This study addresses the optimal design methodology for switching between active electronically scanned array (AESA) radar operating modes to easily select the necessary information to reduce pilots' cognitive load and physical workload in situations where diverse and complex information is continuously provided. This study presents a procedure for defining a hidden Markov chain model (HMM) for modeling operating mode changes based on time series data on the operating modes of the AESA radar used by pilots while performing mission scenarios with inherent uncertainty. Furthermore, based on a transition probability matrix (TPM) of the HMM, this study presents a mathematical programming model for proposing the optimal structural design of AESA radar operating modes considering the manipulation method of a hands on throttle-and-stick (HOTAS). Fighter pilots select and activate the menu key for an AESA radar operation mode by manipulating the HOTAS’s rotary and toggle controllers. Therefore, this study presents an optimization problem to propose the optimal structural design of the menu keys so that the pilot can easily change the menu keys to suit the operational environment. K
본 연구는 테이블 탑 보드게임 개발 방법론인 CDR 모델을 제안하여 보드게임 개발과정에서의 어려움을 일 부 해소하고 나아가 디자이너가 개발 경험을 지속할 수 있는 토대를 마련하는 것이 목적이다. 이를 위해 보 드게임 개발 방법론인 CDR 모델을 설계하고 보드게임 개발 경험이 있는 전문가 패널 15명을 대상으로 인터 뷰를 진행하였다. 연구 결과 CDR 모델이 기존의 개발 방법론보다 체계적인 개발이 가능하도록 설계되어 개 발 시 단계별 작업 내용을 확인하고, 오류를 줄이면서 누락내용 없이 개발이 가능한 것으로 나타났다. 본 연 구에 의한 CDR 모델을 통해 보드게임을 만들고자 하는 디자이너는 보드게임을 디자인하는 데 있어서 가장 중요한 게임요소와 그것을 어떻게 부각할지에 대한 고민을 해결하고 개발을 지속할 수 있는 토대를 마련하 는 데 도움이 될 것으로 기대한다.
Since the first operation of the Gori No. 1 nuclear power plant in Korea was started to operate in 1978, currently 24 nuclear power plants have been being operated, out of which 21 plants are PWR types and the rest are CANDU types. About 30% of total electricity consumed in Korea is from all these nuclear power plants. The accumulated spent nuclear fuels (SNFs) generated from each site are temporarily being stored as wet or dry storage type at each plant site. These SNFs with their high radiotoxicity, heat generating, and long-lived radioactivity are currently the only type of high-level radioactive waste (HLW) in Korea, which urgently requires to be disposed of in deep geological repository. Studies on disposal of HLW in various kind of geological repositories have been carried out in such countries as Sweden, Finland, United States, and etc. with their own management policies in consideration of their situations. In Korea long-term R&D research program for safe management of SNF has also been conducted during last couple of decades since around 1997, during which several various type of disposal concepts for disposal of SNFs in deep geological formations have been investigated and developed. The first concept developed was KAERI Reference Disposal System (KRS) which is actually very much similar to Swedish KBS-3, a famous concept of direct disposal of SNF in stable crystalline rock at a depth of around 500 m which has been regarded as one of the most plausible method worldwide to direct disposal of SNF. The world first Finnish repository will be also this type. Since the characteristics of SNF discharged from domestic nuclear reactors have been changed and improved, and burnup has sometimes increased, a more advanced deep geological repository system has been needed, KRS-HB (KRS with High Burnup SNF) has been developed and in consideration of the dimensions of SNFs and the cooling period at the time point of the disposal time, KRS+, a rather improved disposal concept has also been subsequently developed which is especially focused on the efficient disposal area. Recently research has concentrated on rather advanced disposal technology focused on a safer and more economical repository system in recent view of the rapidly growing amount of accumulated SNF. Especially in Korea the rock mass and the footprint area for the repository extremely limited for disposal site. Some preliminary studies to achieve rather higher efficiency repository concept for disposal of SNF recently have already been emphasized. Among many possible ones for consideration of design for high-efficiency repository system, a double-layered system has been focused which is expected to maximize disposal capacity within the minimum footprint disposal area. Based on such disposal strategy a rather newly designed performance assessment methodology might be required to show long-term safety of the repository. Through the study some prerequisites for such methodological development will be roughly checked and investigated, which covers FEP identification and pathway and scenario analyses as well as preliminary conceptual modeling for the nuclide release and transport in near-field, far-field, and even biosphere in and around the conceptual repository system.
Surge pressure is created by rapid change of flow rate due to operation of hydraulic component or accident of pipeline. Proper control of surge pressure in distribution system is important because it can damage pipeline and may have the potential to degrade water quality by pipe leakage due to surge pressure. Surge relief valve(SRV) is one of the most widely used devices and it is important to determine proper parameters for SRV’s installation and operation. In this research, determining optimum parameters affecting performance of the SRV were investigated. We proposed the methodology for finding combination of parameters for best performance of the SRV. Therefore, the objective function for evaluate fitness of candidate parameters and surge pressure simulation software was developed to validate proposed parameters for SRV. The developed software was integrated into genetic algorithm(GA) to find best combination of parameters.
Zero-waste is sustainable development for ensuring continuous interactions with the environment as well as for the next generations, while expanding across industries. Zero-waste fashion design does not necessarily mean that we should stop making clothes in order to reduce waste, but we consider the social values of sustainability regarding the environment, humans, and profit. In particular, in the pre-use stage of zero-waste fashion design, fashion designers play critical roles. The purpose of this study is to develop a methodology for the realization of zero-waste fashion design through establishing the typology of zero-waste pattern making (ZWPM) as well as exploring the practical implications of zero-waste fashion design. For the realization of zero-waste fashion design that draws from pattern-making principals, this study categorizes zero-waste fashion design into zero-waste pattern cutting (ZWPC) and non-pattern cutting (NPC). ZWPC is based on drafting patterns on a piece of fabric, which can enable the sharing of patterns and processes, while NPC requires little- or non- cutting/sewing in optimizing a piece of fabric, bringing the possibility of creating indefinite forms. ZWPC is sub-categorized into tailored and non-tailored, and NCP into draped and folded. Then, by implementing the typology in undergraduate design programs, this study tests and completes the design methodology for the realization of zero-waste fashion design.
원전해체시장이 본격적으로 도래함에 따라 그에 따른 기술연구가 부각되고 있다. 그러한 기술 중 방사선 제염은 직접적인 원전해체 과정 중 가장 초반에 행해지는 작업으로 현장 근로자의 안전확보 및 폐기물 양 감소를 위해 수행되는 중요한 작업 이다. 제염을 통해 폐기물 표면에 존재하는 방사선 물질을 제거하게 되는데 해체에 적용되는 제염기술은 보다 강한 매개체 를 사용하거나 개선된 설비를 활용하여 표면층 제거 정도가 일반적인 제염보다 훨씬 크다. 따라서 제염 계획 수립시 다양 한 관점에서 분석 방법이 필요하다. 본 연구에서는 제염기술 선정을 위해 고려해야 할 요인을 설명하였으며, 대표적인 제염 기술 사례 분석을 통해 실제 기술 수행을 위해 원전 설비 내 제염 아이템 선정 및 제염 장비 활용을 위해 검토해야 할 사항 을 제시하였다.
District Metered Area (DMA) construction is one of the most cost effective alternatives for management of water loss (i.e., water leakage) and energy consumption (i.e., water pressure) in water distribution systems. Therefore, it’s being implemented to numerous new and existing water distribution systems worldwide. However, due to the complexity of water distribution systems, especially large-scale and highly looped systems, it is still very difficult to define the optimal boundary of DMAs considering all the aspects of water distribution system management requirements. In this study, a DMA design methodology (or a DMA design model) was developed with Geographic Information Systems (GIS) and hydraulic distribution system model to determine the optimal DMA boundary.
The determining the appropriate dosage of coagulant is very important, because dosage of coagulant in the coagulation process for wastewater affects removing the amount of pollutants, cost, and producing sludge amount. Accordingly, in this study, in order to determine the optimal PAC dosage in the coagulation process, CCD (Central composite design) was used to proceed experimental design, and the quadratic regression models were constructed between independent variables (pH, influent turbidity, PAC dosage) and each response variable (Total coliform, E.coli, PSD (Particle size distribution) (‹10 μm), TP, PO4-P, and CODcr) by the RSM (Response surface methodology). Also, Considering the various response variables, the optimum PAC dosage and range were derived. As a result, in order to maximize the removal rate of total coliform and E.coli, the values of independent variables are the pH 6-7, the influent turbidity 100-200 NTU, and the PAC dosage 0.07-0.09 ml/L. For maximizing the removal rate of TP, PO4-P, CODcr, and PSD(‹10 μm), it is required for the pH 9, the influent turbidity 200-250 NTU, and the PAC dosage 0.05-0.065 ml/L. In the case of multiple independent variables, when the desirable removal rate for total coliform, E.coli, TP, and PO4-P is 90-100 % and that for CODcr and PSD(‹10 μm) is 50-100 %, the required PAC dosage is 0.05-0.07 ml/L in the pH 9 and influent turbidity 200-250 NTU. Thus, if the influent turbidity is high, adjusting pH is more effective way in terms of cost since a small amount of PAC dosage is required.
Response surface methodology (RSM) based on a Box-Behnken Design (BBD) was applied to optimize the thermal-alkaline pre-treatment operating conditions for anaerobic digestion of flotation scum in food waste leachate. Three independent variables such as thermal temperature, NaOH concentration and reaction time were evaluated. The maximum methane production of 369.2 mL CH4/g VS was estimated under the optimum conditions at 62.0°C, 10.1% NaOH and 35.4 min reaction time. A confirmation test of the predicted optimum conditions verified the validity of the BBD with RSM. The analysis of variance indicated that methane production was more sensitive to both NaOH concentration and thermal temperature than reaction time. Thermal-alkaline pretreatment enhanced the improvement of 40% in methane production compared to the control experiment due to the effective hydrolysis and/or solubilization of organic matters. The fractions with molecular weight cut-off of scum in food waste leachate were conducted before and after pre-treatment to estimate the behaviors of organic matters. The experiment results found that thermal-alkaline pre-treatment could reduce the organic matters more than 10kD with increase the organic matters less than 1kD.
오늘날 대 산업분야는 과학 기술의 진보에 따라 비약적인 기술발달을 이루었다. 따 라서, 고객이 요구(Needs)하는 다양한 기능을 구현하기 위해 상당수 부분을 소프트웨 어 중심으로 달성하고 있다. 이렇듯, 과거의 하드웨어 중심의 자동차와 달리 소프트웨 어 중심의 기능 구현이 이행되고 있는 실정이다. 이렇다 보니, 시스템이 보다 복잡해 짐에 따라 시스템을 설계하고 제어하는데 있어서 상당한 어려움이 따르고 있다. 따라 서, 유럽에서는 자동차 분야의 전자제어 장비로 인한 기능안전을 달성하기 위해 ISO26262라는 국제표준을 제정하였다. 국제표준의 제정에 따라 국내 자동차 산업은 차량 시스템을 설계하는데 있어서의 노력, 뿐만 아니라, 기능안전이라는 안전부분을 대비해야하는 상황에 직면하게 되었다. 본 연구에서는 자동차 시스템의 상위 수준의 설계인 개념설계 단계에서 FMEA를 통한 안전성 활동 반영을 통한 하나의 단일화된 개발 방법론을 본 연구를 통해 제시하고자 한다. 따라서, 본 연구를 기반으로 향후 추가 연구를 수행한다면, 국내 자동차 산업, 뿐만 아니라, 대형복합 안전 중시 시스템 으로 확대하여 설계단계에서 안전성을 동시 고려한 시스템 설계 신뢰성 확보를 위해 도움이 될 것으로 기대 된다.
Modern systems development becomes more and more complicated due to the need on the ever-increasing capability of the systems. In addition to the complexity issue, safety concern is also increasing since the malfunctions of the systems under development may result in the accidents in both the test and evaluation phase and the operation phase. Light rail transit(LRT) with passenger capacity between bus and subway is driven by an unmanned control, so safety issues of LRT in emergency shall be considered more carefully than other rolling stock. Modern railway system is a complex system and many actions in emergency are required. In this view, interoperability approach is effective to identify the related elements in emergency. In this paper, we propose the method to generate the fire response scenario of unmann ed LRT based on the outputs of systems engineering architecture design methodology. The proposed method is could be contributed to establish more reliable and applicable fire response scenario.
In order to suggest the methodology for improving the equity of flow distribution in open channel with multiple outlet, CFD simulations were carried out for actual scale distribution channel being operated in domestic G_WTP(Water Treatment Plant). Also, before and after installing the longitudinal multi hole(diameter=250 mm, 116 holes) baffle suggested by this research, turbidity measurements data were collected for evaluating the effects of hydraulic modification for inlet flow equity. From the both results, total turbidity of settled water was lowered by 30 % and equity of flow distribution was improved about 60 % compared with before hydraulic structure modification.
본 연구는 포스트텐션 콘크리트 포장(PTCP: Post-Tensioned Concrete Pavement) 공법의 Gap Slab 설계 방안을 구축하기 위하여 수행되었다. Gap Slab은 특징에 따라 Unbonded, Half Bonded, Bonded 방식으로 구분하여 고려하였다. 먼저 각 Gap Slab 방식에 따라 환경하중이 작용할 때 슬래브의 컬링에 의해 발생하는 인장응력을 산정하였으며, 차륜하중에 의한 응력은 단축과 복축 하중을 모두 고려하여 산정하였다. 환경 및 차륜하중에 의해 발생하는 혼합 최대 인장응력을 구하여 허용인장응력과의 비교를 통하여 Gap Slab에 도입하는 긴장량을 산정하는 방법을 제시하였다. Unbonded 방식은 Gap Slab 만을 고려하여 응력 분포를 분석함으로써 긴장량을 설계할 수 있으나, Half Bonded 및 Bonded 방식은 PTCP의 전체 슬래브의 거동을 분석함으로써 적절한 설계가 가능하며 이에 대한 방법론을 제시하였다.
Today, many of communication methods based on print media traditionally has moved to the internet. As increase of interest in internet business, effective web site design is needed. While the researches for the evaluation of completed web site are increased, that of web site design procedures are rare. In the design process occur various problems : rework, delay, etc.. In this paper are presented the improved procedures of web site design using 6 sigma methodology. The main object of this study is to introduce an empirical study on DIDOV.