• Journal of Korean Institute of Industrial Engineers
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• v.30 no.2
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• pp.159-164
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• 2004

Lot-streaming is the process of splitting a job (lot) into a number of smaller sublots and then scheduling these sublots in order to accelerate the completion of jobs in a multi-stage production system. Anew genetic algorithm (NGA) is proposed for an-job, m-machine, equal-size sublot lot-streaming flow shop scheduling problem with delivery windows in which the objective is to minimize the mean weighted absolute deviation of job completion times from due dates. The performance of NGA is compared with that of an adjacent pairwise interchange (API) method and the results of computational experiments show that NGA works well for this type of problem.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.11a
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• pp.181-183
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• 2011

This study was carried out about construction management plan to reduce water leakage of underground parking lot in the apartment housing. To minimize effect of upper working load, installation position of jack support and paving with rubble on the top of underground parking lot were studied. By calculation shrinkage strain of underground parking lot scale, water leakage risk in design of level difference was studied. In this study, the basic data about construction management was provided to reduce water leakage of underground parking lot in the apartment housing.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.17 no.32
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• pp.177-186
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• 1994

Economic Lot size decision is studied on this thesis foe the muti-product small batch production system. Even though economic lot size decision has been studied for the MRP system. this could be applied at the industry under the multi-product small batch production system because of very complicate and manager's lack of understand. Therefore, this technique is applied at the industry in order to minimize ordering cosy based on optimal quantity and period, and holding cost according to optimize inventory level under the muti-product small batch production system. After that, lot size decision technique is compared with lot size decision technique which has been used for analyzing and emphasizing productivity

• Journal of Korean Society for Quality Management
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• v.18 no.1
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• pp.65-76
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• 1990

A lot-sizing model for multi-stage MRP systems is proposed, in which known demands must be satisfied. In this model, an approach with considerations of initial inventory and limited production capacity is involved. Most of the studies on the lot-sizing techniques for multi-stage material requirement planning systems have been focused upon two basic approaches. One approach is to develope an algorithm yielding an optimal solution. Due to the computational complexity and sensitivity of the optimal solution to the problem of lot sizing, heuristic approaches are often employed. In this paper, the heuristic approach is used by sequential application of a single-stage algorithm with a set of modified cost by the concept of multi-echelon costs. The proposed method is compared with an lot-sizing method(Florian-Klein Model) to prove its effectiveness by numerical examples.

• Journal of Information Processing Systems
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• v.15 no.6
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• pp.1335-1349
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• 2019

Crowdsensing technologies can improve the efficiency of smart parking system in comparison with present sensor based smart parking system because of low install price and no restriction caused by sensor installation. A lot of sensing data is necessary to predict parking lot saturation in real-time. However in real world, it is hard to reach the required number of sensing data. In this paper, we model a saturation predication combining a time-based prediction model and a sensing data-based prediction model. The time-based model predicts saturation in aspects of parking lot location and time. The sensing data-based model predicts the degree of saturation of the parking lot with high accuracy based on the degree of saturation predicted from the first model, the saturation information in the sensing data, and the number of parking spaces in the sensing data. We perform prediction model learning with real sensing data gathered from a specific parking lot. We also evaluate the performance of the predictive model and show its efficiency and feasibility.

• Proceedings of the Korea Society for Simulation Conference
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• 1992.10a
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• pp.14-14
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• 1992

대 Lot 생산 계획은 기종변경 시간을 최소화함으로써 생산성을 높여 원가를 절감할 수 있으나 수요의 변화에 능동적으로 대처할 수 없으며 잦은 생산 Schedule 변동에 의하여 재 품절이 발생하여 Main Line이 정지되고 재공품 재고의 과다 발생으로 Lead Time이 길어지고 완제품 재고가 증가하는 등의 문제점을 내포하고 있다. JIT 시스템은 필요한 때에 물건을 필요한 양 만큼 생산제조 한다는 이상적인 생산 개념을 실현하기 위하여 평준화 생산 시스템, KANBAN시스템, 소 Lot 생산시스템 등의 하위 시스템으로 구성된 생산시스템이다. JIT 시스템은 Pull Type 시스템으로 생산의 흐름을 원활히 하고 공정을 개선하여 재공품 재고, 납기 및 생산준비 시간의 단축을 도모하여 Lot의 크기는 되도록 작게하는 소 Lot 평준화 생산 방식을 추구하기 때문에 수요의 변화에 능동적으로 대처할 수 있으며 자재 납품 업체의 부하를 평준화하여 자재 품절을 방지함으로써 생산 효율을 높일 수 있다. JIT 시스템의 이러한 효과를 계량화하여 가시적으로 보여주기 위하여 Computer simulation 기법을 도입하였다. 이 기법은 생산 Line에 물리적 변화를 가하지 않고 Model 사용자들이‘What if’라는 Scenario를 작성하여 제안된 시스템에 대한 결론을 추론하는 것이 가능하기 때문에 문제 해결에 효율적인 Tool이라 할 수 있다.

• Industrial Engineering and Management Systems
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• v.8 no.3
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• pp.131-138
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• 2009

The variable sampling inspection scheme with screening for the purpose of assuring the upper limit of maximum expected surplus loss after inspection has been proposed. In this inspection scheme, it has been assumed that a product lot consists of products manufactured through a single production line and lot quality characteristics follow a normal distribution. In the previous literature with respect to inspection schemes, it has been commonly assumed that lot quality characteristics obey a single normal distribution under the condition that all products are manufactured in the same condition. On the other hand, the production line is designed in order that the workload of respective processes becomes uniform from the viewpoint of line balancing. One of the solutions for the bottleneck process is to arrange the workshops in parallel. The lot quality characteristics from such a production line with the process consisting of some parallel workshops might not follow strictly the single normal distribution. Therefore, we expand an applicable scope of the above mentioned variable sampling inspection scheme with screening in this article. Concretely, we consider the variable sampling inspection with screening for the purpose of assuring the upper limit of average outgoing surplus quality loss in the production lots when the lot quality follows the mixed normal distribution.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.10
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• pp.756-766
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• 2011

In order to investigate the degree of apartment parking lot dust contamination, total 72 samples of parking lot dust (36 from ground parking lots and 36 from the underground parking lots) were collected in Daegu city from the end of March to the early June 2010. The dust samples were sieved below $100{\mu}m$, and analysed by ICP for 14 elements after an acid extraction. Results obtained from the source assessment of trace element using enrichment factor showed that Fe, K, Mg, Mn, Na and V were influenced by natural sources, while Cd, Cr, Cu, Ni, Pb and Zn were influenced by anthropogenic sources in both the ground parking lot and the underground parking lot. And results showed that Ca were influenced by natural sources in the ground parking lot, but influenced by anthropogenic sources in the underground parking lot. The measured values were remarkably higher in components from natural sources than in components from anthropogenic sources. Underground parking lot dust was more affected by anthropogenic sources and contaminated compared with the ground parking lot dust. Pollution index of heavy metals revealed that underground parking lot dust was 5.5 times more contaminated with heavy metal components than the ground parking lot dust. The results of correlation analysis among trace elements indicated that components in the ground parking lot were more correlated than those in the underground parking lot, and especially more correlated with natural sources-natural sources. Analysis for correlations between components and influencing factors in the underground parking lot showed that concentrations of heavy metals were higher with smaller number of parking spaces and no ventilation system, and older apartments in last paint and cleaning had relatively higher contents of heavy metals than those of recently painted and cleaned.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.3
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• pp.607-616
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• 2015

The demand for cars has been so steadily increasing based on the economic growth that the number of registered cars reached 18,870,000 as of the end of December, 2012. Due to this, the demand for the parking lots also rises continuously. Because of the limited ground space, the buildings ever becoming larger, and the trend of underground parking spaces, recent parking spaces are generally constructed underground. Accordingly, the parking lot ramps slope is limited to less than 17% by relevant laws to ensure the driver safety. However, when a driver enters a parking lot ramps whose slope is slightly steep, he frequently experiences his car body colliding with ramp brackets and often sees the scratches on ramp floor. Thus, this study is intended to prevent any damage to a structure and to contribute to ensuring the riding comfort and safety of drivers and passengers by presenting the details of proper vertical curve to prevent the collision of vehicles with ramp brackets through a vertical analysis of the first and last parts of a parking lot ramps. Because it is necessary to decide the appropriate and suitable vertical slope of a parking lot ramps, this study first identified the problems through site inspection, targeting the parking lot ramps of large buildings frequently that are used by many random people. Next, the possibility of mutual collision was assessed through a theoretical analysis of the first and last parts of a parking lot ramps. Lastly, the vertical curve of a parking ramp was analyzed to estimate its details, which was presented in this study. In conclusion, if the vertical curve presented through this study is used, it will help prevent any damage to the cars and structures, ensure the riding comfort and safety of the drivers, and further reestablish the criteria for vertical installation of a parking lot ramps.

• Korean Journal of Construction Engineering and Management
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• v.18 no.3
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• pp.52-62
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• 2017

The purpose of this study is to develope an assessment method for parking lot remodeling alternative by adopting the asset management technique. In order to identify the Level of Service(LOS) and the Evaluation Measurement(EM), literatures was implemented which documented the consideration of parking lot plan, needs of the apartments' tenant, and various design standards. In addition, the authors conducted a three-time delphi survey for the identified 5 LOS and 19 EM to evaluate suitability and necessity of them and to collect additional opinion of experts. The LOS of parking lot were categorized into 5 areas such as Environmental effect and Convenience, Accessibility and so on. The 19 EM were determined to estimate the LOS quantitatively. The researchers analyzed the degree of importance of LOS and EM by using the Analytic Hierarchy Process (AHP) method. But construction cost was excepted from the analysis, because it is used as an independent variable in alternative assessment. In conclusion, the authors proposed the estimation criteria for EM, and the method and process for alternative assessment be performed to benefit-cost analysis using the LOS variation and construction cost. The assessment method for parking lot remodeling alternative was demonstrated effective to assess the parking lot remodeling alternative by case-study. This study has a academic significance by adopting the asset management techniques in the area of the parking lot remodeling. And the assessment method is expected to help deciding a reasonable remodeling alternative of parking lot, as it ensures the diversity for remodeling of the parking lot and reflects the needs of the occupant.