• Journal of the Korea Society for Simulation
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• v.19 no.2
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• pp.127-135
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• 2010

The validation of a simulation model is a key to demonstrate that the simulation model is reliable. However, among various validation methods have been introduced, it is very poor to research the specific techniques for the time series data. Therefore, this paper suggests the methodology to verify the simulation using the time series data by Wavelet Transform, Power Spectrum and Coherence. This method performs 2 steps as followed. Firstly, we get spectrum using the Wavelet transform available for non-periodic signal separation. Secondly, we compare 2 patterns of output data from simulation model and actual system by Coherence Analysis. As a result of comparing it with other validation techniques, the suggested way can judge simulation model accuracy more clearly. By this way, we can make it possible to perform the simulation validation test under various situations using detailed sectional validation method, which has been impossible using a single statistics for the whole model.

• Journal of Navigation and Port Research
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• v.41 no.3
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• pp.109-118
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• 2017

The key word (KW) is a set of words to clearly express the important causations of marine accidents; they are determined by a judge in a Korean maritime safety tribunal. The selection of KW currently has two main issues: one is maintaining consistency due to the different subjective opinion of each judge, and the second is the large number of KW currently in use. To overcome the issues, the systematic framework used to construct KW's needs to be optimized with a minimal number of KW's being derived from a set of Common Words (CW). The purpose of this study is to identify a set of CW to develop the systematic KW construction frame. To fulfill the purpose, the word reduction method to find minimum number of CW is proposed using P areto distribution function and Pareto index. A total of 2,642 KW were compiled and 56 baseline CW were identified in the data sets. These CW, along with their frequency of use across all KW, are reported. Through the word reduction experiments, an average reduction rate of 58.5% was obtained. The estimated CW according to the reduction rates was verified using the Pareto chart. Through this analysis, the development of a systematic KW construction frame is expected to be possible.

• Science of Emotion and Sensibility
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• v.22 no.2
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• pp.37-48
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• 2019

Current research explores the effect of language on the perception of facial emotion as suggested by the psychological construction theory of emotion by using a psychophysical method. In this study, we hypothesize that the perception of facial expression may be influenced if the observer is shown an affective word before he/she judges an expression. Moreover, we suggest that his/her understanding of a facial emotion will be in line with the conceptual context that the word denotes. During the two experiments conducted for this project, a control stimulus or words representing either angry or happy emotions were briefly presented to participants before they were shown a target face. These target faces were randomly selected from seven faces that were gradually morphed to show neutral to angry (in Experiment 1) and neutral to happy (in Experiment 2) expressions. The participants were asked to perform a two-alternative forced choice (2AFC) task to judge the emotion of the target face (i.e., decide whether it is angry or neutral, or happy or neutral). The results of Experiment 1 (when compared with the control condition) showed that words denoting anger decreased the point of subjective equality (PSE) for judging the emotion of the target as anger, whereas words denoting happiness increased the PSE. Experiment 2, in which participants had to judge expressions on a scale from happy to neutral, produced a contrasting pattern of results. The outcomes of this study support the claim of the psychological construction theory of emotion that the perception of facial emotion is an active construction process that may be influenced by information (such as affective words) that provide conceptual context.

• Journal of the Korea Society of Computer and Information
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• v.29 no.1
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• pp.273-285
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• 2024

With the active utilization of Online Judge (OJ) systems in the field of education, various studies utilizing learner data have emerged. This research proposes a problem recommendation based on a user-based collaborative filtering approach with learner data to support learners in their problem selection. Assistance in learners' problem selection within the OJ system is crucial for enhancing the effectiveness of education as it impacts the learning path. To achieve this, this system identifies learners with similar problem-solving tendencies and utilizes their problem-solving history. The proposed technique has been implemented on an OJ site in the fields of algorithms and programming, operated by the Chungbuk Education Research and Information Institute. The technique's service utility and usability were assessed through expert reviews using the Delphi technique. Additionally, it was piloted with site users, and an analysis of the ratio of correctness revealed approximately a 16% higher submission rate for recommended problems compared to the overall submissions. A survey targeting users who used the recommended problems yielded a 78% response rate, with the majority indicating that the feature was helpful. However, low selection rates of recommended problems and low response rates within the subset of users who used recommended problems highlight the need for future research focusing on improving accessibility, enhancing user feedback collection, and diversifying learner data analysis.

• Journal of Wetlands Research
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• v.26 no.3
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• pp.279-284
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• 2024

Recently, the frequency and intensity of torential rains caused by climate change are increasing, and the damage to reservoir collapse in local governments continues to occur. Most local government reservoirs are aged reservoirs that have been built for more than 50 years, and there is a high risk of collapse due to recent heavy rainfall. In order to prevent reservoir collapse or overflow caused by heavy rainfall, a decision-making support system that can judge risks due to changes in storage capacity is needed. In this study, a reservoir discharge simulation model was constructed using a system dynamics technique that can dynamically represent causal relationships between various variables. Through discharge simulation, the change in storage capacity due to rainfall was analyzed, and the operation time and termination time of the discharge facility to prevent overflow of the reservoir were analyzed. Using the results of this study, it is possible to determine the timing of the overflow of the reservoir due to torrential rain, and also the capacity and operation timing of the discharge facility to prevent overflow can be known. hrough this, it is expected that local governments will be able to judge the risk of damage to reservoirs and establish a preliminary response plan to prevent damage.

• Journal of the Korean School Mathematics Society
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• v.4 no.2
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• pp.115-123
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• 2001

In its seventh revision to start in 2001, mathematics will have a new emphasis in the middle school curriculum. Mathematics subject is now composed of practical things in the use of mathematics. Also, the future of new generation, which has been known as the information age, places much focus on problem-solving in order to collect, analyze, synthesize, and judge various kinds informations. This demand of problem-solving ability is not only related with mathematical education but, along the entire educational process, its related to actual life. With this change of social structure, the importance of school education is increasing rapidly. Therefore, in order to grow abilities and create new knowledge, adapted this new method of self-oriented learning in groups to middle school 2nd graders for one year, the results were as follows : 1. Students developed their ability of the use of mathematical terms and signs correctly. 2. Students' mathematical knowledge and problem-solving ability improved as they had increased interest in mathematics. 3. Students' peership was enhanced through their communication and cooperative activities in groups during the class. 4. Students themselves were more willing to volunteer and participate during the class.

• Journal of the Korean Society of Safety
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• v.27 no.2
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• pp.34-41
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• 2012

In this study, it has been proposed the new type of temporary bridge which is structural performance maximization to integrated cover plate and girder as well as roll of lining board. Of all temporary bridge integrated cover plate and main girder in the form of a new type of structure is advantageous for the judge, but to the field of transport difficulties and challenges due to high altitude operations to take advantage of this challenge and deliver a structured, easy transport, and the synthesis of lining board possible was proposed. Lining board proposed in this study through experimental synthesis and analysis of the factors that influence the effectiveness of the construction and economic development in the construction method was superior, compared to the conventional lining board.

• Journal of Arbitration Studies
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• v.27 no.2
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• pp.107-119
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• 2017

In the process of online trading, many unexpected conflicts may occur. The consumer wishes to perform transactions with a seller by trusting the seller's listings, but there are times when even major companies such as Kakao edit their original listings. When the seller edits their listing, it is extremely difficult for the consumer to prove and deal with the problem. If they don't deal with them carefully they may be accused of denigration. This study proposes a consumer protection system to resolve this problem. In case a problem occurs, proof that the original listing was edited can be submitted to a judge in court by using this system, thus preventing these types of problems from happening. If this system is installed, both the seller and consumer know that the terms of contract cannot be falsely changed to the advantage of either side, so the source of the problem can be prevented. This study analyzes the reasons behind the conflicts and presents a systematic way of preventing the problem. This method does not present a financial burden, and provides a way for transactions to be held based on trust for the seller and consumer.

• Journal of the Korea Society of Computer and Information
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• v.22 no.2
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• pp.1-7
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• 2017

Recently, NAND flash memory, which is used as a storage medium, is replacing HDD (Hard Disk Drive) at a high speed due to various advantages such as fast access speed, low power, and easy portability. In order to apply NAND flash memory to a computer system, a Flash Translation Layer (FTL) is indispensably required. FTL provides a number of features such as address mapping, garbage collection, wear leveling, and hot data identification. In particular, hot data identification is an algorithm that identifies specific pages where data updates frequently occur. Hot data identification helps to improve overall performance by identifying and managing hot data separately. MHF (Multi hash framework) technique, known as hot data identification technique, records the number of write operations in memory. The recorded value is evaluated and judged as hot data. However, the method of counting the number of times in a write request is not enough to judge a page as a hot data page. In this paper, we propose hot data identification which considers not only the number of write requests but also the persistence of write requests.

• Journal of Information Technology Services
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• v.17 no.1
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• pp.135-153
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• 2018

E-Card Service for Child Nutrition Program is one of the main public policy services nowadays. In case of inconvenience during the use of the e-cards, it is recommended to cooperate with related organizations in order to promptly handle and provide guidance, and thoroughly manage child feeding service such as hygiene, nutrition and kindness etc. To do so, it is very important to provide food service that meets local actual conditions and children's needs in a cost effective manner for the underage who are worried about the poorly-fed by understanding the pattern of child feeding e-card service. Hence. this paper aims to investigate how child feeding e-card service efficiently provides meals according to the local situation and children's needs through big data analysis and to propose a method of identifying welfare conditions according to the purpose of service with actual application examples. The results suggest that, first of all, this study is able to judge appropriateness of public institution's policy in a timely and repetitive manner through non-standard data analysis such as Naver News and transaction data. Secondly, this paper proposes a multi-layered analysis framework, which performs online open data analysis to detect policy issues, visualizes retrieval and preprocessing of real data, and performs abnormal pattern recognition. These will be worthy of reference to other similar projects.