• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.16-22
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• 2020

The Korea Institute of Ocean Science & Technology is developing a free-fall cone penetration test system (FFCPT) that can acquire the characteristics of the seabed surface soil. To obtain the data through the FFCPT, a method of storing the signals for the entire time or a method of storing the signal for user-defined time can be considered. For efficient data storage and management, it is advantageous that data be stored by user definition. Therefore, this study analyzed the basic behavior using the signal acquired through a sensor mounted in the FFCPT and developed a trigger method to recognize the start and end of data storage using a depth sensor. The start and endpoints of the fall were determined using the moving average difference of 3 and 0.03 seconds of the depth signal. A real sea-trial test was performed using the FFCPT, and the developed trigger was operated normally.

• Journal of the Korean Society for information Management
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• v.21 no.3
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• pp.1-14
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• 2004

Visualization of documents will help users when they do search similar documents. and all research in information retrieval addresses itself to the problem of a user with an information need facing a data source containing an acceptable solution to that need. In various contexts. adequate solutions to this problem have included alphabetized cubbyholes housing papyrus rolls. microfilm registers. card catalogs and inverted files coded onto discs. Many information retrieval systems rely on the use of a document surrogate. Though they might be surprise to discover it. nearly every information seeker uses an array of document surrogates. Summaries. tables of contents. abstracts. reviews, and MARC recordsthese are all document surrogates. That is, they stand infor a document allowing a user to make some decision regarding it. whether to retrieve a book from the stacks, whether to read an entire article, etc. In this paper another type of document surrogate is investigated using a grouping method of term list. lising Multidimensional Scaling Method (MDS) those surrogates are visualized on two-dimensional graph. The distances between dots on the two-dimensional graph can be represented as the similarity of the documents. More close the distance. more similar the documents.

• The Journal of Korean Academy of Prosthodontics
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• v.31 no.3
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• pp.423-446
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• 1993

Titanium and its alloys are finding increasing use in medical devices and dental implants. The strong selling point of titanium is its resistance to the highly corrosive body fluids in which an implant must survive. This corrosion resistance is due to a tenacious passive oxide or film which exists on the metal's surface and renders it passive. Potentiodynamic polarization measurement is one of the most commonly used electro-chemical methods that have been applied to measure corrosion rates. And the potentiodynamic polarization test supplies detailed information such as open circuit, rupture, and passivation potential. Furthermore, it indicates the passive range and sensitivity to pitting corrosion. This study was designed to compare the corrosion resistance of the commonly used dental implant materials such as CP Ti, Ti-6A1-4V, Co-Cr-Mo alloy, and 316L stainless steel. And the effects of galvanic couples between titanium and the dental alloys were assessed for their useful-ness-as. materials for superstructure. The working electrode is the specimen , the reference electrode is a saturated calomel electrode (SCE), and the counter electrode is made of carbon. In $N_2-saturated$ 0.9% NaCl solutions, the potential scanning was performed starting from -800mV (SCE) and the scan rate was 1 mV/sec. At least three different polarization measurements were carried out for each material on separate specimen. The galvanic corrosion measurements were conducted in the zero-shunt ammeter with an implant supraconstruction surface ratio of 1:1. The contact current density was recorded over a 24-hour period. The results were as follows : 1. In potential-time curve, all specimens became increasingly more noble after immersion in the test solution and reached between -70mV and 50mV (SCE) respectively after 12 hours. 2. The Ti and Ti alloy in the saline solution were most resistant to corrosion. They showed the typical passive behavior which was exhibited over the entire experimental range. Therefore no breakdown potentials were observed. 3. Comparing the rupture potentials, Ti and Ti alloy had the high(:st value (because their break-down potentials were not observed in this study potential range ) followed by Co-Cr-Mo alloy and stainless steel (316L). So , the corrosion resistance of titanium was cecellent, Co-Cr-Mo alloy slightly inferior and stainless steel (316L) much less. 4. The contact current density sinks faster than any other galvanic couple in the case of Ti/gold alloy. 5. Ag-Pd alloy coupled with Ti yielded high current density in the early stage. Furthermore, Ti became anodic. 6. Ti/Ni-Cr alloy showed a relatively high galvanic current and a tendency to increase.

• Land and Housing Review
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• v.4 no.2
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• pp.133-144
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• 2013

It is commonplace to refer to the Nordic countries of Sweden, Norway, Denmark, Finland and Iceland as a distinctive and homogenous welfare regime. As far as social housing is concerned, however, the institutional heritage of the respective countries significantly frames the ways in which social housing is understood, regulated and subsidized, and, in turn, how housing regimes respond to the general challenges to the national welfare states. The paper presents a historical institutionalist approach to understanding the diversity of regime responses in the modern era characterized by increasing marketization, welfare criticism and internationalization. The aim is to provide outside readers a theoretically guided empirical insight into Scandinavian social housing policy. The paper first lines up the core of the inbuilt argument of historical institutionalism in housing policy. Secondly, it briefly introduces the distinctive ideal typical features of the five housing regimes, which reveals the first internal distinction between the universal policies of Sweden and Denmark selective policies of Iceland and Finland. The Norwegian case constitutes a transitional model from general to selective during the past quarter of a decade. The third section then concentrates on the differences between Denmark, Sweden and Norway in which social housing is, our was originally, embedded in a universal welfare policy targeting the general level of housing quality for the entire population. Differences stand out, however, between finance, ownership, regulation and governance. The historical institutional argument is, that these differences frame the way in which actors operating on the respective policy arenas can and do respond to challenges. Here, in this section we lose Norway, which de facto has come to operate in a residual manner, due to contemporary effects of the long historical heritage of home ownership. The fourth section then discusses the recent challenges of welfare criticism, internationalization and marketization to the universal models in Denmark and Sweden. Here, it is argued that the institutional differences between the Swedish model of municipal ownership and the Danish model of independent cooperative social housing associations provides different sources of resistance to the prospective dismantlement of social housing as we know it. The fifth section presents the recent Danish reform of the governance model of social housing policy in which the housing associations are conceived of as 'dialogue partners' in the local housing policy, expected to create solutions to, rather than produce problems in social housing areas. The reform testifies to the strategic ability of the Danish social housing associations to employ their historically grounded institutional relative independence of the public system.

• Journal of Family Resource Management and Policy Review
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• v.25 no.4
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• pp.1-14
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• 2021

This study was conducted to examine the realistic problems of flexible work arrangements, which was a representative policy for work-family balance, based on a review of its effect and influence on double-income couples who were actual users of the system. In this study, an in-depth interview with three double-income couples, totaling 6 parents, with preschool children was conducted on the experience of their flexible work arrangements, and the purposes of the study were to figure out their experienced positive effectiveness and the problems with the difficulty of using the system and to look for their solutions. For the data analysis of the study, it was organized into three high categories and nine low ones by reviewing the entire data on the basis of the frame structured in the derived data through the interview and categorizing the subjects by area. The derived analysis results were changes in households, social and cultural perspectives, and demand for policy and social economic changes. This study is significant in the sense that the perspectives and voice of the actual users of flexible work arrangements have been reflected in the study, and in the future, we expect that it will provide justification and persuasive power for the improvement of flexible work arrangements and serve as basic data for establishing policy directions and support.

• Journal of the Microelectronics and Packaging Society
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• v.25 no.4
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• pp.75-81
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• 2018

The effect of $Ar-N_2$ plasma treatment on Cu surface as one of solutions to realize reliable Cu-Cu wafer bonding was investigated. Structural characteristic of $Ar-N_2$ plasma treated Cu surface were analyzed using X-ray diffraction, X-ray photoelectron spectroscopy, atomic force microscope. Ar gas was used for a plasma ignition and to activate Cu surface by ion bombardment, and $N_2$ gas was used to protect the Cu surface from contamination such as -O or -OH by forming a passivation layer. The Cu specimen under high Ar partial pressure plasma treatment showed more copper oxide due to the activation on Cu surface, while Cu surface after high $N_2$ gas partial pressure plasma treatment showed less copper oxide due to the formation of Cu-N or Cu-O-N passivation layer. It was confirmed that nitrogen plasma can prohibit Cu-O formation on Cu surface, but nitrogen partial pressure in the $Ar-N_2$ plasma should be optimized for the formation of nitrogen passivation layer on the entire surface of Cu wafer.

• The Journal of the Korea Contents Association
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• v.21 no.4
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• pp.77-87
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• 2021

Smart Factory refers to a factory that can be controlled by itself with an intelligent factory that improves productivity, quality and customer satisfaction by combining the entire process of manufacturing and production with digital automation solutions. The manufacturing industry around the world is rapidly changing, with Germany, Europe, and the United States at the center. In order to cope with such changes, the Korean government is also implementing a policy to spread the supply of smart factories for small and medium-sized companies, and related ministries and agencies such as the Ministry of Commerce, Industry and Energy, the Ministry of SMEs and Venture Business, the Korea Institute of Technology and Information Promotion, and local technoparks, as well as large companies such as Samsung, SK and LG are actively investing in smart manufacturing projects to support smart factories[1]. Factory Automation (FA) construction has many issues regarding the connection of heterogeneous equipment. The most difficult aspect of configuring various communications from various equipment is the reason. Although it may not be known if there are standards or products made up of the same company, it is not easy to build equipment that is old, up-to-date, and different use environments through a series of communications. To solve this problem, we would like to propose a method of communication using Modbus, one of FieldBus, which is one of the many industrial devices of PLC, a representative facility control system, and is used as a communication standard.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.5
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• pp.162-170
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• 2021

The Smart City Living Lab is becoming important as a local innovation platform to develop urban solutions. In January 2018, the 4th industrial innovation committee, which was a direct subordinate from the president, empathized citizens' participation and their roles within the Smart City [Urban Innovation and Future Growth Engine-Creating Smart City Strategy]. This was the starting point of the living lab. The central government and local governments have been promoting various types of living labs to encourage citizens to participate. On the other hand, due to the lack of systematic concepts and theories for practicing and structuring living labs, the practice is not performed well. This study aimed to develop systematic approaches and implementation methods of the public-led Smart City Living Lab. The Full-cycle Smart City living Lab model was designed by integrating smart city living lab work processes, as suggested in the standards of the national land plan, double design diamond framework, which is a type of innovative design methodology, and design thinking process. The entire cycle Smart City living lab model requires four components to practice the living lab, such as framework, module, process, and methodologies. In the future, this model is expected to be incorporated in the Smart City Living Lab.

• Korean small business review
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• v.41 no.1
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• pp.53-73
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• 2019

Recently, as the number of shopping facilities has increased, such as complex shopping malls, warehouse type superstores, large fashion outlets, and so on, the conflicts over the opening of large stores between neighboring municipalities are increasing. However, current regulations on the opening of large-scale stores, such as the impact analysis on commercial area, do not adequately reflect the characteristics of new type shopping facilities. In this study, we tried to suggest a rational policy alternative with more realistic suitability by analyzing the characteristics of 'regional shopping facilities' beyond the scope of the municipalities, and analyzing the impact on the regional merchants. The main results of the study are summarized as follows. First, unlike previous researches, which are limited to small business sector, this study presents the results of comprehensively comparing and analyzing the impact on the detailed sectors of the whole distribution market, including the large distribution sector and online distribution sector. Second, in this study, we calculated the total (average) amount of market penetration rate of existing shopping facilities by the entire regional shopping facilities in the Seoul metropolitan area, and this is considered to be of great value in relation to the recognition of problems at the whole level of the metropolitan area and the search for alternative solutions.

• Geophysics and Geophysical Exploration
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• v.1 no.2
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• pp.127-135
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• 1998

The Born approximation is widely used for solving the complex scattering problems in electromagnetics. Approximating total internal electric field by the background field is reasonable for small material contrasts as long as scatterer is not too large and the frequency is not too high. However in many geophysical applications, moderate and high conductivity contrasts cause both real and imaginary part of internal electric field to differ greatly from background. In the extended Born approximation, which can improve the accuracy of Born approximation dramatically, the total electric field in the integral over the scattering volume is approximated by the background electric field projected to a depolarization tensor. The finite difference and elements methods are usually used in EM scattering problems with a 2D model and a 3D source, due to their capability for simulating complex subsurface conductivity distributions. The price paid for a 3D source is that many wavenumber domain solutions and their inverse Fourier transform must be computed. In these differential equation methods, all the area including homogeneous region should be discretized, which increases the number of nodes and matrix size. Therefore, the differential equation methods need a lot of computing time and large memory. In this study, EM modeling program for a 2D model and a 3D source is developed, which is based on the extended Born approximation. The solution is very fast and stable. Using the program, crosshole EM responses with a vertical magnetic dipole source are obtained and the results are compared with those of 3D integral equation solutions. The agreement between the integral equation solution and extended Born approximation is remarkable within the entire frequency range, but degrades with the increase of conductivity contrast between anomalous body and background medium. The extended Born approximation is accurate in the case conductivity contrast is lower than 1:10. Therefore, the location and conductivity of the anomalous body can be estimated effectively by the extended Born approximation although the quantitative estimate of conductivity is difficult for the case conductivity contrast is too high.