• Steel and Composite Structures
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• 제27권1호
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• pp.89-94
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• 2018

Uniaxial ratcheting behavior of Z2CND18.12N austenitic stainless steel used nuclear power plant piping material was studied. The results indicated that ratcheting strain increased with increasing of stress amplitude under the same mean stress and different stress amplitude, ratcheting strain increased with increasing of mean stress under the same stress amplitude and different mean stress. Based on least square method, a suitable method to arrest ratcheting by loading the materials was proposed, namely determined method of zero ratcheting strain rate. Zero ratcheting strain rate occur under specified mean stress and stress amplitudes. Moreover, three dimensional ratcheting boundary surface graph was established with stress amplitude, mean stress and ratcheting strain rate. This represents a graphical surface zone to study the ratcheting strain rates for various mean stress and stress amplitude combinations. The graph showed the ratcheting behavior under various combinations of mean and amplitude stresses. The graph was also expressed with the help of experimental results of certain sets of mean and stress amplitude conditions. Further, experimentation cost and time can be saved.

• 대한교통학회지
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• 제25권6호
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• pp.209-230
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• 2007

이 논문은 혼잡현상을 갖는 교통체계의 사회비용함수를 사회비용 최소화문제로부터 도출하여 분석하였다. 이 논문은 이 분야의 기존 연구에서 다루지 않았던 다음의 두 가지를 중점적으로 분석하였다. 하나는 이용자들의 시간가치가 다를 경우에 비용함수의 구조가 어떻게 달라지는지를 검토하는 것이고, 다른 하나는 사회비용함수를 구성하는 공급자 비용함수의 구조를 파악하는 것이었다. 분석의 결과는 다음과 같이 요약될 수 있다. 첫째, 한계사회비용은 특정한 시간가치를 가진 고객이 소비한 시간가치비용과 추가 고객의 처리에 수반되는 시스템 전체의 서비스시간 증가에 따른 한계혼잡비용으로 구성된다. 둘째, 한계혼잡비용은 공급자의 보상한계비용과 같은 바, 후자는 공급자가 추가의 고객을 가장 경제적으로 처리함에 필요한 용량의 변경에 의한 서비스시간의 변화 양에 대한 이용자 전체의 시간가치를 보상해준다는 전제아래서의 공급자 한계비용을 지칭한다. 셋째, 보상한계비용은 서비스시간함수가 산출과 용량에 대해 동차함수일 경우 한계용량비용에 시스템 이용률의 역수를 곱한 값과 같다.

• 한국물환경학회지
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• 제26권4호
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• pp.557-565
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• 2010

Recently, regulations on toxic compounds in aquatic environment have been strengthened in korea due to the increasing public awareness of the water quality. Typically, these regulations include introduction of emerging toxic compounds and stricter effluent limitations for the already regulated compounds. However, too strict regulations may cause excessive burden on the industry. Therefore it is also important to assess the economic impacts when the new effluent limitation guidelines are introduced. The estimation of the additional cost for the wastewater dischargers to meet the new guidelines are based on the selected treatment technology to handle the hazardous substances and the regulatory levels for effluent limitations. To explore the procedures for cost estimation in enforcing new effluent limitations, a case study was performed specially for 1,4-dichlorobenzene. The pollutants of concern are surveyed for different industrial categories and various treatment technologies. For a given pollutant, the general performances of the treatment technologies are surveyed and a representative technology is selected. For a given technology, the capital cost and annual Operation and Maintenance (O&M) cost was calculated. The calculation of baseline costs to operate ordinary treatment technologies is also important. The ratio between the cost for introducing new treatment process and the baseline cost required for conventional technology was used to evaluate the economic impact on the industry. For 1,4-dichlorobenzene, steam stripping and activated carbon processes were selected as the specific treatment technologies. The cost effects to the regulation of the compound were found to be 6.4% and 14.5% increase in capital cost and O&M cost, respectively, at the flow rate over $2,000m^3/d$ for the categories of synthetic resin and other plastics manufacturing industry. For the case of petrochemical basic compounds manufacturing industry, the cost increases were 5.8% and 12.4%, respectively. It was suggested that cost effect analysis to evaluate the economic impacts of new effluent limitations on the industry is crucial to establish more balanced and reasonable effluent limitations to manage the industrial wastewater containing emerging toxic compounds in the wastewater.

• International Journal of Reliability and Applications
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• 제12권2호
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• pp.131-143
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• 2011

In most of literatures of age replacement policy, the authors consider the case that a new item starts operating at time zero and is to be replaced by new one at time T. It is, however, often to purchase used items because of the limited budget. In this paper, we consider age replacement policy of a used item whose age is $t_0$. The mathematical formulas of the expected cost rate per unit time are derived for both infinite-horizon case and finite-horizon case. For each case, we show that the optimal replacement age exists and is finite and investigate the effect of the age of the used item.

• International Journal of Reliability and Applications
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• 제10권1호
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• pp.33-42
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• 2009

In most of literatures of age replacement policy, the authors consider the case that a new item starts operating at time zero and is to be replaced by new one at time T. It is, however, often to purchase used items because of the limited budget. In this paper, we consider age replacement policy of a used item whose age is $t_0$. The mathematical formulas of the expected cost rate per unit time are derived for both infinite-horizon case and finite-horizon case. For each case, we show that the optimal replacement age exists and is finite and investigate the effect of the age of the used item.

• 융합보안논문지
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• 제13권3호
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• pp.9-15
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• 2013

스테레오 매칭 과정에 있어서 매칭 비용을 구하는 것은 매우 중요한 과정이다. 이러한 스테레오 매칭 과정의 성능을 살펴보기 위하여 본 논문에서는 기존에 제안된 매칭 비용 함수들에 대한 기본 개념들을 소개하고 각각의 성능 및 장점을 분석하고자 한다. 가장 간단한 매칭 비용 함수는 매칭 되는 영상의 일관된 밝기를 이용하여 좌, 우 영상 간 서로 대응하는 대응점을 추정하는 과정으로, 본 논문에서 다루는 매칭 비용함수는 화소 기반과 윈도우 기반의 매칭 비용 방법으로 크게 두 가지로 나눌 수 있다. 화소 기반의 방법으로는 절대 밝기차(the absolute intensity differences: AD)와 sampling-intensitive absolute differences of Birchfield and Tomasi (BT) 방법이 있고, 윈도우 기반의 방법으로는 차이 절대 값의 합(sum of the absolute differences: SAD), 차이 제곱 값의 합(sum of squred differences: SSD), 표준화 상호상관성(normalized cross-correlation: NCC), 제로 평균 표준화 상호 상관성(zero-mean normalized cross-correlation: ZNCC), census transform, the absolute differences census transform (AD-Census) 이 있다. 본 논문에서는 앞서 언급한 기존에 제안된 매칭 비용 함수들을 정확도와 시간 복잡도를 측정했다. 정확도 측면에서 AD-Census 방법이 평균적으로 가장 낮은 매칭 율을 보여줬고, 제로 평균 표준화 상호 상관성 방법은 non-occlusion과 all 평가 항목에서 가장 낮은 매칭 오차율을 보여 주지만, discontinuities 평가 항목에서는 블러 효과 때문에 높은 매칭 오차율을 보여 주었다. 시간 복잡도 측면에서는 화소 기반인 절대 밝기차 방법이 낮은 복잡도를 보여 주였다.

• 한국산업융합학회 논문집
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• 제21권3호
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• pp.109-115
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• 2018

This paper proposes the method to develop the fuel of suljigemi pellet using agricultural by-products the occurred during the manufacturing of alcohol. The goal of the development of suljigemi using biomass is to make the pellet fuel of high calorie. The suljigemi pellet is difficult to recycle waste in the manufacture company of alcohol. suljigemi pellet has the effect of zero emission as the soil conditioner using ash after burning. Also suljigemi pellet has the reduction effect of carriage fee, fuel economy and low-cost high-efficiency effects, environmentally clean fuel as CO2 emissions savings. So the technologies of the suljigemi fuel pellet are developing low carbon, green growth renewable energy fuel through futuristic energy system will be. In experiments, suljigemi pellets confirmed the calories by about 10% higher than wood pellets with the same conditions.

• Asian Pacific Journal of Cancer Prevention
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• 제17권9호
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• pp.4421-4426
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• 2016

Background: Smoking is recognized as a main leading preventable cause of mortality and morbidity worldwide. It is responsible for a considerable financial burden both on the health system and in society. This study aimed to examine the effect of smoking on cost of hospitalization and length of stay (LoS) among patients with lung cancer in Iran in 2014. Materials and Methods: A total of 415 patients were included in the study. Data on age, sex, insurance status, type of hospitals, type of insurance, geographic local, length of stay and cost of hospitalization was extracted by medical records and smoking status was obtained from a telephone survey. To compare cost of hospitalization and LoS for different smoking groups, current smokers, former smokers, and never smokers, a gamma regression model and zero-truncated poisson regression were used, respectively. Results: Compared with never smokers, current and former smokers showed a 48% and 35% increase in hospitalization costs, respectively. Also, hospital LoS for current and former smokers was 72% and 31% higher than for never smokers, respectively. Conclusions: Our study indicated that cigarette smoking imposes a significant financial burden on hospitals in Iran. It is, however, recommended that more research should be done to implement and evaluate hospital based smoking cessation interventions to better increase cessation rates in these settings.

• 한국정밀공학회지
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• 제16권7호
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• pp.15-23
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• 1999

With a remarkable expansion of communication industry, a pager or a cellular phone becomes a necessary communication device in modern society. However, a paging signal by a buzzer is often acted as an unpleasant noise in some places, thus necessitating a paging signal by a vibration motor. In this paper, a simpler type of a vibration motor, a coreless permanent magnet(PM) DC motor, is considered to substitute for the conventional vibration motors. Using an analytical method, electromagnetic field and operating torque were calculated for the given inner and outer PM type motors, and the results were confirmed by FEM analysis. As design parameters, number of PM poles, PM radial thickness, coil arc angle and number of winding stacks were chosen for sensitivity analysis. It shows that coil arc angle is the most important design parameter to increase the motor performance, without giving an adverse effect on motor weight, size and manufacturing cost. Based on the analysis of the outer PM type motor, an outer square PM type motor is proposed as the final design. Compared to the outer PM type, outer square type provides more flexibility to attach to the small size cellular phones. With the optimum design of square outer PM DC motor, it can successfully substitute the conventional types with less expensive manufacturing cost. better performance and smaller necessary space.

• 시스템엔지니어링학술지
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• 제12권1호
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• pp.73-87
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• 2016

Combining power generation and water production by desalination is economically advantageous. Most desalination projects use fossil fuels as an energy source, and thus contribute to increased levels of greenhouse gases. Environmental concerns have spurred researchers to find new sources of energy for desalination plants. The coupling of nuclear power production with desalination is one of the best options to achieve growth with lower environmental impact. In this paper, we will per-form a sensitivity study of coupling nuclear power to various combinations of desalination technology: {1} thermal (MSF [Multi-Stage Flashing], MED [Multi-Effect Distillation], and MED-TVC [Multi-Effect Distillation with Thermal Vapour Compression]); {2} membrane RO [Reverse Osmosis]; and {3} hybrid (MSF-RO [Multi-Stage Flashing & Reverse Osmosis] and MED-RO [Multi-Effect Distillation & Reverse Osmosis]). The Korean designed reactor plant, the APR1400 will be modeled as the energy production facility. The economical evaluation will then be executed using the computer program DEEP (Desalination Economic Evaluation Program) as developed by the IAEA. The program has capabilities to model several types of nuclear and fossil power plants, nuclear and fossil heat sources, and thermal distillation and membrane desalination technologies. The output of DEEP includes levelized water and power costs, breakdowns of cost components, energy consumption, and net saleable power for any selected option. In this study, we will examine the APR1400 coupled with a desalination power plant in the Kingdom of Saudi Arabia (KSA) as a prototypical example. The KSA currently has approximately 20% of the installed worldwide capacity for seawater desalination. Utilities such as power and water are constructed and run by the government. Per state practice, economic evaluation for these utilities do not consider or apply interest or carrying cost. Therefore, in this paper the evaluation results will be based on two scenarios. The first one assumes the water utility is under direct government control and in this case the interest and discount rate will be set to zero. The second scenario will assume that the water utility is controlled by a private enterprise and in this case we will consider different values of interest and discount rates (4%, 8%, & 12%).