This paper deals with the problem of determining the retailer's optimal price and order size under the condition of order-size-dependent delay in payments. It is assumed that the length of delay is a function of the retailer's total amount of purchase. The constant price elasticity demand function is adopted which is a decreasing function of retail price. Investigation of the properties of an optimal solution allows us to develop an algorithm whose validity is illustrated through an example problem.
판 논문은 구조뭄의 동역학 및 열단성 연성문제 해석을 위 한 통합된 유한요소법을 개 발하논데 초접을 누고
있다. 첫 째로. 열전도 방정식이l 열변위라는 묵리량을 도엽하여 풍역학의 운동 빙정식파 유사하도록 유도한 후.
변분법과 일반좌표계를 이용하여 시간영역에서 정식화하였다 둘째포, 두 뱅정식어] 라블라스 변 판을 동시에 도
입하고 - 공간변수안을 갖는 형성함수짜 가증잔여번을 적용하여 유한요소식을 변환영역에서 표 헌 하였다. 연성된
빙정 식 을 운지l 의 특성에 따라서 분류하였고 정식화 파정을 검숭하였다 또한 수치해석 알고리 늠 이 갖는 수치 역
변환의 정성적인 경향에 대하여 검토하였다-
역삼투 및 투과 증발막 분리공정이 nylon 4 blended 막을 사용하여 물-에탄올 계에 대하여 실험적으로 비교되어졌다. 위 두 공저의 이론적 비교를 다루었던 전 논문과 마찬가지로 투과 증발 공정의 분리 효율이 역삼투 공저의 경우 보다 더 좋음을 알 수 있었다. 그러나 투과도 데이타는 막의 결함들로 인하여 엉뚱한 결과를 보였다.
본 논문에서는 역삼투막 공정과 투과 증발막 공정이 Paul과 Ebra-Lima 모델을 사용하여 이론적으로 서로 비교되어졌다. 이 모델로부터 막내에 있는 액의 농도를 역삼투 공정의 경우 압력이 막의 윗쪽에 가하여졌을 때 (반면에 투과 증발 공정의 경우는 가하여진 압력이 무한대일 때) 막 -n-hexane 그리고 rubber 막-benzene 계들에 대하여 계산되어졌다. 또한 polyethylene-n-hexane 그리고 polyethlene-benzene 계들에 대하여 역삼투 및 투과 증발 공정의 투과도가 계산되어졌고 비교되어졌다. 이론적으로는, 투과 증발 공저으이 투과도가 역삼투 공저의 투과도 보다 더 컸음을 알 수 있었다.
한국산 Longidoridae 과 선충을 채집하여 분류동정한 결과 경상북도에서 Xiphinema속의 X. zulu, X. setariae 그리고 Longidorus속의 L. sylphus등 3종이 우리나라 미기록종으로 밝혀졌으며 이들의 형태적 특징, 채집지, 기주식물 등을 보고한다.
우리나라에서 참깨나 목화에 기생하여 위조병을 일으키는데 Fusarium oxsporum f. vasinfectum의 생육에 미치는 질소원의 종류 및 농도의 영향을 구명하고자 본연구에 착수하였다. 본연구의 결과로부터 질소원의 종류 및 농도의 차이가 Fusarium oxysporum f. vasinfectum의 생육에 큰 영향을 미친다는 것을 알았다. 공시한 4종의 질소원 중에서 Nitrate N나 Urea N가 Ammonia N 또는 Ammonium and Nitrate N 보다 공시균의 생육에 대하여 더욱 알맞는 질소원이었다. 그 중에서도 Nirtrate N는 타른 N원보다 훨씬 넓은 농도범위에서 본균에 의하여 이용되므로 가장 알맞는 질소원이라고 할 수 있다. 한편 Ammonia N는 공시균의 균계생장이나 포자형성의 현저한 감소와 더불어 기형적인 파형균총 또는 염주상균계세포를 농도에 관계없이 형성하므로 질소원으로서의 이용가치가 거의 없다. Ammonia N가 공시균의 생육에 미치는 영향은 파형균총 또는 염주상균계형성으로 보아 Phenoxy 화합물이 타른 진균의 생육에 미치는 영향과 흡사하다. Ammonium and Nitrate N도 50meg. 이상의 농도에서 공시균의 균계생장 또는 포자형성을 감소시키는 한편 파형균총과 같은 이상생육이 다소간음폐되기는 하나 적제 Ammonia N에서 유래하는 파형균총을 유기하므로 알맞는 질소원이라고 생각할 수 없다. 따라서 Ammonia N 단독 또는 타질소원과 Ammonia N의 결합태는 Fusarium oxysporum f. vasifectum의 생육을 위한 질소원으로서는 부적당하다.
The demand for transportation is increasing due to the continuous generation of radioactive wastes. Especially, considering the geographical characteristics of Korea and the location characteristics of nuclear facilities, the demand for maritime transportation is expected to increase. If a sinking accident happens during maritime transportation, radioactive materials can be released into the ocean from radioactive waste transportation containers. Radioactive materials can spread through the ocean currents and have radiological effects on humans. The effect on humans is proportional to the concentration of radioactive materials in the ocean compartment. In order to calculate the concentration of radioactive materials that constantly flow along the ocean current, it is necessary to divide the wide ocean into appropriate compartments and express the transfer processes of radioactive materials between the compartments. Accordingly, this study analyzed various ocean transfer evaluation methodologies of overseas maritime transportation risk codes. MARINRAD, POSEIDON, and LAMER codes were selected to analyze the maritime transfer evaluation methodology. MARINRAD divided the ocean into two types of compartments that water and sediment compartments. And it was assumed that radionuclides are transfered from water to water or from water to sediment. Advection, diffusion, and sedimentation were established as transfer process for radionuclides between compartments. MARINRAD use transfer parameters to evaluate transer processes by advection, diffusion, and sedimentation. Transfer parameters were affected by flow rate, sedimentation rate, sediment porosity, and etc. POSEIDON also divided the ocean into two types that water and sediment compartment, each compartments was detaily divided into three vertical sub-compartment. Advection, diffusion, resuspension, sedimentation, and bioturbation were established as transport processes for radionuclides between compartments. POSEIDON also used transfer parameters for evaluating advection, diffusion, resuspension, sedimentation, and bioturbation. Transfer parameters were affected by suspended sediment rates, sedimentation rates, vertical diffusion coefficients, bioturbation factors, porosity, and etc. LAMER only considered the water compartment. It divided the water compartment into vertical detailed compartments. Diffusion, advection and sedimentation were established as the nuclide transfer processes between the compartments. To evaluated the transfer processes of nuclides for diffusion and advection, LAMER calculated the probability with generating random position vectors for radionuclides’ locations rather than deterministic methods such as MARINRAD’s transfer parameters or POSEIDON’s transfer rates to evaluate transfer processes. The results of this study can be used as a basis for developing radioactive materials’ ocean transfer evaluation model.
Heavy water primary system decontamination technology is essential to reduce worker exposure and improve safety during maintenance and decommissioning of nuclear facilities. Advanced decontamination technology development aims to secure controlled decontamination technologies that can reduce the cost of radiation exposure and dramatically reduce the amount of secondary waste generated when decontaminating large equipment and large-area facilities. We conducted a study to identify candidate corrosion inhibitors through the literature and analyze the degree of corrosion of carbon steel samples. Countries with advanced nuclear technology have developed chemical decontamination technology for the entire nuclear power generation system and applied it to the dismantling and maintenance of nuclear power plants. In the decontamination process, the corrosion oxide film must be removed. If the base metal is corroded by the decontaminant in this process, additional secondary waste is generated and treatment costs increase. Therefore, it is necessary to develop a corrosion inhibitor that inhibits the corrosion of the carbon steel base metal in the decontamination process to generate a secondary waste liquid that is favorable for waste reduction and treatment. In this presentation, a study was conducted to analyze the extent of corrosion on a carbon steel base material and identify candidate materials for corrosion inhibition testing. Samples were analyzed using optical microscopy and EPMA analysis to determine the thickness of the corroded oxide film. EPMA analysis also allowed us to map the elemental distribution of the carbon steel corrosion layer, which we plan to quantify in the future. The candidate materials for organic-based corrosion inhibitor were also selected based on their inhibition mechanism; having high electronegative elements for coordinate covalent bonding at metal surface and hydrophobic nonpolar group for preventing access of corrosive substances.The selection of candidate materials for corrosion inhibition testing was based on the mechanism of the corrosion inhibitor. Organic-based corrosion inhibitors are adsorbed by donor-acceptor interactions between metal surfaces and highly electronegative elements. Corrosion can also be inhibited by arranging hydrophobic nonpolar groups on metal surfaces in the solution direction to prevent access of corrosive substances.
Despite its advantages such as safety, unnecessary pretreatment, and decontamination of waste with complex geometry, conventional ultrasonic decontamination technology has been only used to remove loose contaminants, oil and grease, not fixed contaminants due to the limitations in increasing the intensity in the high frequency range. Thus, ultrasound has been used as an auxiliary method to accelerate chemical decontamination of radioactive wastes or chemicals were added to the solution to increase the decontamination efficiency. The recently developed high-intensity focused ultrasound (HIFU) decontamination technology overcomes these limitations by combining multiple frequencies of ultrasonic waves in a specific arrangement, making it possible to remove most fixed contaminants, including radioactive micro particles less than 1 micrometer within half an hour. KEPCO NF and EnesG developed mobile HIFU decontamination equipment and successfully demonstrated the decontamination effect on various radionuclides found in nuclear power plants by treating radioactive metal waste to the level below free release criteria. The mobile HIFU decontamination equipment used in the demonstration can be operated anywhere where water is supplied, including controlled area in nuclear power plants, and is expected to be used widely for decontamination and free release of metal radioactive wastes.