• 한국지하수토양환경학회지:지하수토양환경
• /
• 제17권5호
• /
• pp.40-48
• /
• 2012

In this study, economic analysis of five desalination technologies for saline agricultural land was carried out. The analysis was comprehensively evaluated by calculating changes in crop production and benefit/cost (B/C) ratio. The analysis of crop production was in the order of tomato > cucumber > a (musk) melon > watermelon > cabbage, and economical efficiency for desalination technology was in the order of soil exchange > soil addition > electrokinetics > under-drainage > subsoil reversal. In cost benefit analysis, B/C ratio was in the order of under-drainage > soil exchange > electrokinetics > soil addition > subsoil reversal, and all desalination technologies used in this study have the ratio higher than 1, which means economical efficiency was high. Based on the net production considering B/C ratio, the general economic analysis was exactly order from that of crop production analysis. As a result, economical efficiency of soil exchange was highest, and economical efficiency of soil addition and electrokinetic was relatively higher than others.

• 산업경영시스템학회지
• /
• 제32권3호
• /
• pp.29-39
• /
• 2009

In an environment of global competition, the success of a manufacturing corporation is directly related to how it plans and executes production in particular as well as to the optimization level of its process in general. This paper proposes a production planning algorithm for the Multi-Level, multi-item Capacitated Lot Sizing Problem (MLCLSP) in supply chain network considering back-order. MLCLSP corresponds to a mixed integer programming (MIP) problem and is NP-hard. Therefore, this paper proposes an effective algorithm, GRHS (GRASP-based Rolling Horizon Search) that solves this problem within reasonable computational time and evaluates its performance under a variety of problem scenarios.

• 산업경영시스템학회지
• /
• 제24권66호
• /
• pp.79-90
• /
• 2001

In this paper, production information management systems for global manufacturing enterprises is discussed. Three basic technologies to implement the system such as networking, database, and H/W interface technology are investigated, and a web based prototype systems integrating order and production information is developed with two server computers and a educational FMS. A MMI s/w is engaged in interfacing and real-time monitoring of FMS and an intranet is used for communication between the servers and clients.

• 복식
• /
• 제65권1호
• /
• pp.46-60
• /
• 2015

This study analyzed the process of development and verification of standards through the competency analysis of fashion accessories products in the development of 'National Competency Standards'(NCS), which was carried out in 2013 for the fashion industry. The NCS for fashion accessories production was developed through three Focus Group Interviews (FGIs) and fashion accessories production was defined as "the process of design, development and manufacture intended to produce items that improve the degree of completion of fashion products that are produced from textile fabric, knitted fabric, leather and other materials such as bags, belts, hats, gloves, scarves, neckties and socks with the exception of clothes". The competency unit for fashion accessories production was analyzed in 11 categories: development of design; development of materials; production of prototype samples; calculation of cost; determination of mass production model and price; planning of main manufacture process; ordering of materials; planning for mass production; preparation for mass production; mass production; and inspection of completed products, and the verification was carried out on development outcomes through a survey carried out of on-site personnel. This study recommends the following direction for future improvements based on an analysis of the development process of the NCS for fashion accessories production. First, future development of standards should first provide a rational category system for each area of fashion good production based on the production process, which should be followed by a detailed competency survey. Second, in order to ensure a more efficient verification survey, an expert for each competency unit should be designated for the develop standard to induce a more sincere response. Also the questionnaire should require supplementation in order to collect the various additional opinions of experts of the field. Finally, this study concludes that it is urgent to procure an education infrastructure and specialized professors in order to apply the competency standard for fashion accessories production to the education sector. This study also concludes that the government will be required to provide systematic and consistent support aimed at supplementing development and forming a firm collaborative working environment for the industry and academia in order to improve the current education environment and build a more field-oriented education environment.

• 한국경영과학회:학술대회논문집
• /
• 대한산업공학회/한국경영과학회 1995년도 춘계공동학술대회논문집; 전남대학교; 28-29 Apr. 1995
• /
• pp.476-486
• /
• 1995

In this paper, an attempt has been made to revise Raafat' s(1985) results on an inventory model for decaying raw materials and the finished product at a constant rate which was based on Goyal's integrated inventory model for a single product system. This paper is concerned with scheduling the frequencies of order quantity of several different raw materials on a production inventory model. The purpose of this paper is to present a simple method of deciding the frequencies of order quantity of raw materials, in the sense of minimizing the average total cost of the system. We describe on iterative procedure for directly determining near optimal frequencies of order quantity for the raw materials and the associated fundamental cycle time which can be used for constructing the production duration of the finished product. In cases where feasible schedules cannot be constructed using the values from the iterative procedure, the procedure provides a basis for changing the order quantity frequencies and the fundamental cycle time to obtain feasible schedules. An example is given to illustrate the derived results.

• 한국의류학회지
• /
• 제26권11호
• /
• pp.1582-1592
• /
• 2002

The purpose of this study is to suggest production planning model for women's apparel manufacturer, which are relevant to the situation of Korean clothing industry. The research was based on simulation method. The basic model for the simulation was developed based on the empirical data from six production fm. After verifying the basic model, low alternative production plans went through trial run. In order to suggest the application of these alternative production plans for various style numbers and lot sizes, the simulation results were compared in terms of product efficiency and product cost. The four alternative plans were as follows: 1. The first alternative was to spread out work loads among workers in order to resolve bottlenecks in work flow. So this was suited to manufacturers that had constant production without regard to changing seasons. 2. The second alternative was to merge the skirt and trouser production, which require less work load, in one line. In this line, a few machine was justified by production improvement. It was suited to cases which producted various style suits. The third and fourth alternative were using another subcontractor for assembling inner shell garments. These was compatible in manufacturers which had to product more styles and sizes of trousers and skirts than those of upper garments. 3. The third alternative was to reassign the same workers in production line. Thus, production was increased. 4. The fourth alternative was to except two worker in production line, so expenses of worker's wage was decreased. The four alternatives could be one of the cost effective manufacturing plans according to manufacturer situations.

• International Journal of Naval Architecture and Ocean Engineering
• /
• 제12권1호
• /
• pp.20-37
• /
• 2020

In this paper, we propose a simulation method based on backward simulation and process-oriented simulation to take into account the characteristics of shipbuilding production, which is an order-based industry with a job shop production environment. The shipyard production planning process was investigated to analyze the detailed process, variables and constraints of mid-term production planning. Backward and process-centric simulation methods were applied to the mid-term production planning process and an improved planning process, which considers the shipbuilding characteristics, was proposed. Based on the problem defined by applying backward process-centric simulation, a system which can conduct Discrete Event Simulation (DES) was developed. The developed mid-term planning system can be linked with the existing shipyard Advanced Planning System (APS). Verification of the system was performed with the actual shipyard mid-term production data for the four ships corresponding to a one-year period.

• 산업공학
• /
• 제6권2호
• /
• pp.53-65
• /
• 1993

This paper deals with the development of a software module for production planning and scheduling activities of an existing Flexible Machining and Assembly System (FMAS). The Production Planning Module uses the hierarchical and sequential scheme based on "divide and conquer" philosophy. In this module, routes are determined based on the production order, orders are screened, tools are allocated, and order adjustments are executed according to the allocated tools. The Scheduling Module allocates the resources, determines the task priority and the start and completion times of tasks. Re-scheduling can be done to handle unforeseen situations such as lumpy demands and machine breakdowns. Since all modules are integrated with a central database and they interface independently, it is easy to append new modules or update the existing modules. The result of this study is used for operating the real FMAS consisting of a machining cell with 2 domestic NC machines and a part feeding robot, an assembly cell with a conveyor and 3 robots, an inspection cell, an AGV, an AS/RS, and a central control computer.

• Environmental Engineering Research
• /
• 제24권4호
• /
• pp.559-565
• /
• 2019

In order to alleviate the environmental pressure caused by production process of thermal power plants, the application of cleaner production is imperative. To estimate the implementation effects of cleaner production in thermal plants and optimize the strategy duly, it is of great significance to take a comprehensive evaluation for sustainable development. In this paper, a hybrid model that integrated the analytic hierarchy process (AHP) with least squares support vector machine (LSSVM) algorithm optimized by grid search (GS) algorithm is proposed. Based on the establishment of the evaluation index system, AHP is employed to pre-process the data and GS is introduced to optimize the parameters in LSSVM, which can avoid the randomness and inaccuracy of parameters' setting. The results demonstrate that the combined model is able to be employed in the comprehensive evaluation of the cleaner production in the thermal power plants.

• 지능정보연구
• /
• 제27권1호
• /
• pp.177-190
• /
• 2021

4차 산업혁명 기술의 발전으로 사람이 처리하지 못하는 부분을 기계학습 등 인공지능 기법을 활용하여 개선해 보려는 노력이 확대되고 있다. 주문형 생산 기업에서도 주문에 대한 총생산시간을 예측하여 납기 지연 등의 기업 리스크를 줄이고자 하나 주문마다 총생산시간이 모두 달라 이를 예측하는데, 어려움을 겪고 있다. 주문 처리량 증대, 주문 총비용 절감을 위해 효율성이 가장 낮은 영역을 찾아 그 영역을 강화하는 TOC(Theory of constraints) 이론이 개발되었으나 총생산시간 예측은 제시하지 못하였다. 주문생산은 고객의 다양한 요구로 인해 주문마다 그 특성이 모두 다르므로 개별적인 주문의 총생산시간을 사후에 측정할 수는 있으나 사전 예측을 하기는 어렵다. 기존 주문의 이미 측정된 총생산시간도 모두 달라 표준 시간으로 활용할 수 없는 한계성이 있다. 이에 따라 경험이 많은 관리자는 시스템의 이용보다는 감에 의존하고 있고, 경험이 부족한 관리자는 간단한 관리지표(예, 원재료가 파이프이면 총생산시간 60일, 철판이면 총생산시간 90일 등)를 사용하고 있다. 불완전한 감이나 지표를 기초로 하여 작업 지시를 너무 빨리하면 정체가 발생하여 생산성이 저하되고, 너무 늦게 하면 긴급 처리로 인해 생산비용이 증가하거나 납기를 지키지 못하는 경우가 발생한다. 납기를 지키지 못하면 지체상금을 배상해야 하거나 영업, 수금 등의 부문에 악영향을 미친다. 본 연구에서는 이러한 문제를 해결하기 위하여 주문생산시스템을 운영하는 기업의 신규 주문 총생산시간을 추정하는 기계학습 모델을 찾고자 한다. 기계학습에 활용된 자료는 수주, 생산, 공정 실적을 사용한다. 그리고 총생산시간의 추정에 가장 적합한 알고리즘으로 OLS, GLM Gamma, Extra Trees, Random Forest 알고리즘 등을 비교 분석하고 그 결과를 제시하고자 한다.