid. Finally, system control performance was verified by simulation and experimental results.