• 시스템엔지니어링학술지
• /
• 제16권1호
• /
• pp.1-8
• /
• 2020

In this paper we proposed to develop the reliability growth planning for the One-shot system using the PM2-Discrete model. The PM2-Discrete is the methodology specifically developed for discrete systems and is the first quantitative method available for formulating detailed plans in the discrete usage domain. First, the parameters RG, RI, T, MS and d of the PM2-Discrete model are set. Second, the case analysis was performed on One-shot system A. Third, the input parameter values were applied to drive the R(t) equation. Finally, using RGA 11 Software, the reliability Growth Planning Curve of One-shot system A was constructed. Also, the sensitivity analyses are performed for the changes of model parameters. The results of this study can be usefully used in establishing the reliability growth planning curve of the One-shot system.

• Annals of Clinical Neurophysiology
• /
• 제2권2호
• /
• pp.119-124
• /
• 2000

Background : We studied EEG changes during pilocarpine-induced status epilepticus(SE), a widely used model whose EEG characteristics have not been fully described previously. Methods : Male Sprague-Dawley rats weighing 250-350 grams were used as subjects. SE was induced 5-7 days after placement of chronic epidural electrodes, using 360-380 mg/Kg pilocarpine IP. Rats were observed with continuous EEG recording following pilocarpine injection until end of the SE episode. Results : SE occurred in 10/12 rats studied. SE began with a series of discrete seizures $11.1{\pm}3.93$ minutes after pilocarpine injection. $5.2{\pm}2.71$ seizures occurred over $10.9{\pm}4.62$ minutes, until the EEG converted to a waxing and waning pattern, during which the amplitude and frequency of epileptiform activity increased. After $1.4{\pm}1.82$ minutes, a pattern of continuous high amplitude rapid spiking was established. Continuous spiking continued for $3.4{\pm}0.48$ hours with a very gradual decline in amplitude and frequency, until periodic epileptiform discharges(PEDs) began to occur. The EEG consisted primarily of PEDs for another $7.4{\pm}3.09$ hours, until electrographic generalized seizures began to occur. These continued for $5.8{\pm}4.82$ hours until death. Duration of SE was $17.0{\pm}5.88$ hours. Flat periods were a prominent feature during all EEG patterns in this model. Conclusion : EEG features distinctive in pilocarpine SE(but not unique to it) include flat periods during all patterns and resumption of continuous spiking episodes after the onset of PEDs. The sequence of discrete seizures to waxing and waning to continuous spiking to PEDs was identical to that which has been described in humans and other animal models.

• 대한기계학회논문집B
• /
• 제35권5호
• /
• pp.491-501
• /
• 2011

국내에서 널리 사용되는 500 MW급 미분탄 화력발전에서 2개의 PM (pollution minimum) 버너의 최적 운전 범위를 확인하기 위하여 DPM (discrete phase model)을 활용하여 수치계산을 수행하였다. 본 연구는 저가의 아역청탄의 활용 증진을 위하여 다양한 조건에서 탄 종별로 연구를 수행하는데 그 목적이 있다. 탄 종별로 미분탄의 질량 유량, 1차 공기의 질량 유량, 그리고 미분탄의 입자 크기 분포를 달리하여 공기/석탄의 분배비의 영향을 조사하였다. 이러한 매개변수에 관하여 PM 버너에서의 공기/석탄의 분배비의 최적운전조건을 도출하고 이에 대해 논의하고자 한다.

• Ocean and Polar Research
• /
• 제30권2호
• /
• pp.141-148
• /
• 2008

This paper aims at estimating consumer surplus for recreational sea fishing in Tongyeong coastal area using individual travel cost method. A Poisson model (PM), a negative binomial model (NBM), a truncated Poisson model (TPM), and a truncated negative binomial model (TNBM) are applied for individual travel cost method in order to account characteristics of count data (non-negative discrete data.) The survey was conducted for 462 inshore anglers using personal interview method in Tongyeong during July and October 2007. Respondents were asked about how often they do fishing, travel costs, catch, income, and so on. Because of over-dispersion problem in PM and TPM, NBM and TNBM were considered to be more appropriate statistically. All parameters estimated are statistically significant and theoretically valid. As the results based on TNBM, consumer surplus per trip was estimated to be 183,486 won, total consumer surplus per person and per year 3,399,658 won, and the marginal effect of consumer surplus on % changes in catch rate is 185,372 won.

• Korean Chemical Engineering Research
• /
• 제57권1호
• /
• pp.90-104
• /
• 2019

본 연구에서는 시간별 실제 기상데이터를 토대로 한 CALPUFF 모델링 수행을 통하여 민원지역에 대한 신뢰성이 있는 모델링 결과를 도출하였다. 무창형 계사 P1 및 P2의 방진망 구조물(chamber) 및 개방형 계사 P3로부터의 오염원 배출 및 확산거동을, 부피오염원으로서의 CALPUFF 모델링 또는 각 방향의 배출면적을 가중치로 한 수직 배기의 평균 선속도인 모델 배출 선속도($u^M_y$)를 적용한 점오염원으로서의 최종 CALPUFF 모델링으로 구현하였다. 또한 계사 P1, P2 및 P3에서의 배출되는 악취 및 분진오염원 배출량에 대한 각각의 제거효율(0, 20, 50 및 80%) 또는 각각 대응되는 emission rate (100, 80, 50 및 20%)에 따른 시나리오를 기본으로, CALPUFF 모델링을 수행하여 각각에 대한 민원지역의 농도예측을 수행하였다. 이러한 민원지역에 대한 암모니아, 황화수소, $PM_{2.5}$ 및 $PM_{10}$에 대한 농도예측과 악취방지법 및 대기환경법에서 요구되는 오염물질 농도와 비교하여, 계사 P1, P2 및 P3에 요구되는 암모니아, 황화수소, $PM_{2.5}$ 및 $PM_{10}$에 대한 제거율을 산정하였다. 그 결과로서, "P1, P2 및 P3에서 각각의 배출농도를 줄인 비율만큼 각각의 discrete receptor에서의 농도가 같은 비율로 감소한다"는 가정(a priori assumption)이 본 CALPUFF 모델링 범위 내에서 적용 가능함이 입증되었다. 한편 부피오염원을 적용한 CALPUFF 모델링을 수행한 경우에서 방지시설의 요구되는 제거효율은, 점오염원을 적용한 CALPUFF 모델링을 수행한 경우와 비교하였을 때에 P1의 경우에는 상호간에 유사하였으나, P2와 P3에서 암모니아와 $PM_{10}$의 경우에 더 높게 나타났다. 그럼에도 불구하고 민원해결을 위한 안전한 접근방법으로서 부피오염원으로서 CALPUFF 모델링을 선정하였다. 이에 따라서 본 연구에서는 암모니아, 황화수소, $PM_{2.5}$ 및 $PM_{10}$와 같은 오염원배출에 대하여 무창형 계사 P1 및 P2에 요구되는 정량적 방지수준을 타당하게 도출하였다.

• Ocean and Polar Research
• /
• 제36권3호
• /
• pp.289-302
• /
• 2014

This paper aims to evaluate the indirect economic damages to anglers of the marine recreational charter caused by marine pollution associated with the Herbei Spirit vessel, which spilled 12,547 kl of crude oil in Taean coastal areas in December 2007. In order to evaluate the indirect cost to anglers of the charter fishing, consumer surplus for charter fishing is estimated using a Poisson model (PM), a negative binomial model (NBM), a truncated Poisson model (TPM), and a truncated negative binomial model (TNBM), which account for the characteristics of count data (non-negative discrete data), for individual travel cost method (ITCM). Because of over-dispersion problem in PM and TPM, NBM and TNBM are considered to be more appropriate statistically. All parameters such as income, fishing careers, travel cost and catch that are estimated are statistically significant and theoretically valid. Based on TNBM results, consumer surplus per trip and per person was estimated to be 277 thousand won, total consumer surplus per person and per year about 2.3 million won, and the marginal effect of consumer surplus on % changes in catch rate is about 33 thousand won. The consumer surplus was converted into total indirect economic damages for aggregation which are evaluated to be 125 billion won, reflecting the number of anglers and damage rate.

• Journal of Biosystems Engineering
• /
• 제21권3호
• /
• pp.283-292
• /
• 1996

Automatic guidance of farm tractors would improve productivity by reducing operator fatigue and increasing machine performance. To control tractors within $\pm$5cm of the desired path, fuzzy and adaptive steering controllers were developed to evaluate their characteristics and performance. Two input variables were position and yaw errors, and a steering command was fed to tractor model as controller output. Trapezoidal membership functions were used in the fuzzy controller, and a minimum-variance adaptive controller was implemented into the 2-DOF discrete-time input-output model. For unit-step and composite paths, a dynamic tractor simulator was used to test the controllers developed. The results showed that both controllers could control the tractor within $\pm$5cm error from the defined path and the position error of tractor by fuzzy controller was the bigger of the two. Through simulations, the output of self-tuning adaptive controller was relatively smooth, but the fuzzy controller was very sensitive by the change of gain and the shape of membership functions. Contrarily, modeling procedure of the fuzzy controller was simple, but the adaptive controller had very complex procedure of design and showed that control performance was affected greatly by the order of its model.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1999년도 제14차 학술회의논문집
• /
• pp.278-280
• /
• 1999

This paper proposes controlling of temperature in an oven by using 4 bits Integral - Cycle Binary Rate Modulation (IBRM) method and ac line with frequency 50 Hz. Microcontroller MCS-51 controls IBRM according to Proportional Integral controller (PI) function. Discrete signals are used in the system modeled by using Ziegler Nichols principle for analyzing the stability before designing the system. This procedure makes it easy to investigate system response. The system is implemented by 4 bits digital circuit which gives 320 patterns of ac signal fur controlling the generation of energy for 3,000 watts thermal coil every 20 ms of each cycle. We divide scan time (Ts$\sub$n/) in to 20 intervals, 1 ms interval is selected to generate 16 patterns IBRM. Because of this method gives the ripple lower than 2% it generates less noise fur system. Moreover, we can consider whole system from the time model of control procedure and IBRM algorithm at 40-200$^{\circ}C$ with ${\pm}$ 1$^{\circ}C$ error in the 1 cubic meter oven.

• 한국지능시스템학회논문지
• /
• 제16권2호
• /
• pp.179-184
• /
• 2006

신경회로망을 동적 정보처리에 응용하기 위해서는 비대칭 결합 신경회로망에서 생성하는 동적 상태천이에 관한 직관적 이해가 필요하다. 자기결합을 갖고 결합하중치가 비대칭인 순환결합형 신경회로망은 복수 개의 리미트사이클을 기억할 수 있다는 것이 알려져 있다. 현재까지 이산시간 모델의 네트워크에 대한 상태천이 해석은 상세하게 이루어져 왔다. 그러나 연속시간모델에 대한 해석은 네트워크 규모의 증가에 따른 급격한 계산량의 증가 때문에 그다지 활발하게 연구가 이루어지지 않고 있다. 본 논문에서는 각 뉴런이 최근접 뉴런에만 이진화된 결합하중 +1 및 -1로 연결된 연속시간모델 순환결합형 신경회로망의 동적인 상태천이 특성을 해석하여 이산시간 모델에서 기억 가능한 리미트사이클과의 차이점을 분석하였다. 또한 뉴런의 활성화 함수가 완전선형인 경우와 구분선형 근사인 네트워크에 대한 리미트사이클의 안정성을 해석하였다.