• Journal of Digital Convergence
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• v.17 no.12
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• pp.191-196
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• 2019

The development of open-pit mines leads to large-area topographical changes in highland forests and can lead to severe deterioration of forests, requiring continuous monitoring. The drone photogrammetry is performed at a lower altitude than the existing manned aerial photogrammetry, and thus has a relatively high accuracy. The purpose of this study is to construct spatial information of large open pit mine using drone photogrammetry and to evaluate the accuracy and utilization of the results. The accuracy of the drone photogrammetric results was 0.018 ~ 0.063m in the horizontal direction and 0.027m ~ 0.088m in the vertical direction. These results satisfy the permissible accuracy of 1: 1,000 digital topographic map and it can be used for open mine monitoring. The geospatial information of the open pit mine can be used in various ways, and it can be used to monitor the quantitative change of a specific area for time series change through data management by periodic data acquisition. If drone photogrammetry is applied to open-pit mine monitoring in the future, work time and cost can be greatly reduced compared to the conventional GNSS or total station method, and the work efficiency can be greatly improved because more visible data can be generated.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.5
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• pp.70-75
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• 2007

A dual-frequency dual-polarization (DFDP) antenna with high isolation between two ports by embedding $2{\times}1$ mushroom-like electromagnetic bandgap (EBG) cells is proposed. The equivalent circuit of a suspended microstrip line over $2{\times}1$ EBG cells is introduced. The numerical analysis from the equivalent circuit and measured results show that the microstrip line with embedded EBG cells has a distinctive and sharp rejection band and provides near 0 dB insertion loss outside the rejection band. By embedding the EBG cells under feedlines of a conventional DFDP antenna, the isolation between two ports of the antenna is enhanced more than 20 dB, as compared to that of a conventional DFDP antenna. The proposed DFDP antenna is fabricated and measured. The simulated and measured results show a good agreement. The measured polarization purity and gain of the antenna are 25 dB and 5.77 dBi at lower band, and 35 dB and 7.13 dBi at higher band, respectively.

• Journal of Korea Port Economic Association
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• v.29 no.3
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• pp.159-174
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• 2013

This paper mainly deals with the appropriation of ship voyage allocation, using a heuristic regression model, in order to reduce total costs incurred in port, yard and at sea under the specific port condition. Because of different behavior of costs incurred in port, yard and at sea, an effort to minimize these costs by adjusting the number of voyages for three ship classes(50,000, 100,000, and 150,000-ton) should be made. For instance, if the port managers attempt to reduce the sea transport cost by increasing the annual allocated number of ship voyages classed 150,000-ton for economies of scale, they have no choice but to suffer a significant increase in queueing cost due to port congestion. To put it differently, there are trade-off relationships among the costs incurred in port, yard, and at sea. We utilized a computer simulation result to perform a couple of regression analyses in order to figure out the appropriate range of allocated number of voyages of each ship class using a heuristic approach. The detailed analytical results will be shown at the main paper. We also suggested a net present value(NPV) model to make a proper investment decision for an additional berth of 200,000-ton class that alleviates port congestion and reduces transport cost incurred both in port and at sea.

• Journal of the Korea Convergence Society
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• v.8 no.9
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• pp.301-309
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• 2017

This study analyzed the effect of cooperation activities among SMEs. In order to study empirical analysis, we classified the types of cooperation into four dimensions: technology cooperation, human resource cooperation, sales cooperation and financial cooperation. Review the role of the collaborative philosophy as a predictor. This study also analyzed the relationship between cooperation philosophy, cooperation activities and performance. The results of this study are as follows: First, the result of path analysis between cooperation philosophy and cooperation activities shows that cooperation philosophy has an important influence on technical cooperation, human resource cooperation, sales cooperation and financial cooperation. Second, the results of the relationship between cooperation activities and achievements, technical cooperation, human resource cooperation, and sales cooperation have an important influence on cooperation performance. The meaning of this study is as follows. Analyze empirical tests using the PSBP model from a partnership perspective. We are trying to verify the relationship with SMEs. Therefore, we can suggest a beneficial implication to explain the importance of cooperation activities between SMEs. Also, SME business units have a problem with technical information leakage when they form partnerships, but in order to overcome this problem, we can use cooperative philosophies and avoid negative views.

• Korean Chemical Engineering Research
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• v.56 no.1
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• pp.49-55
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• 2018

Under the era of energy crisis, hydrogen energy is considered as one of the most potential alternative energies. Liquid hydrogen has much higher energy density per unit volume than gas hydrogen and is counted as the excellent energy storage method. In this study, Navier-Stokes equations based on 2-phase model were solved by using a computational fluid dynamics program and the liquefaction process of gaseous hydrogen passing through a cryogenic cooling tube was analyzed. The copper with high thermal conductivity was assumed as the material for cryogenic cooling tube. For different inlet velocities of 5 m/s, 10 m/s and 20 m/s for hydrogen gas, the distributions of fluid temperature, axial and radial velocities, and volume fractions of gas and liquid hydrogens were compared. These research results are expected to be used as basic data for the future design and fabrication of cryogenic cooling tube to transform the hydrogen gas into liquid hydrogen.

• 대한공업교육학회지
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• v.44 no.2
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• pp.123-141
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• 2019

The purpose of this study is to provide basic data that can be used for the development of technology textbooks of Nigeria-Korea Model School by analyzing external and internal aspects of Illustration in Nigerian primary school technology textbooks, and 10 textbooks used in Nigeria were analyzed. Based on the results of the study, the conclusions are as follows. First, the form of the visual data should be diversified into a picture, a cartoon, a diagram, and a diagram from the photograph center, and provide various information closely related to the contents of the technology. Second, it is necessary to increase the size of illustration so as to induce learners to be motivated, and to enhance the effect of editing. Third, currently, partial enlargement data is rarely used, but visual material should be partially enlarged in order to express a detail part of product. Fourth, diversity of editing should be done by using circular or background omission rather than using only rectangle uniformly in visual material. Fifth, in terms of gender equality, it is necessary to deviate from male-centric visual materials and edit them with consideration for women. Sixth, in order to provide learner-centered textbooks, the role of visual materials should be extended to 'inducement of motivation', 'activity guidance', and 'activity result' in addition to 'providing data'. Finally, in terms of the function of visuals, the quality of textbooks should be upgraded by utilizing auxiliary and decorative functions in addition to essential functions.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.12
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• pp.2714-2726
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• 1997

In this paper, adaptive symbol changes-based medical image compression method is presented. First, the differenctial image domain is obtained using the differentiation rules or obaptive predictors applied to original mdeical image. Also, the algorithm determines the context associated with the differential image from the domain. Then prediction symbols which are thought tobe the most probable differential image values are maintained at a high value through the adaptive symbol changes procedure based on estimates of the symbols with polarity coincidence between the differential image values to be coded under to context and differential image values in the model template. At the coding step, the differential image values are encoded as "predicted" or "non-predicted" by the binary adaptive arithmetic encoder, where a binary decision tree is employed. The simlation results indicate that the prediction hit ratios of differential image values using the proposed algorithm improve the coding gain by 25% and 23% than arithmetic coder with ISO JPEG lossless predictor and arithmetic coder with differentiation rules or adaptive predictors, respectively. It can be used in compression part of medical PACS because the proposed method allows the encoder be directly applied to the full bit-planes medical image without a decomposition of the full bit-plane into a series of binary bit-planes as well as lower complexity of encoder through using an additions when sub-dividing recursively unit intervals.

• The KIPS Transactions:PartD
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• v.8D no.6
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• pp.705-714
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• 2001

The computing systems of today expanded business trade and distributed business process Internet. More and more systems are developed from components with exactly reusability, independency, and portability. Component based development is focused on advanced concepts rater than passive manipulation or source code in class library. The primary component construction in CBD. However, lead to an additional cost for reconstructing the new component with CBD model. It also difficult to serve component information with rapidly and exactly, which normalization model are not established, frequency user logging in Web caused overload. A lot of difficult issues and aspects of Component Based Development have to be investigated to develop good component-based products. There is no established normalization model which will guarantee a proper treatment of components. This paper elaborates on some of those aspects of web application to adapt user requirement with exactly and rapidly. Distributed components in this paper are used in the most tiny size on network and suggest the network-addressable interface based on business domain. We also discuss the internal and external specifications for grasping component internal and external relations of user requirements to be analyzed. The specifications are stored on Servlets after dividing the information between session and entity as an EJB (Enterprise JavaBeans) that are reusable unit size in business domain. The reusable units are used in business component through query to get business component. As a major contribution, we propose a systems model for registration, auto-arrange, search, test, and download component, which covers component reusability and component customization.

• The KIPS Transactions:PartC
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• v.13C no.7 s.110
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• pp.803-812
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• 2006

This paper analytically evaluates the FEC(Forward Error Correction) symbol size's effect on the performance and energy consumption of 802.11 protocol with the block FEC algorithm over WSN(Wireless Sensor Network). Since the basic recovery unit of block FEC algorithms is symbols not bits, the FEC symbol size affects the packet correction rate even with the same amount of FEC check bits over a given WSN channel. Precisely, when the same amount of FEC check bits are allocated, the small-size symbols are effective over channels with frequent short bursts of propagation errors while the large ones are good at remedying the long rare bursts. To estimate the effect of the FEC symbol site, the paper at first models the WSN channel with Gilbert model based on real packet traces collected over TIP50CM sensor nodes and measures the energy consumed for encoding and decoding the RS (Reed-Solomon) code with various symbol sizes. Based on the WSN channel model and each RS code's energy expenditure, it analytically calculates the transmission efficiency and power consumption of 802.11 equipped with RS code. The computational analysis combined with real experimental data shows that the RS symbol size makes a difference of up to 4.2% in the transmission efficiency and 35% in energy consumption even with the same amount of FEC check bits.

• Archives of design research
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• v.17 no.3
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• pp.27-38
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• 2004

It is important for designers to be supported with their decision-making on colours which is often based on personal distinction rather than logical dialogue that may lead to confusion within communicating with others. To help these problems and to gain productivity, we would like to propose a way to define colour grouping method. In other words, the purpose of this study is to help to improve the communication and productivity within the design and designers. The grouping was based and inspired by from the studies of Kobayashi, Hideaki Chijiawa, Allis Westgate and Martha Gill. The study of grouping is based on the "tones" of each group, as they seem to reflect a designer s sentimentalism of chosen colours the best. Each of these groups will be named Bright , Pastel ,Deep and Neutral The general concept of each groups are: - Bright: high quality of pixels of primary colour - Pastel: primary colour with white - - Deep: Primary colour with gray or black - Neutral: colours that does not include any of above Each of the colour group has been allocated into Si-Hwa Jung's colour charts and colour prism to visualize the relationships between the colour groups. These four groups and the colours included in them will be broken down to smaller groups in order to make colour palette. This would break the barrier and result in using colours in groups as well as crossover coordination. This study would result in new ways of using colurs for designers designers