• Journal of Korea Water Resources Association
• /
• v.43 no.11
• /
• pp.995-1009
• /
• 2010

Accelerated soil erosion due to extreme climate change, such as increased rainfall intensity, and human-induced environmental changes, is a widely recognized problem. Existing soil erosion models are generally based on the gross erosion concept to compute annual upland soil loss in tons per acre per year. However, such models are not suitable for event-based simulations of erosion and deposition in time and space. Recent advances in computer geographic information system (GIS) technologies have allowed hydrologists to develop physically based models, and the trend in erosion prediction is towards process-based models, instead of conceptually lumped models. This study aims to propose an effective and robust distributed rainfall-sediment yield-runoff model consisting of basic element modules: a rainfall-runoff module based on the kinematic wave method for subsurface and surface flow, and a runoff-sediment yield-runoff model based on the unit stream power method. The model was tested on the Cheoncheon catchment, upstream of the Yongdam dam using hydrological data for three extreme flood events due to typhoons. The model provided acceptable simulation results with respect to both discharge and sediment discharge even though the simulated sedigraphs were underestimated, compared to observations. The spatial distribution of erosion and deposition demonstrated that eroded sediment loads were deposited in the cells along the channel network, which have a short overland flow length and a gentle local slope while the erosion rate increased as rainfall became larger. Additionally, spatially heterogeneous rainfall intensity, dependant on Thiessen polygons, led to spatially-distinct erosion and deposition patterns.

• Journal of The Korean Association For Science Education
• /
• v.33 no.7
• /
• pp.1471-1485
• /
• 2013

The purpose of this study was to develop a HAM (Heuristic Attention Model) by analyzing the difference between eye movements according to the science achievement of elementary school students on discrimination task. Science achievement was graded by the results of the Korea national achievement test conducted in 2012 for a random sampling of classes. As an assessment tool to check discrimination task, two discrimination measure problems from TSPS (Test of Science Process Skill, developed in 1994) which were suitable for an eye tracking system were adopted. The subjects of this study were 20 students from the sixth grade who agreed to participate in the research. SMI was used to collect EMD (eye movement data). Experiment 3.2 and BeGaze 3.2 programs were used to plan experiments and analyze EMD. As a result, eye movements of participants in discrimination tasks varied greatly in counts and duration of fixation, first fixation duration, and dwell time, according to students' science achievement and difficulty of the problems. By the analysis of EMD, strategies of the students' problem-solving could be found. During problem solving, subjects' eye movements were affected by visual attention; bottom-up attention, top-down attention and convert attention, and aflunter attention. In conclusion, HAM was developed, and it is believed to help in the development of a science learning program for underachievers.

• The Korean Journal of Archival Studies
• /
• no.63
• /
• pp.145-165
• /
• 2020

, in collaboration with Mary Kelly, Kay Hunt and Margaret Harrison, tells the story of workers in the 1970s. Since the late 1960s, the world has undergone many political and social changes, and social movements have been active to protect the socially underprivileged, including women, children and workers. This phenomenon led to the diversification of the collection of the general public, the community, and the minority, and the expansion of the artist's political remarks and themes in the art world. , completed in conjunction with these social issues, surveyed and recorded the reality of workers in a factory in London and produced it as a artwork. is a collaborative work of three artists, a record of workers in the 1970s, and a record of the labor situation, factory, and even the history of the region. Therefore, this study examined the methods and features of , which dealt with the lives of women workers in the 1970s, based on social conditions.

• Journal of the Society of Naval Architects of Korea
• /
• v.29 no.1
• /
• pp.173-190
• /
• 1992

Considerable number of offshore platforms have been built in Korean shipyards ever since 1976. Unlike for the cases of building ships, however, negligible efforts have been made to establish planning methodology for building onshore platforms. Severe congestion has been shown in the processes of assemblying modules of platforms. The module which is the upper part of a platform is a steel structure accommodating various types of outfittings and machinaries. The production planned without proper consideration on allocating work loads by trade used to show severe interferences among trades of workers and resulted in delayed completion. In this paper, a method of planning module assembly in consideration of leveling work loads by trade is discussed. A system of planning has been formulated and tested on a exampled case of producing a mix of 72 modules. The test showed a possibility of saving 31% of manpower and trimming 11% of through put time.

• Management & Information Systems Review
• /
• v.33 no.1
• /
• pp.45-63
• /
• 2014

A trading system is a computer trading program that automatically submits trades to an exchange. Mechanical a trading system to execute trade is spreading in the stock market. However, a trading system to trade a single asset might occur instability of the profit because payoff of this system is determined a asset movement. Therefore, it is necessary to develop a trading system that is trade two assets such as a pair trading that is to sell overvalued assets and buy the undervalued ones. The aim of this study is to propose a relative value based trading system designed to yield stable and profitable profits regardless of market conditions. In fact, we propose a procedure for building a trading system that is based on the rough set analysis of indicators derived from a price ratio between two assets. KOSPI 200 index futures and S&P 500 index futures are used as a data for evaluation of the proposed trading system. We intend to examine the usefulness of this model through an empirical study.

• The Journal of the Acoustical Society of Korea
• /
• v.39 no.5
• /
• pp.414-423
• /
• 2020

In this paper, we propose a Dilated Convolution Gate Linear Unit (DCGLU) to mitigate the lack of sparsity and small receptive field problems caused by the segmentation map extraction process in sound event detection with weak labels. In the advent of deep learning framework, segmentation map extraction approaches have shown improved performance in noisy environments. However, these methods are forced to maintain the size of the feature map to extract the segmentation map as the model would be constructed without a pooling operation. As a result, the performance of these methods is deteriorated with a lack of sparsity and a small receptive field. To mitigate these problems, we utilize GLU to control the flow of information and Dilated Convolutional Neural Networks (DCNNs) to increase the receptive field without additional learning parameters. For the performance evaluation, we employ a URBAN-SED and self-organized bird sound dataset. The relevant experiments show that our proposed DCGLU model outperforms over other baselines. In particular, our method is shown to exhibit robustness against nature sound noises with three Signal to Noise Ratio (SNR) levels (20 dB, 10 dB and 0 dB).

• Journal of Digital Convergence
• /
• v.10 no.11
• /
• pp.427-432
• /
• 2012

The article herein suggested a compound repository and a descriptive method to develop a compound knowledge process. A data target saved in a compound knowledge repository suggested in this article includes all compound knowledge meta data and digital resources, which can be divided into the three following factors according to the purpose: user roles, functional elements, and service ranges. The three factors are basic components to describe abstract models of repository. In this article, meta data of compound knowledge are defined by being classified into the two factors. A component stands for the property about a main agent, activity unit or resource that use and create knowledge, and a context presents the context in which knowledge object are included. An agent of the compound knowledge process performs classification, registration, and pattern information management of composite knowledge, and serves as data flow and processing between compound knowledge repository and user. The agent of the compound knowledge process consists of the following functions: warning to inform data search and extraction, data collection and output for data exchange in an distributed environment, storage and registration for data, request and transmission to call for physical material wanted after search of meta data. In this article, the construction of a compound knowledge repository for recommendation system to be developed can serve a role to enhance learning productivity through real-time visualization of timely knowledge by presenting well-put various contents to users in the field of industry to occur work and learning at the same time.

• Journal of Digital Convergence
• /
• v.10 no.11
• /
• pp.619-626
• /
• 2012

The purpose of this study is to compare and analyze the utilization state of smart devices and the recognition level of educational application development of the general high school and the specialized high school. Specialized high school students preferred the utilization of smart devices more and daily spent on the devices more time than general high school students. As for the learning field, language for the general high school and the certificate of qualification for the specialized high school were shown high. The merit of smart device utilization is the use of spare time and its infrastructure was most required. The most expected content is a video lecture for the general high school and cooperative learning for the specialized high school and the most satisfied point was mobility. The specialized high school students feel more necessity about the application development for culinary education and had a plan to utilize it more and more preferred practice videos. As for the food development areas, the general high school students hoped simple food and the specialized high school students did cooking technician food and they both hoped the application to be uploaded in portal sites and the department homepage. The application development for culinary education is required to focus simulation learning including practice videos and cooking recipes and add an evaluation function to check the academic achievement levels. It is required to provide the subject goals of each course and concrete information on solving problems. Contents including video, music, texts need to be attached to improve learning immersion. There should be the beginning and development of a lesson and the flow of arrangement and communication between main bodies of learning should be improved by utilization of SNS cooperative learning services.

• The Journal of the Korea Contents Association
• /
• v.14 no.9
• /
• pp.529-537
• /
• 2014

To establish a foundation to objectively interpret Chosun history, we construct people network of the Chosun dynasty. The network shows scale free network properties as if most social networks do. The people network is composed of 1,379 nodes and 3,874 links and its diameter is 14. To analysis of the network dynamics, whole network that is composed of 27 king networks were constructed by adding the first king, Taejo network to the second king, Jeongjong network and then continuously adding the next king networks. Interestingly, betweenness and closeness centralities were gradually decreased but stress centrality was drastically increased. These results indicate that information flow is gradually slowing and hub node position is more centrally oriented as growing the network. To elucidate key persons from the network, k-core and MCODE algorithms that can extract core or module structures from whole network were employed. It is a possible to obtain new insight and hidden information by analyzing network dynamics. Due to lack of the dynamic interacting data, there is a limit for network dynamic research. In spite of using concise data, this research provides us a possibility that annals of the Chosun dynasty are very useful historical data for analyzing network dynamics.

• Journal of Convergence for Information Technology
• /
• v.10 no.2
• /
• pp.39-48
• /
• 2020

Many studies have been conducted to analyze factors that affect customer satisfaction, and service quality improvement in the parcel delivery industry. Most of these studies have a limited number of respondents using methods such as surveys and interviews. Therefore, this study aims to supplement the shortcomings of previous studies, by searching and analyzing the common major topics related to the complaints pointed out by consumers and suppliers in the parcel delivery service with cases of consumer counseling, and articles that reflect the complaints of workers in the industry. In addition, by analyzing the trend of these topics, we attempted to discover new topics and suggest implications. In conclusion, topics such as delay/lost/wrong deliveries as well as the fierce competition in the parcel delivery industry, turned out to be central aspects. As a result of the topic trend analysis, talks with international couriers have recently increased, and many conflicts related to apartment parcel delivery have been dealt with. The topics presented in this study are mainly focused on the contents of previous studies, but we expect that new and valuable topics can be derived by adding other data and analysis methods, such as internal counseling and academic literature.