• 자연과학논문집
• /
• 제8권2호
• /
• pp.101-109
• /
• 1996

이 논문에서는 기하광학과 회절이론을 통하여 이론적으로 경로손실을 나타내는 식을 유도하였다. 이식을 이용하여 동일 층내에 위치한 안테나간의 전파 특성을 살펴보기 위하여 Bertoni가 사용한 건물과 같은 구조에 대하여 이전의 연구 결과와 비교하였다.

• 대한수학회지
• /
• 제35권3호
• /
• pp.539-557
• /
• 1998

This paper is concerned with the performance evaluation of loss networks. We shall review the Erlang Fixed Point (EFP) method for estimating the blocking probabilities, which is based on an assumption that links are blocked independently. For networks with linear structure, the behaviour of adjacent links can be highly correlated. We shall give particular attention to recently-developed fixed-point methods which specifically account for the dependencies between neighbouring links. For the network considered here, namely a ring network with two types of traffic, these methods produce relative errors typically $10^{-5}$ of that found using the basic EFP approximation.

• Journal of electromagnetic engineering and science
• /
• 제12권1호
• /
• pp.63-69
• /
• 2012

This paper presents the design of a calculable standard dipole antenna with a hybrid balun in the frequency range of 1 GHz to 3 GHz. A new formula of the antenna factor for a dipole antenna with a hybrid balun is derived using the power mismatch-loss concept. The antenna factors derived in this paper are in good agreement with the results calculated from S-parameters. The design results show that the calculable dipole antenna with a hybrid balun can be characterized by power mismatch-loss component factors.

• 한국의류학회지
• /
• 제22권1호
• /
• pp.108-115
• /
• 1998

The objective of this study was to estimate the quantitative loss of the consumer surplus due to the tariffs on clothing imports during the WTO starting periods. For 1984-1996, the import price elasticity of the clothing was estimated from the regression of pet capita clothing imports on Per capita GNP, import price index and domestic producer price index. Then the quantitative losses of the consumer surplus in clothing were obtained from the simplified formula for 1990-1995. In spite of the decrease in textiles St clothing tariff rates, consumer costs were increasing, which was caused by the tremendous increase in clothing imports during the same period. The loss of the consumer surplus was 7131 billion wonts in 1995, which accounted for 6.4% of the total clothing expenditure.

• 대한산업공학회지
• /
• 제25권3호
• /
• pp.351-359
• /
• 1999

We present a new approach to the analysis of mobile cellular communication systems under the environment of mixed platforms adopting a guard channel scheme. We assume general cell residence time distributions according to platform-types. Our system model is based on a heterogeneous M/G/c loss system with customer-dependent guard channels, where heterogeneous customers with different service time distributions have different numbers of their own guard channels. We develop the general formula of steady state probabilities for the heterogeneous M/G/c loss system with customer-dependent guard channels. The mean channel occupancy times of new and handoff calls are rigorously derived under a general setting. Finally, our numerical results show that the blocking probability and the forced termination probability are sensitive to the cell residence time distributions.

• 한국안전학회지
• /
• 제19권4호
• /
• pp.94-100
• /
• 2004

This study delivers the actual condition of investment for industrial accident prevention based on survey of 500 construction sites from 'reports for industry safety and health' published by Korea Occupational Safety & Health Agency (KOSHA). The various research techniques were used such as technical statistic analysis for construction industry, cost comparison of industrial accident prevention and accident loss. A formula was deduced to calculate accident loss and accident frequency by accident prevention cost through regression analysis.

• ETRI Journal
• /
• 제19권1호
• /
• pp.13-25
• /
• 1997

In this paper, we propose a new queuing model, MMDP/MMDP/1/K, for an asynchronous transfer mode(ATM) multiplexer with multiple quality of service(QoS) variable bit rate (VBR) traffic in broadband-integrated services digital network (B-ISDN). We use the Markov Modulated Deterministic Process(MMDP) to approximate the actual arrival process and another MMDP for service process Using queuing analysis, we derive a formula for the cell loss probability of the ATM multiplexer in terms of the limiting probabilities of a Markov chain. The cell loss probability can be used for connection admission control in ATM multiplexer and the calculation of equivalent bandwidth for arrival traffic, The major advantages of this approach are simplicity in analysis, accuracy of analysis by comparison of simulation, and numerical stability.

• ETRI Journal
• /
• 제40권5호
• /
• pp.624-633
• /
• 2018

Fair bandwidth allocation (FBA) has been studied in optical burst switching (OBS) networks, with the main idea being to map the max-min fairness in traditional IP networks to the fair-loss probability in OBS networks. This approach has proven to be fair in terms of the bandwidth allocation for differential connections, but the use of the ErlangB formula to calculate the theoretical loss probability has made this approach applicable only to Poisson flows. Furthermore, it is necessary to have a reasonable fairness measure to evaluate FBA models. This article proposes an approach involving throughput-based-FBA, called TFBA, and recommends a new fairness measure that is based on the ratio of the actual throughput to the allocated bandwidth. An analytical model for the performance of the output link with TFBA is also proposed.

• Korean Journal of Acupuncture
• /
• 제36권4호
• /
• pp.274-280
• /
• 2019

Objectives : This preliminary study investigated the effect of acupuncture treatment on short-term ketogenic diet-induced weight loss and glucose intolerance in mice. Methods : Six-week old male C57BL/6J mice were randomly assigned to 3 groups: normal, KD, and KD+ACU. All the mice except normal group were fed with ketogenic diet formula for 7 weeks and mice in KD+ACU group received acupuncture treatment three times a week. Body weights were measured three times a week, and glucose level was measured on week 1,3,5, and 7. Ketone level was measured on week 3,5, and 7. Results : Ketogenic diet showed short-term weight loss effect, however, acupuncture treatment did not affect on the weight loss. Ketone level was increased in KD fed mice compared to normal diet fed mice and the level was decreased in KD+ACU group on week 3. However, the change was not significantly different compared to KD group on week 7. Glucose intolerance was improved in KD+ACU group compared to KD group. Conclusions : Acupuncture treatment was effective in relieving glucose intolerance, and the results suggest that combining acupuncture treatment with ketogenic diet may complement each therapeutic intervention by improving glucose intolerance but not effecting on weight loss. This study provides meaningful evidence as a preliminary study of acupuncture treatment on ketogenic diet.

• 대한지역사회영양학회지
• /
• 제2권5호
• /
• pp.695-700
• /
• 1997

This study was conducted to investigate the effect of an energy restriction program on the weight loss and changes of the biochemical nutritional status for 35 obese women. The energy restriction program took place over a 3-week period that was devided into two parts. The first part consisted of 750-800kcal diet and the second part of 800-1000kcal. Subjects were provided a low energy formula and a menu for the recommended diet. Anthropometric and biochemical measurement before and after the energy restriction program were estimated. Mean weight loss was 3.0kg, accordingly the obestiy rate was lowered from 40.2 to 34.4, BMI from 29.2 to 28.9 and fat weight from 23.3kg to 21.0kg( <0.01. <0.05). Waist circumference loss was most prominent(4.4%) compared to triceps(21% loss)and hip circumference(2.2%loss). Mean RBC count, hemoglobin and hematocrit were significantly lowered( <0.01) but they were in the normal range. Systolic blood pressure was significantly decreased from 124.1mmHg to 113.1mmHg . Mean SGOT and SGPT were lowered from 29.3u/L to 20.0u/L and from 28.7u/L to 16.6u/L, respectively. It seems that the 3 weeks of energy restriction program used in this study was effective in improving anthropometric measurements without producing deficiency of iron or other susceptible nutrients.(Korean J community Nutrition 2(5) : 695-700,1997)