• Korean Chemical Engineering Research
• /
• v.62 no.1
• /
• pp.99-104
• /
• 2024

In this study, a carbon coated hollow silicon (HSi/C) composite material was prepared for anode material of high-capacity lithiun-ion battery. Hollow silica (HSiO₂) was synthesized by the Stöber method with CTAB (N-Cetyltrimethylammonium bromide). The HSi/C anode composite was manufactured by carbon coating after magnesiothermic reduction of HSiO₂. The physical and electrochemical characteristics of the prepared anode materials were investigated based on CTAB amount. In the FE-SEM analysis, it was found that the HSiO₂ particle size increased as CTAB amount decreased, but shell thickness decreased. The HSi/C composites exhibited high initial discharge capacities of 1866.7, 2164.5 and 2188.6 mAh/g with various CTAB ratios (0.5, 1.0, 1.5), respectively. After 100 cycles of charge-discharge, 0.5-HSi/C demonstrated a high reversible capacity of 1171.3 mAh/g and a capacity retention of 70.9%. Electrochemical impedance spectroscopy (EIS) was employed to analyze the impedance characteristics, and it revealed that 0.5-HSi/C showed more stable resistance characteristics than HSi/C composites with other CTAB amount over 20 cycles.

• Journal of Cadastre & Land InformatiX
• /
• v.54 no.1
• /
• pp.33-48
• /
• 2024

This study aims to establish the scope and statistics of the K-address information industry in Korea, estimating its size and prospects and estimates the economic effects through K-address information industry based on Input-Output analysis. Considering the characteristics and sectoral structure of the K-address information industry, the study delineates the scope and specific sectors, constructing sectoral statistics linked to the KSIC and the Bank of Korea's industrial classification. The study estimates the sectoral industry size, taking into account potential markets. Furthermore, it analyzes the economic impact of each sector within the K-address information industry. To figure out the economic effects, the study conducts Input-Output analysis by setting the K-address information industry as an exogenous sector in the input-output table. The results indicate that the overall size of the K-address information industry is estimated to grow from 406.1 billion KRW in 2021 to 3.65 trillion KRW in 2030. The economic effects of the K-address information industry vary by sector, emphasizing the importance of synergies and integration with related sectors, particularly those with significant inducement effects in high value-added manufacturing and service sectors. Furthermore, the industry's sensitivity to economic fluctuations is evident through the input-output analysis of inter-industry chain effects.

• Journal of the Mineralogical Society of Korea
• /
• v.5 no.2
• /
• pp.109-121
• /
• 1992

For the purpose of mineralogical and chemical study on the topazes from various localities of world(Brzail, China, India, Nigeria and Sri Lanka), electron microprobe analysis(EPMA), neutron activation analysis(NAA), X-ray diffractometry, Raman spectroscopy, etch test, scanning electron microscopy, refractive index, specific gravity, fluid inclusion were performed. The chemical composition in topaz was discussed along with its physical and structural properties. Variations in the unit-cell dimension and physical properties of topaz were found to have a close relations in the unit-cell dimension and physical properties of topaz were found to have a close relationship with extent of substitution of $OH^-\;for\;F^-$. According to neutron activation analyses, the trace elements had no effects on the physical properties of topaz. Raman spectra showed that the peaks of topaz were different in intensity from one locality to another. Etching defects in topaz includes negative crystal defect o point-bottom pit(India, Nigeria) and net work defect of curl-bottom pit(Brazil, China). Fluid inclusions in topaz may be classiffied into liquid $CO_2$-bearing inclusion, gaseous inclusion, halite, sylvite-bearing inclusion and liquid inclusion. The results of this study can be useful to devising artificial coloring methods for topaz with different mineralogical compositions.

• Journal of Korea Technology Innovation Society
• /
• v.14 no.4
• /
• pp.1024-1049
• /
• 2011

Korea has accomplished rapid industrial development based on the manufacturing industry. However, the growth potential has been slowing down lately due to some reasons including low employment creation rates. Also, competitions in the manufacturing industry with China and developing countries in Asia are constantly intensified. Advanced countries maintain economic growth based on the competitiveness secured by changing its industrial structure into service oriented economy. Accordingly Korean government announced various policies to promote service industry and stimulate R&D activity for the advancement of knowledge based service industry. For promoting R&D of private firm, R&D center accreditation system for knowledge based service firm is going to be introduced. However, the accreditation system needs to be revised because it was established based solely on manufacturing business. Under the existing system, subject firms for government support are selected based on R&D activities. However in service area, the difference between R&D activity and business activity is indistinctive due to its nature so that the range of subject firms can be expanded too much. So it is more practical to select major service businesses and operate the system with selected businesses. There also should be proper logic to select major service business from the whole service businesses. We have to consider Koean industrial structure which is heavily dependent on manufacturing business and has weak competitiveness in service business when preparing the logic. In this paper, we study how to set up the range of service business and the requirements for R&D center accreditation. For this, this paper analyzed the ripple effect on the economy of service businesses based on input-output analysis, R&D activity and capability to put the resource for R&D. Based on the analysis result, we suggest methods to screen subject companies for R&D center accreditation among service business and present possible measures on manpower and physical requirement for service industry's R&D center accreditation system.

• Journal of Korea Port Economic Association
• /
• v.37 no.3
• /
• pp.117-128
• /
• 2021

In order for the users (shipping firms and shippers) and suppliers (stevedoring firms) in the container terminal industry to win-win, it is necessary to have some appropriate diverse market conditions for the industry. This study analyses the basic conditions and demand and supply characteristics of the industry and investigates the market performance of Busan container ports. First, this article analyses the basic characteristics of demand and supply. As the demand characteristics, there are five ones such as 1) exogeneity of demand, 2) function as export/import transportation and hub for transshipment, 3) increase of users' bargaining power, 4) high substituting elasticity, 5) reduction of volume growth. As the supply characteristics, there are seven ones such as 1) inelasticity of supply, 2) homogeneity of stevedoring services, 3) over-supply, 4) adoption of cutting-edge stevedoring technology, 5) scale economy and impossibility of storage, 6) labor market rigidity, 7) enhancing port's role in SCM. In addition, this study conducts the so-called structure-conduct-performance analysis. For the structure analysis, 1) lacks of scale economy in stevedoring companies, 2) high entry barrier, 3) strengthening of shipping firms' bargaining power, 4) transitory permission scheme for tariff are analyzed. For the conduct analysis, 1) price discrimination between export/import and transshipment, 2) mid-term length of terminal use contract, 3) continuous investment in equipment, 4) low level of cooperation among terminal operating firms are derived. For the performance analysis, 1) inequality in profitability, 2) reduction of export/import cost, 3) delay in adopting cutting-edge technology, 4) idle equipment are analyzed. Following this logical flow, the hypothesis that the market structure influences the market conduct is tested based on the actual dataset. As a future agenda in the conclusion, this article recommends the so-called port industrial policy.

• Journal of Distribution Science
• /
• v.10 no.2
• /
• pp.29-41
• /
• 2012

This paper undertakes a conceptual review of transaction cost to broaden the understanding of the transaction cost analysis (TCA) approach. More than 40 years have passed since Coase's fundamental insight that transaction, coordination, and contracting costs must be considered explicitly in explaining the extent of vertical integration. Coase (1937) forced economists to identify previously neglected constraints on the trading process to foster efficient intrafirm, rather than interfirm, transactions. The transaction cost approach to economic organization study regards transactions as the basic units of analysis and holds that understanding transaction cost economy is central to organizational study. The approach applies to determining efficient boundaries, as between firms and markets, and to internal transaction organization, including employment relations design. TCA, developed principally by Oliver Williamson (1975,1979,1981a) blends institutional economics, organizational theory, and contract law. Further progress in transaction costs research awaits the identification of critical dimensions in which transaction costs differ and an examination of the economizing properties of alternative institutional modes for organizing transactions. The crucial investment distinction is: To what degree are transaction-specific (non-marketable) expenses incurred? Unspecialized items pose few hazards, since buyers can turn toalternative sources, and suppliers can sell output intended for one order to other buyers. Non-marketability problems arise when specific parties' identities have important cost-bearing consequences. Transactions of this kind are labeled idiosyncratic. The summarized results of the review are as follows. First, firms' distribution decisions often prompt examination of the make-or-buy question: Should a marketing activity be performed within the organization by company employees or contracted to an external agent? Second, manufacturers introducing an industrial product to a foreign market face a difficult decision. Should the product be marketed primarily by captive agents (the company sales force and distribution division) or independent intermediaries (outside sales agents and distribution)? Third, the authors develop a theoretical extension to the basic transaction cost model by combining insights from various theories with the TCA approach. Fourth, other such extensions are likely required for the general model to be applied to different channel situations. It is naive to assume the basic model appliesacross markedly different channel contexts without modifications and extensions. Although this study contributes to scholastic research, it is limited by several factors. First, the theoretical perspective of TCA has attracted considerable recent interest in the area of marketing channels. The analysis aims to match the properties of efficient governance structures with the attributes of the transaction. Second, empirical evidence about TCA's basic propositions is sketchy. Apart from Anderson's (1985) study of the vertical integration of the selling function and John's (1984) study of opportunism by franchised dealers, virtually no marketing studies involving the constructs implicated in the analysis have been reported. We hope, therefore, that further research will clarify distinctions between the different aspects of specific assets. Another important line of future research is the integration of efficiency-oriented TCA with organizational approaches that emphasize specific assets' conceptual definition and industry structure. Finally, research of transaction costs, uncertainty, opportunism, and switching costs is critical to future study.

• Journal of Intelligence and Information Systems
• /
• v.23 no.3
• /
• pp.1-27
• /
• 2017

It is known that the economic sentiment index and macroeconomic indicators are closely related because economic agent's judgment and forecast of the business conditions affect economic fluctuations. For this reason, consumer sentiment or confidence provides steady fodder for business and is treated as an important piece of economic information. In Korea, private consumption accounts and consumer sentiment index highly relevant for both, which is a very important economic indicator for evaluating and forecasting the domestic economic situation. However, despite offering relevant insights into private consumption and GDP, the traditional approach to measuring the consumer confidence based on the survey has several limits. One possible weakness is that it takes considerable time to research, collect, and aggregate the data. If certain urgent issues arise, timely information will not be announced until the end of each month. In addition, the survey only contains information derived from questionnaire items, which means it can be difficult to catch up to the direct effects of newly arising issues. The survey also faces potential declines in response rates and erroneous responses. Therefore, it is necessary to find a way to complement it. For this purpose, we construct and assess an index designed to measure consumer economic sentiment index using sentiment analysis. Unlike the survey-based measures, our index relies on textual analysis to extract sentiment from economic and financial news articles. In particular, text data such as news articles and SNS are timely and cover a wide range of issues; because such sources can quickly capture the economic impact of specific economic issues, they have great potential as economic indicators. There exist two main approaches to the automatic extraction of sentiment from a text, we apply the lexicon-based approach, using sentiment lexicon dictionaries of words annotated with the semantic orientations. In creating the sentiment lexicon dictionaries, we enter the semantic orientation of individual words manually, though we do not attempt a full linguistic analysis (one that involves analysis of word senses or argument structure); this is the limitation of our research and further work in that direction remains possible. In this study, we generate a time series index of economic sentiment in the news. The construction of the index consists of three broad steps: (1) Collecting a large corpus of economic news articles on the web, (2) Applying lexicon-based methods for sentiment analysis of each article to score the article in terms of sentiment orientation (positive, negative and neutral), and (3) Constructing an economic sentiment index of consumers by aggregating monthly time series for each sentiment word. In line with existing scholarly assessments of the relationship between the consumer confidence index and macroeconomic indicators, any new index should be assessed for its usefulness. We examine the new index's usefulness by comparing other economic indicators to the CSI. To check the usefulness of the newly index based on sentiment analysis, trend and cross - correlation analysis are carried out to analyze the relations and lagged structure. Finally, we analyze the forecasting power using the one step ahead of out of sample prediction. As a result, the news sentiment index correlates strongly with related contemporaneous key indicators in almost all experiments. We also find that news sentiment shocks predict future economic activity in most cases. In almost all experiments, the news sentiment index strongly correlates with related contemporaneous key indicators. Furthermore, in most cases, news sentiment shocks predict future economic activity; in head-to-head comparisons, the news sentiment measures outperform survey-based sentiment index as CSI. Policy makers want to understand consumer or public opinions about existing or proposed policies. Such opinions enable relevant government decision-makers to respond quickly to monitor various web media, SNS, or news articles. Textual data, such as news articles and social networks (Twitter, Facebook and blogs) are generated at high-speeds and cover a wide range of issues; because such sources can quickly capture the economic impact of specific economic issues, they have great potential as economic indicators. Although research using unstructured data in economic analysis is in its early stages, but the utilization of data is expected to greatly increase once its usefulness is confirmed.

• Korean Journal of Environment and Ecology
• /
• v.25 no.2
• /
• pp.156-165
• /
• 2011

It is selected seven sites for marine algal flora and community structure and investigated seasonally from December 2008 to November 2009 in Gogunsan Islands, the west coast of Korea. A total of 58 species including 10 green, 16 brown and 32 red algae were collected and identified. Among these species, 11 species were found throughout the year. Annual mean biomass in dry weight were 213.8 g $m^{-2}$ at Sinsido 1, 143.1 g $m^{-2}$ at Sinsido 2, 133.3 g $m^{-2}$ at Sinsido 3, 164.0 g $m^{-2}$ at Munyeodo, 116.9 g $m^{-2}$ at Seonyudo, and 145.1 g $m^{-2}$ at Jangjado. Maximum biomass was recorded in Sinsido 1, and minimum mean biomass was Sinsido 4. The dominant species based on biomass were Sargassum thunbergii, Ulva pertusa, Sargassum fusiforme and Corallina pilulifera. S. thunbergii was the representative alga occurred at all seasons. The flora investigated could be classified into six functional groups such as coarsely branched form (46.6%), filamentous form (27.6%), sheet form (17.2%), thick leathery form (3.4%), jointed calcareous form (3.4%) and crustose form (1.7%). The R/P, C/P and (R+C)/P value reflecting flora characteristics were 0.33~0.75, 1.11~2.50, 1.47~3.25, respectively. Diversity index (H') and dominance index (DI) indicated that stability of seaweed community of Gogunsan Islands was unstable and environmental conditions were bad. According to multidimensional scaling (MDS) and cluster analysis, Gogunsan Islands were divided into three distinct groups. The first group was Sinsido 2, Sinsido 3, Seonyudo and Muyeodo and the second group comprised Sinsido 1 and Jangjado and the other was Sinsido 4 due to meaningful difference in similarity.

• Economic and Environmental Geology
• /
• v.38 no.2 s.171
• /
• pp.187-196
• /
• 2005

Structural sites which cations can occupy in garnet structure are centers of the tetrahedron, octahedron, and distorted cube sharing edges with the tetrahedron and octahedron. Among them, the size of cation occuping at tetrahedral site (the center of tetrahedron) is closely related with the size of a unit cell of garnet. Accordingly, garnet containing iron with relative large ionic radii in tetrahedral site can be considered as a promising matrix for the immobilization of the elements with large ionic radii, such as actinides in radioactive wastes. We synthesized several garnets with the batch composition of $Ca_{1.5}GdCe_{0.5}ZrFeFe_3O_{12}$, and studied their properties and phase relations under various conditions. Mixed samples were fabricated in a pellet form under a pressure of $200{\~}400{\cal}kg/{\cal}cm^2$ and were sintered in the temperature range of $1100\~1400^{\circ}C$ in air and under oxygen atmospheres. Phase identification and chemical analysis of synthesized samples were conducted by XRD and SEM/EDS. In results, garnet was obtained as the main phase at $1300^{\circ}C$, an optimum condition in this system, even though some minor phases like perovskite and unknown phase were included. The compositions of garnet and perovskite synthesized from the batch composition of $Ca_{1.5}GdCe_{0.5}ZrFeFe_3O_{12}$ were ranged $[Ca_{l.2-1.8}Gd_{0.9-1.4}Ce_{0.3-0.5}]^{VIII}[Zr_{0.8-1.3}Fe_{0.7-1.2}]^{VI}[Fe_{2.9-3.1}]^{IV}O_{12}$ and $Ca_{0.1-0.5}Gd_{0.0-0.8}Ce_{0.1-0.5}\;Zr_{0.0-0.2}Fe_{0.9-1.1}O_3$, respectively. Ca content was exceeded and Ce content was depleted in the 8-coordinated site, comparing to the initial batch composition. This phenomena was closely related to the content of Zr and Fe in the 6-coordinated site.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.7
• /
• pp.504-509
• /
• 2018

The purpose of this study was to manufacture a high-performance titanium yellow pigment. Anatase type $TiO_2$ was the skeleton of the pigment and $Sb_2O_3$ is used as the color assistant for the coloring agent, $Cr_2O_3$. Mixed raw materials for the pigment were $TiO_2$(98%), $Sb_2O_3$(99.5%), and $Cr_2O_3$(99.5%). The raw materials were mixed by a dry process and crystallized by calcination at $1,000{\sim}1,200^{\circ}C$. The crystalline material was pulverized in a Jar Mill under $1{\mu}m$ by a wet process and dried for 12 hours at $100^{\circ}C$. The pigment was finally made by a fine grinding process. To determine the best temperature for calcination, 4 temperature sections ($1000^{\circ}C$, $1100^{\circ}C$, $1150^{\circ}C$, and $1200^{\circ}C$) were set up. The X-ray diffraction peak of the rutile crystalline structure was highest at $1,150^{\circ}C$. The yellow ceramic pigment, which has the rutile structure, was applied for coating materials. The synthesized pigments underwent a discoloration tests on the acid resistance, alkaline resistance, weather resistance and heat resistance. In addition, a detection test on harmful heavy metals ($Cr^{+6}$) was done. The resulting values (${\Delta}E$) of the weather resistance test (2000hr), acid resistance test, alkaline resistance test, and heat resistance test were 0.74, 0.16, 0.07 and 0.29. The resulting value for heavy metals testing was 34ppm.