• Proceedings of the Korean Information Science Society Conference
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• 2001.10b
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• pp.1-3
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• 2001

컨테이너 터미널에서의 선석 및 크레인 일정계획은 일정 기간 동안 입항 예정인 선박들을 대상으로 접안 위치와 접안 시기 및 기간을 결정하며, 또한 각 선박별로 컨테이너를 싣고 내릴 크레인을 배정하되 각 크레인의 서비스 시작과 완료시간가지 지정하는 전 과정을 포함한다. 이 문제는 여러 선박들 사이의 시간적 공간적 제약관계를 준수하고 크레인들을 충돌 없이 각 선박에 할당하여야 하는 제약조건 만족 문제인 동시에, 각 선박의 선호 위치와 희망 입출항 시간을 최대한 준수해야 하는 최적화 문제이기도 하다. 기존의 연구에서는 제약만족탐색기법을 사용하여 초기계획을 수립한 후 최적의 해를 유도해 내기 위해 휴리스틱 교정기법을 제약만족 탐색기법의 틀 내에서 반복적으로 적용하였다. 본 논문에서는 반복적 개선 탐색 도중에 도출되는 해의 정보를 이용하여 새로운 제약조건을 추가함으로써 다음 제약만족 탐색 시 보다 쉽게 더 충은 해를 찾을 수 있도록 하였으며 이 방법을 기존의 휴리스틱 교정기법과 결합하여 휴리스틱 교정기법의 성능을 향상시켰다.

• Journal of The Korean Society of Grassland and Forage Science
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• v.40 no.1
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• pp.66-72
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• 2020

This study aimed to discuss the optimal seeding and harvesting dates with growing degree days(GDD) via meta-data of whole crop maize(WCM). The raw data (n=3,152) contains cultivation year, cultivars, location, seeding and harvesting dates collected from various reports such as thesis, science journals and research reports (1982-2012). The processing was: recording, screening and modification of errors; Then, the final dataset (n=121) consists of seeding cases (n=29), and harvesting cases (n=92) which were used to detect the optimum. In addition, the optimal periods considering tolerance range and GDD also were estimated. As a result, the optimum seeding and harvesting periods were 14th April ~ 3rd May and 15th August ~ 4th September, respectively; where, their GDDs were 23.7~99.6℃ and 1,328.7~1,602.1℃, respectively. These GDDs could be used as a judge standard for selecting the seeding and harvesting dates.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.2
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• pp.325-332
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• 2016

Configuring excavator attachments and engine sizes is the prerequisite for appropriate excavator assignment. Existing experience based configuration practice is lack of scientific rational because many variables (e.g., equipment motion data, soil and rock type and condition, equipment's engineering dimension along with bucket properties, job and management conditions etc.) should be considered simultaneously and timely fashion. This paper presents a new excavator configuration searching method that identifies the most favorable excavator configuration (i.e., the optimal set of excavator's maximum digging height and bucket size) to complement these existing practices. The method coded by using MATLAB identifies an optimal excavator configuration by considering those variables causing the variability of productivity. A case study is presented to demonstrate and to verify the system.

• Journal of Intelligence and Information Systems
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• v.6 no.2
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• pp.1-14
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• 2000

The berth and crane scheduling problem in a container terminal encompasses the whole process of assigning berth to each ship, determining the duration of berthing, assigning container cranes to each ship, and determining the specific start and end time of each crane service, for all the ships scheduled to be arriving at the terminal during a certain scheduling horizon. This problem is basically a constraint satisfaction problem in which cranes and berths should be assigned in such a way that all the spatial and temporal constraints are satisfied without any interference. However, it is also an optimization problem because the requested arrival and departure time should be met for as many of the scheduled ships as possible, while the operation cost of the terminal should be minimized. In this paper, we present an effective and efficient approach to solving this type of problem, which combines constrain satisfaction search and heuristic repair. We first employ a constraint satisfaction search to find a feasib1e solution. Then, the feasible solution is modified to a more optimal one by iteratively applying our heuristic repair operations within the framework of constraint satisfaction search. Experimental results with a real data from Pusan East Container Terminal showed that our approach can derive a schedule of satisfactory quality in a very short time.

• Korean Journal of Construction Engineering and Management
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• v.11 no.6
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• pp.54-64
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• 2010

A firm decides to go to the project based on its investment analysis. However, the cash flows generated from the real project can not be always coincident with what expected as it follows uncertain behavior and the asymmetric payoff caused by the managerial flexibilities involved in the real asset affects the project value. Amongst various managerial flexibilities entailed in most of the real assets, although investment delay has been known to enhance the project value thanks to its ability to provide new market information to management, the related research to select the time to invest have been just few. Therefore, this research aims to show the theoretical framework to decide when to invest reflecting the behaviors of increasing project value and loss recovery cost due to investment delay with option pricing, related financial economic, and variational theories.

• Journal of the Korea Society of Computer and Information
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• v.9 no.4 s.32
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• pp.117-125
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• 2004

The berth and crane scheduling problem in a container terminal encompasses the whole process of assigning berth to each ship. determining the duration of berthing, assigning container cranes to each ship, and determining the specific start and end time of each crane service, for all the ships scheduled to be arriving at the terminal during a certain scheduling horizon. This problem is basically a constraint satisfaction problem in which all the constraints should be satisfied. However, it is also an optimization problem because the requested arrival and departure time should be met for as many of the scheduled ships as possible. while the operation cost of the terminal should be minimized. In this paper. I present an effective approach to solving this problem, which combines both constraint satisfaction search and iterative improvement search. I test this method on a real world container terminal problem and the results show that the method can produce better results than any other existing method.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.41-50
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• 2020

The purpose of this study was to identify latent classes in school readiness which were measured by both parents and teachers, and to test the relationship with school adaption, academic abilities, problematic behaviors, self-esteem, and happiness. Latent Profile Analysis (LPA), MANOVA, and one-way ANOVA were conducted using the data of 1,154 1st to 3rd grade elementary school students, and the data was collected between the 7th year (2014) to the 10th year (2017) from the Korean Children and Youth Panel Study. The results of study were as follows. First, four school readiness groups were identified: the consistent low group, parent perceived high group, the teacher perceived high group, the consistent high group. Second, the consistent high group and the teacher perceived high group showed relatively better academic abilities and school adaption than the consistent low group. Furthermore, the consistent high group showed higher academic abilities, self-esteem, and happiness, but lower problematic behaviors than the consistent low group. The findings of this study could be utilized as preliminary data for understanding school readiness to promote successful school adaption and psychological well-being of children.

• Journal of the Korea Society of Computer and Information
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• v.28 no.7
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• pp.57-65
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• 2023

Various studies to enhance the accuracy of rice production forecasting are focused on improving the accuracy of the models. In contrast, there is a relative lack of research regarding the data itself, which the prediction models are applied to. When applying the same dependent variable and prediction model to two different sets of rice production data composed of distinct features, discrepancies in results can occur. It is challenging to determine which dataset yields superior results under such circumstances. To address this issue, by identifying potential influential features within the data before applying the prediction model and centering the modeling around these, it is possible to achieve stable prediction results regardless of the composition of the data. In this study, we propose a method to adjust the composition of the data's features in order to select optimal base variables, aiding in achieving stable and consistent predictions for rice production. This method makes use of the Korea Meteorological Administration's ASOS data. The findings of this study are expected to make a substantial contribution towards enhancing the utility of performance evaluations in future research endeavors.

• Journal of Digital Contents Society
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• v.15 no.5
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• pp.569-577
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• 2014

The various services are required to user in time and space. It is important to provide suitable service to user according to user's circumstance. Therefore it is need to provide services to user through mining by latest information of user activity and service history. In this paper we propose a mining method to search association rule using service history based on spatiotemporal information and service ontology. In this method, we find the associative service pattern using level-cross tree on service ontology. The proposed method is to be a basic research to find the service pattern to provide high quality service to user according to season, location and age under the same context.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.6
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• pp.38-47
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• 2019

The purpose of this study was to identify latent classes in executive function difficulty of first graders depends on evaluations from their mother and teacher and to investigate how its related with their school adaption and academic performance in second grade. Based on the model of the latent profile analysis, the 8th and 9th wave data from Korean Children and Youth Panel Survey were analyzed. The results of this study were as following. First, results showed that there were three types of latent classes in the executive function difficulty depend on evaluations from their mother and teacher: 'low executive function,' 'students who were highly evaluated by mother,' and 'students who were highly evaluated by teacher.' Second, students' executive function difficulty had a direct effect on the students' school adaption and academic performance in their second year of school. Especially students who were evaluated as having the lowest executive function difficulty showed significant higher means than students who were evaluated higher by mother and teacher. This study emphasized the importance of multiple evaluation in students' executive function difficulty to provide an educational intervention.