• 대한산업공학회지
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• 제33권2호
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• pp.246-253
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• 2007

All of the machines in a production line can be classified into bottleneck and non-bottleneck machines. A bottleneck is a resource whose capacity limits the throughput of the whole production facility. This paper addresses a batch sizing problem at the bottleneck machine. Traditionally, most batch sizing decisions have been made based on the EOQ (economic order quantity) model where setup and inventory costs are considered while throughput rate is assumed to be given. However, since batch size affects the capacity of the bottleneck machine, the throughput rate may not be constant. As the batch size increases, the frequency of the setup decreases. The saved setup time can be transferred to processing time, which results in higher throughput. But, the larger batch size may also result in longer lead time and larger WIP inventory level. This paper presents an alternative method to determine batch size at the bottleneck machine in a manufacturing line. A linear search algorithm is introduced to find optimal throughput rate and batch size at the same time. Numerical examples are provided to see how the proposed method works and to investigate the effects of some parameters.

• 산업융합연구
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• 제21권9호
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• pp.11-21
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• 2023

그동안 CG제작공정의 효율성을 향상시키기 위한 많은 연구가 있었지만, 작업 중간에 결과물의 확인이 어렵고 렌더링 타임에 많은 시간이 소요된다는 문제점을 극복하기는 쉽지 않았다. 그러나 최근 실시간으로 결과물의 확인이 가능한 언리얼 라이브 링크의 활용 가능성이 커지면서 제작공정의 효율성 향상에 대한 기대감이 높아지고 있다. 이에 이 연구에서는 언리얼 라이브 링크를 이용한 3D 애니메이션 제작공정의 효율성을 분석하였다. 이를 위해 마야로 모델링, 리깅, 애니메이션, 레이아웃 작업을 하고 언리얼 라이브 링크를 통해 언리얼 엔진에서 최종 아웃풋 이미지 시퀀스를 도출하는 방식으로 3D 애니메이션을 제작하였다. 그리고 3D 소프트웨어 자체에서 최종 아웃풋 이미지 시퀀스를 을 도출하는 기존의 제작공정과 본 제작공정의 차이점을 비교 분석하였다. 분석 결과 전통적인 3D 애니메이션의 제작공정과 달리 높은 퀄리티의 최종결과물을 보여주는 뷰포트 화면을 통해 작업을 진행함으로써 실시간으로 최종 작업 결과물을 확인하는 것이 가능하였으며, 실시간 화면 캡쳐를 통해 최종결과물을 도출함으로써 작업의 효율성이 극대화되는 것을 알 수 있었다. 최근 3D 애니메이션과 영화 산업현장에서 게임 엔진을 활용하는 사례가 점차 늘고 있는데, 언리얼 라이브 링크를 활용할 경우 작업의 효율성이 매우 극대화될 것으로 예상된다.

• 대한영양사협회학술지
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• 제19권3호
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• pp.236-252
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• 2013

The purpose of this study was to assess the microbiological quality of home-delivered meals during production and delivery for children from low-income families. Production flows from a facility in Seoul that provides home-delivered meals were analyzed and the time-temperature of the food was measured. Microbiological assessment was performed for the production environment, personal hygiene, and food samples at each production and delivery step based on the process approach. It took 2 hours or longer from completion of production to meal delivery. An aerobic colony count (ACC) and coliform were not detected at knives, cutting boards, and dish towels. However, ACC (at pre-preparation, preparation, and packing areas) and coliform (at the preparation area) were detected on the hands and gloves of employees. Air-borne bacterial counts varied according to day and preparation area (ND~6 CFU/plate/15 min). Food temperatures, on the completion of production and meal delivery, fell into temperature danger zones. ACC and coliform counts of raw ingredients did not decrease after pre-preparation (washing and sanitizing) for menus involving food preparation with no cook step. ACC decreased after cooking step for menus of food preparation with cook step, but the ACC of the stir-fried and seasoned dried filefish fillet on the completion of cooking was too numerous to count due to improper heating. The ACC of seasoned young Chinese cabbages (a menu with complex food preparation) increased during delivery (from 2.5 log CFU/ml to 5.0 log CFU/ml). This qualitative assessment of foodborne pathogens revealed that B. cereus was detected in vegetable and meat product menus. These results suggest time-temperature control is necessary during production and delivery and management guidelines during production of home-delivered meals are provided for safe production.

• Industrial Engineering and Management Systems
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• 제10권3호
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• pp.197-202
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• 2011

In traditional production lines, such as assembly lines, each worker is usually assigned to a particular fixed work, and decreasing the task to master the assigned work is valuated. However, when an imbalance exists between workers' speeds, if a worker delays the overall work in the production line, the production rate of the particular line will also decrease. To avoid this problem, the "Self-Balancing Production Line" was introduced. In this type of production line, each worker is assigned work dynamically, and when specific conditions are satisfied, production remains balanced. Characteristics of these lines that can be preempted at any place have already been analyzed by some researchers. A previous paper examined the situation in which only a single worker can process one machine and cannot preempt processing, and the improved policy of an ordinary selfbalancing production line, which specifies which stations workers can process and how workers can behave. This policy achieveda high production rate with only four stations and two workers (Buzacott, 2002). In that paper, worker processing stations and the behavior of a specific worker were limited, andthe paper focused only on specific stations and workers. Therefore, it is not applicable to any worker sequence. In this paper, we focus on other ways to decrease cycle time. In this kind of line, a worker processes at his or her speed. Therefore, if a worker is assigned stations according to his or her speed, the line can decrease cycle time. To do so, we relax the assumptions of this type of line and set a new condition. Under these conditions, we compare our results to the results of previous papers.

• 산업경영시스템학회지
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• 제38권4호
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• pp.149-158
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• 2015

Up-to-date manufacturing companies have faced a market-driven environment of pull production order. There should be a difference in operating manufacturing resources according to the type, quantity, and delivery time of manufactured products, because the process situation in pull production is changed by customer orders. And it should be taken into account from the stage of preparing for production such as process design and the placement and utilization of manufacturing resources. However, the feasibility of production plans is limited because most of small manufacturing businesses make production/supply plan of the parts and products assuming that equipment abilities in scheduling is sufficient without managing process standard information systemically. In this study, a discrete event simulation system based on BOM (bill of material), that is F-OPIS (online productivity innovation system), is introduced and a case study on application of the system leading to improving productivities is presented. F-OPIS deals with a decision-problem on production management and it is specialized for small-and- medium sized manufacturing companies. The target company of this case study is a typical small-and-medium sized manufacturing company in Korea, that produces various machined parts. The target company adopts make-to-stock production management to prevent tardy delivery because of fluctuations in demand. Therefore, it is required to apply an efficient inventory control solution for improving productivities. In this paper, based on the constraints of working capacity of manufacturing resources, the bottleneck process is analyzed as production conditions are changed. Consequently, an improvement plan is proposed, that eventually enhances overall utilization rates of resources in the bottleneck process and reduces overall production lead-time and inventory level.

• Journal of information and communication convergence engineering
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• 제7권4호
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• pp.459-464
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• 2009

This paper presents a production information monitoring system as an infrastructure of CIM system in footwear industry. The system is composed of hardware devices of terminal, communication converter, line controller and software for manufacturing processes. A terminal like a scanner is used for shop floor data input and a line controller is used to link between terminal and server. LAN and RS485 are used for connecting hardware components and deliver their information mutually. In the system, real time production information is acquired from information resources such as group of uppers and soles. The collected production information is delivered to a line controller and analyzed. Server receives information from line controller and machines for production management. Production planning information that is machined in the server is delivered to the shop floor and used for the production management of work in process, and used for improvement of productivity in a footwear production company. The implementation of the developed system shows the effectiveness of the system.

• 디지털산업정보학회논문지
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• 제9권4호
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• pp.167-175
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• 2013

This study is the process of making high-definition TV broadcast color correction affects the end result comparison is focus on implement through study. In the production process and the impact on the color Correction in the video as an study for UHD, 4K, 6K video production workflow improvement of an effective program in the present and time and cost in the post production process, color correction for the final video through the production and overcome the failure of further in-efficient color correction study will help you to solve the problem. This study is the color changes over the course of the final video to see how much influence color correction of post-production. Color correction using a program of courses in Visual quality, regularly presented the possibility to retain and make on high definition video production post-production process for color correction method is utilized as the basis of study.

• 산업경영시스템학회지
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• 제39권3호
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• pp.147-155
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• 2016

Industry 4.0's goal is the 'Smart Factory' that integrates and controls production process, procurement, distribution and service based on the fundamental technology such as internet of the things, cyber physical system, sensor, etc. Basic requirement for successful promotion of this Industry 4.0 is the large supply of semiconductor. However, company I who produces dicing blades has difficulty to meet the increasing demand and has hard time to increase revenue because its raw material includes high price diamond, and requires very complex and sensitive process for production. Therefore, this study is focused on understanding the problems and presenting optimal plan to increase productivity of dicing blade manufacturing processes. We carried out a study as follows to accomplish the above purposes. First, previous researches were investigated. Second, the bottlenecks in manufacturing processes were identified using simulation tool (Arena 14.3). Third, we calculate investment amount according to added equipments purchase and perform economic analysis according to cost and sales increase. Finally, we derive optimum plan for productivity improvement and analyze its expected effect. To summarize these results as follows : First, daily average blade production volume can be increased two times from 60 ea. to 120 ea. by performing mixing job in the day before. Second, work flow can be smoother due to reduced waiting time if more machines are added to improve setting process. It was found that average waiting time of 23 minutes can be reduced to around 9 minutes from current process. Third, it was found through simulation that the whole processing line can compose smoother production line by performing mixing process in advance, and add setting and sintering machines. In the course of this study, it was found that adding more machines to reduce waiting time is not the best alternative.

• Asian-Australasian Journal of Animal Sciences
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• 제12권7호
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• pp.1040-1048
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• 1999

Four ruminally fistulated crossbred $(Sahiwal{\times}Holstein\;Friesan)$ adult (~6 yr.) cattle of about $318{\pm}16kg$ body weight were randomly assigned in an experiment based on $4{\times}4$ latin square design to study the effect of different level of barseem (Trifolium alexendrinum) supplementation to wheat straw based diet on intake, digestion, VFA production, eating behaviour and passage rate. Four dietary treatments were wheat straw ad lib. (I), supplementation to wheat either 15(II), 30(III) or 45(IV)% of berseem. Mean total volatile fatty acids (TVFA) concentration in rumen liquor was 58.45, 66.14, 77.92 and 78.64 mmol/l. TVFA concentration in rumen liquor increased significantly (p<0.01) with increased level of berseem supplementation upon 30% level of breseem. Two peaks of TVFA concentration was observed at 4 and 8 h post feeding. Brseem supplementation showed no significant effect on daily time spent for eating, ruminating or idling, chews per minute or number of rumination boli ingested per minute. Time spent for eating and ruminating one kg neutral detergent fibre (NDF) was significantly (p<0.05) less in breseem supplemented groups. Animals in groups I, II, III and IV consumed 26, 34, 47 and 57% of DM within 1st 4 h and 64, 70, 70 and 77% of total DM within 1st 8 h of offering. All the animals consumed more than 90% of their DMI within 12 h. Active period of rumination was observed 8h post feeding reached the peak at 16 h post feeding, then declined and animals spend considerable time idling in last 4 h of 24 h feeding cycle. Berseem supplementation showed no significant effect on eating and rumination time. It is concluded that berseem supplementation upon 30% increases the efficiency of chewing during eating and rumination, which results in increase intake and TVFA production and nutrient digestibility.

• 한국컴퓨터정보학회논문지
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• 제19권12호
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• pp.171-175
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• 2014

NP-완전인 상자 포장 문제의 일종인 사탕수수 설탕 생산 문제에 대해, Gu$\acute{e}$ret et al.은 $O(m^4)$ 수행 복잡도의 선형계획법으로 해를 얻고자 하였다. 반면에, 본 논문에서는 사탕수수 설탕 생산 문제는 다항시간으로 해를 찾아가는 규칙이 존재한다는 가정하에, 최대 손실량을 가진 로트를 우선 생산하는 탐욕 규칙인 O(mlogm)의 다항시간 복잡도로 해를 구할 수 있는 알고리즘을 제안하였다. 제안된 방법은 설탕 함유량 손실 기울기를 내림차순으로 정렬한 후, 해당 슬롯 생산능력의 로트들을 선택하는 방법과 해당 슬롯에서 수명을 다하는 로트들과 마지막으로 선택된 로트들과 교환하는 방법을 적용하였다. 실험 결과, 제안된 알고리즘은 사탕수수 설탕 생산 문제에 대해 선형계획법의 $O(m^4)$를 O(mlogm) 으로 단축시키면서도 보다 좋은 결과를 얻었다.