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A Study on the Effect of Changes in Oil Price on Dry Bulk Freight Rates and Intercorrelations between Dry Bulk Freight Rates (국제유가의 변화가 건화물선 운임에 미치는 영향과 건화물선 운임간의 상관관계에 관한 연구)

  • Chung, Sang-Kuck;Kim, Seong-Ki
    • Journal of Korea Port Economic Association
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    • v.27 no.2
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    • pp.217-240
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    • 2011
  • In this study, vector autoregressive and vector error correction models in the short-run dynamics are considered to analyze the effect of the changes in international crude oil prices on Baltic dry index, Baltic Capesize index and Baltic Panamax index, and the intercorrelations between Capesize and Panamax prices, respectively. First, using the vector autoregressive model, the changes in international crude oil price have a statistically significant positive effect for Capesize at lag 1, for Panamax a significant negative effect at lag 3 and a significant positive effect for Baltic dry index at lag 1. From the impulse response analysis, the international crude oil price causes Baltic dry index to increase in the sort-run and the effect converges on the mean after 3 months. Second, using the vector error correction model, the empirical results for the spillover effects between Capesize and Panamax markets provide that in the case of the deviation from a long-run equilibrium the Panamax price is adjusted toward decreasing. The increases in freight rates of the Capesize market at lag 1 lead to increase the freight rates in Panamax market at present. The Panamax responses from the Capesize shocks increase rapidly for 3 months and the effect converges on the mean after 5 months. The Capesize responses from the Panamax shocks are relatively small, and increase weakly for 3 months and the effect disappears thereafter.

A Study on the Acceptance Decision Factors for Mobile Easy Payment Services in Digital Convergence Media Ara: Focusing Samsung Pay (디지털융합미디어시대 모바일 간편 결제서비스 수용결정요인에 관한 연구: 삼성페이를 중심으로)

  • Kim, Cha-Keun;Kim, Joung-Gun;Choi, Seong-Jhin
    • Journal of Digital Convergence
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    • v.15 no.4
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    • pp.213-221
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    • 2017
  • The purpose of this study was to examine the acceptance decision factors for mobile easy payment services focused on samsung pay. To attain these purpose, the subjects for data were 229 university students. The data were analyzed by path analysis using SPSS 21 program and AMOS program. The results were as follows: First, Perceived ease of use influenced positively on mobile easy payment service attitude. Second, Perceived usefulness influenced positively on mobile easy payment service attitude. Third, Perceived ease of use influenced positively on intention of continuous use. Fourth, Perceived usefulness influenced positively on intention of continuous use. Fifth, Attitude influenced positively on intention of continuous use. Sixth, Perceived risk influenced not significantly on intention of continuous use. This study identified the acceptance decision factors for mobile easy payment services as perceived ease of use, perceived usefulness and attitude.

Fabrication of high purified zirconium dioxide (ZrO2) and stabilized zirconia (TZP: tetragonal zirconia polycrystal) powders (고순도 산화지르코늄(ZrO2) 및 안정화 지르코니아 (TZP: tetragonal zirconia polycrystal) 분말제조)

  • 최의석
    • Proceedings of the Korea Association of Crystal Growth Conference
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    • 1996.06b
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    • pp.55-85
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    • 1996
  • 지르코니아 분말은 ZrO2 결정상이 온도변화에 따라 부피변화를 수반하는 상전이변태를 나타낸다. 단사정 ZrO2가 110$0^{\circ}C$에서는 정방정으로, 2$700^{\circ}C$ 내외에서는 입방정으로 결정구조가 가역적으로 변한다. 이 ZrO2에 금속산화물을 고용시키면 형석 (CaF2:Florite)형의 입방정 결정구조가 실온에서도 안정하게 존재하게 된다. 안정화제 산화물은 caO, MgO등 2가 산화물외에 3가 또는 4가의 금속산화물로서 Sc2O3, Y2O3, Sm2O3, Nd2O3, Gd2O3, Y2O3, CeO2 등이며 이들은 금속이온의 원자가가 변하기 쉬운 희토류 산화물이다. 안정화 지르코니아는 형석형 결정구조이며 결정화학적으로 보면 금속양이온이 산소이온에 대해서 정육면체형의 8배위를 하고 있다. 이때 이온반경비(양이온/음이온)에 따라 Zr+4자리와 O-2자리의 격자위치와 모양이 형성되므로 비틀어진 정육면체구조이건 이상적인 정육면체 형석구조를 이룬다. 이는 지르코니아의 결정상의 2상-3상인 부분안정화 지르코니아다결정체(PSZ : partially stabilized zirconia)이거나 단일상-2상인 정방정 지르코니아다결정체(TZP : tetragonal zirconia polycrystal)의 결정구조를 가지는데 기인한다. PSZ는 주로 MgO, CaO를 안정화제로 고용시켜 입방정 영역에서 소결하고 이를 다시 입방정과 정방정의 상 영역에서 열처리하여 입방정 입자내부에 정방정을 석출 형성시킨 것이며 TZP는 Y2O3 및 CeO2를 고용시켜 PSZ와 다르게 일반적인 상압소결한 정방정 결정상의 미립자이다. 산화지르코늄 분말은 지르콘사에서 열분해시킨 지르코늄소결.융해괴(caustic fusion clinker)를 산처리하여얻어진 지르코늄산용액(zirconyl acid solution : cloride, sulfide, nitride 등)으로부터 제조된다. 고순도 산화지르코늄은 용액 결정석출법에 의해 ZrOCl2.8H2O, 5ZrO2.3SO3.15H2O, ZrO(NO3)2.xH2O 등의 지르코늄 수화물만을 재결정화시킨 것으로부터 얻을 수 있으며 이 지르코늄염 수용액으로부터 입자미세구조를 효과적으로 제어하여 산화지르코늄 및 안정화 지르코니아 분말제조가 가능하다. 안정화 지르코니아 분말은 ZrO2와 안정화산화물의 고용을위하여 가열처리를 필요로 하며 일정온도에서 최적상태로 숙성하므로서 2가지 상(phase) 이상의 고용체를 가지게 된다. 안정화 지르코니아 분말은 고용처리온도를 낮추고 효과적으로 생성시키기 위해서는 지르코늄 및 안정화제염을 혼합하고 습식 직접합성하여 저온에서 고용체의 합해진상 영역을 생성시키는 것이다. 이는 지르코니아 원료분말의 미세구조를 제어하므로서 가능하며 이때 화학성분조성과 크기형태가 균일하게 분포된 입자분말을 얻을 수 있다.

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Study on $CdIn_{2}Te_{4}$ single crystal growth and electrical characteristics ($CdIn_{2}Te_{4}$ 단결정 성장과 전기적 특성)

  • 홍광준
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.6 no.1
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    • pp.32-43
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    • 1996
  • A $CdIn_{2}Te_{4}$ single crystal was grown by modified veritical bridgman method. The $CdIn_{2}Te_{4}$ single crystal was evaluated to be tetragonal by the powder method. The $CdIn_{2}Te_{4}$ single crystal was confirmed to be grown with its c axis along the lengthe of the boule by the Laue reflection method. Hall effect of $CdIn_{2}Te_{4}$ single crystal was estimated by van der pauw method from 293 K to 30 K. Hall data of the sample perpendicular to c axis was $n=8.75{\times}10^{23}electrons/m^{3},\;R_{H}=7.14{\times}10^{-5}m^{3}/C,\;{\sigma}=176.40{\omega}^{-1}m^{-1},\;{$\mu}=3.41{\times}10^{-2}m^{2}/V.s$ and the sample parallel to c axis was $n=8.61{\times}10^{23}electrons/m^{3},\;R_{H}=7.26{\times}10^{-5}m^{3}/C,\;{\sigma}=333.38{\omega}^{-1}m^{-1}\;and\;{$\mu}=2.42{\times}10^{-2}m^{2}/V.s$ for room temperature. The value of Hall coefficient on sample perpendicular or parallel to c axis were positive. There $CdIn_{2}Te_{4}$ single crystal was p-type semiconductor.

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Synthesis of Single Crystalline Analcime and Its Single-crystal Structure, |Na0.94(H2O)|[Si2.06Al0.94O6]-ANA: Determination of Cation Sites, Water Positions, and Si/Al Ratios (결정성 아날심(|Na0.94(H2O)|[Si2.06Al0.94O6]-ANA)의 합성 및 단결정구조: 양이온 및 물 분자의 위치, Si/Al 비의 결정)

  • Seo, Sung-Man;Suh, Jeong-Min;Ko, Seong-Oon;Lim, Woo-Taik
    • Journal of the Korean Chemical Society
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    • v.55 no.4
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    • pp.570-574
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    • 2011
  • Large colorless single crystals of analcime with diameters up to 0.20 mm have been synthesized from gels with the composition of $3.00SiO_2$ : $1.50NaAlO_2$ : 8.02NaOH : $454H_2O$ : 5.00TEA. The fully $Na^+$-exchanged analcime have been prepared with aqueous 0.1 M NaCl (pH adjusted from 6 to 11 by dropwise addition of NaOH). The single-crystal structure of hydrated $|Na_{0.94}(H_2O)|[Si_{2.06}Al_{0.94}O_6]$-ANA per unit cell, a=13.703(3) ${\AA}$, has been determined by single-crystal X-ray diffraction technique in the orthorhombic space group Ibca at 294 K. The structure was refined using all intenties to the final error indices (using only the 1,446 reflections for which $F_o$ > $4{\sigma}(F_o))R_1/wR_2$ = 0.054/0.143. About 15 $Na^+$ ions are located at three nonequivalent positions and octahedrally coordinated. The chemical composition is $Na_{0.94}(H_2O)Si_{2.06}Al_{0.94}O_6$. The Si/Al ratio of synthetic analcime is 2.19 determined by the occupations of cations, 14.79, in the single-crystal determination work.

An Empirical Study on Safety Education and Training for Dangerous Goods and Hazardous Materials Handlers in Busan New Port Terminals and Hinterland Logistics Centers (위험물취급자 안전교육훈련에 관한 실증연구 -부산신항만 터미널 및 배후단지 물류센터를 대상으로-)

  • Shin, Chang-Hoon;Jo, Hyun-Jun;Wang, GaoFeng
    • Journal of Korea Port Economic Association
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    • v.34 no.2
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    • pp.31-50
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    • 2018
  • This study implemented an empirical analysis of education and training for dangerous goods and hazardous materials handlers on the Busan New Port terminals and hinterland logistics centers using a Structural Equation Modeling (SEM) in combination with the formative model and reflective model, from the viewpoint of the supply chain. An effect size analysis was also conducted. The results of the empirical analysis show that Training Environment and the Atmosphere of Education have a positive influence on the Educational Expectation of hazardous material handlers, and the Educational Expectation has a positive influence on the Education and Training Program and Transfer of Education Training. Likewise, the Education and Training Program has a positive influence on the Transfer of Education Training and Result of Education and Training. Furthermore, the Transfer of Education Training has a positive influence on the Result of Education and Training. The Result of Education and Training has a positive influence on the Present State of hazardous material management. According to the results of the effect size analysis, the following parameters represented a great effect: the Atmosphere of Education to the Education Expectation, the Education Expectation to the Education and Training Program, the Transfer of Education Training to the Result of Education and Training, and the Result of Education and Training to the Present State of Dangerous Goods Management. The results of this study provided various suggestions for related practices.

Investigation of Harmful Microorganisms and Physiological Characteristics of Mycelia in the Bed-log of Shiitake Strains Showing Low Fruit-body Productivity (버섯 발생이 부진한 표고골목 내부균사의 생리적 특성 및 해균 조사)

  • Bak, Won-Chull;Lee, Bong-Hun;Ryu, Sung-Ryul;Ka, Kang-Hyeon
    • The Korean Journal of Mycology
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    • v.34 no.2
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    • pp.88-91
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    • 2006
  • Attempts were made to investigate the conditions of mycelia of one low-temperature type strain and one high-temperature type strain of shiitake showing poor fruit-body formation in bed-log, and to survey harmful microorganisms formed on the log surface in Gapyung County, Korea. When tested the growing ability of mycelia, the low-temperature type strain showed ca. 1.1% decrease compared with preserved original strain. And, the high-temperature type one showed ca. 8.0% decrease. The growth of isolated mycelia was tested in sawdust medium. The high-temperature type strain showed ca. 10.8% decrease compared with original strain, and the low-temperature type one showed ca. 25.1% decrease. Weight reduction rate was investigated. The high-temperature strain showed ca. 20.1% decrease and the low-temperature one ca. 19.0%. When compared with non-treatment, original high-temperature type strain showed 107.0% decrease, the isolated high-temperature type strain 49.5%, original low-temperature type one 85.4%, isolated low-temperature type one 50.0%. As the results of confrontation culture, the high-temperature type strain and the low-temperature type one were same as the original ones, respectively. And, in the bed-logs, Hypoxylon truncatum, Coriolus versicolor, Inonotus xeranticus, Daedaleopsis tricolor, Graphostroma platystoma, two species of Myxomycetes, Trichoderma sp. Hypoxylon fragiforme, H. howeianum, and Nitschkia confertula were observed as harmful microorganisms, and the bed-logs were not in good condition.

Study on Sanjungjapgok(山中雜曲) written by Kim Deuk-yeon(金得硏) (김득연의 <산중잡곡> 연구 - 지수정 경영과 관련하여 -)

  • Nam, Dong-Geol
    • Sijohaknonchong
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    • v.43
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    • pp.123-148
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    • 2015
  • Kim Deuk-yeon(金得硏), who lived at the age of Chosun Dynasty, was the person who kept the parents's will of not serving as a government officias even though he had the ability of serving those positions. He made his composition at the Jisujeong(止水亭), a kind of pavilion which he had built, and the Sijo(時調) Sanjungjapgok(山中雜曲) is one of those compositions. This sugggestes that Sanjungjapgok has a close relation with the Jisujeong(止水亭) which he opreated on his own. So the purpose of this study is focused on analyzing the Sanjungjapgok based on his goal of operating the Jisujeong. The middle age of Chosun dynasty was the era when the pavilion had been prevail even to the average aristocrats who stayed just in local area. Kim Deuk-yeon seems to have had a great endeavor of operating his own pavilion; he had prepared to build Jisujeong for about 30 years. This resulted in his affection of the Jisujeong, which caused him to spend the last part of his life there. Sanjungjapgok consists of 49 pieces of peom and seems to have been written after compositing Jisujeongga(止水亭歌). Even though it has the same title, it doesn't have lots of relations for us to regard this as a Yeonsijo(聯詩調). But this also has the properties of Yeonsijo, whoch contatins 14 Yeonjaksijo(聯作時調) composed of Yeonsijo which has 2 to six lines. The subject of the Sanjungjapgok can be classified as a four major parts: appreciating the nature, study, gathering to make the poem, and taking a rest while satisfied with his own situation. These four properties reflect the function of the private pavilion. In the light of these four properties, I noticed that there were some contents dealing with the private pavilion. Given his social status, I was able to confirm that he had the considerable satisfaction with his life of operating the private pavilion, which was reflected by the Sanjungjapgok.

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산수과 학습 보조 자료의 효율적인 활용 방안

  • 정창현;양인환;양순렬;신성균
    • The Mathematical Education
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    • v.29 no.2
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    • pp.117-139
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    • 1990
  • 본 연구는 국민 학교 산수 익힘책의 효율적인 활용 방안을 찾는 데 목적이 있으며, 이를 위하여 선행 및 문헌 연구와 "산수 익힘책"의 활용 실태를 조사하였다. 본 연구에서 수행한 연구 내용을 요약하면 다음과 같다. 가. 이론적 배경 연구 및 산수 익힘책의 개발 방향 문헌과 선행 연구를 통하여 보조 교과서의 특성에 따를 활용 방안 및 보조 교과서의 학습 내용에 따른 틀용 방안을 이론적으로 고찰하였고, "산수 익힘책"의 개발 방향 및 그 특색에 대하여 조사하였다. 나. 활용 실태 조사 사용하고 있는 "산수 익힘책"의 활용 실태를 파악하여, 활용 방안을 마련하는 기선 자료를 수집하기 위함이며, 조사 내용은 다음과 같다. 1) 조사 내용 (1) 교사의 측면에서 ㆍ "산수 익힘책"의 도움 정도 ㆍ "산수 익힘책"의 수업 시간에의 활응 목적, 방법 ㆍ "산수 익힘책"의 활용시 편리성 ㆍ 흥미성 ㆍ 활용 시기 ㆍ 가정 학습으로 부과시의 목적 ㆍ 문제 풀이 결과 확인자 ㆍ 교육 과정 반영 정도 ㆍ 개선점 (2) 학부모의 측면에서 ㆍ"산수 익힘책"의 활용 목적 ㆍ "산수 익힘책"의 활용 정도 ㆍ "산수 익힘책"의 도움 정도 ㆍ 학부모의 역할 정도 ㆍ "산수 익힘책"에 대한 학생의 흥미도 ㆍ "산수 익힘책"의 개선점 2) 조사 도구 조사 내용에 대하여 국민 학교 1, 2, 3학년 담임 교사용과 학부모용의 질문지를 각각 작성하여 전문가의 검토를 거쳐 "산수 익힘책"의 활용에 관한 실태 조사지를 개발하였다. 이 때, 각 학년별 교사용끼리, 학부모용끼리의 질문지의 문항은 서로 같게 하였으며 교사용은 25문항, 학부모용은 16문항으로 구성하였다. 다. 활용 방안 구안 "산수 익힘책"의 개발 방향과 "산수 익힘책"의 활용 실태 조사에 기초하여 산수 익힘책의 효율적인 활용 방법을 수업 절차에 따라 구분하였다. 수업 절차는 여러 가지 형태가 있지만 본 연구에서는 KEDI의 수업 과정 일반 모형에 준하여 산수 익힘책의 활용 방법을 구안하였다. 라. 활용 방안을 구안하였다. 1) 적용 목적 구안된 "산수 익힘책"의 활용 방안의 현장 적용은 활용 방안의 질을 높이려는 대에 중요한 목적이 있다. 적용 결과는 현장 적용 가능성을 판단할 수 있는 입증 자료가 될 수 있을 뿐만 아니라, "산수 익힘책" 관심을 가지고 있는 교사나 연구자에게 학력 향상 가능성에 대한 경험적 근거를 제시함으로써 중요한 시사를 줄 수 있을 것이다. 2) 적용 결과 전체적으로 적응 수업이 실시된 지 3주후 부터는 활용 방안에 익숙해져 "산수 익힘책"을 효과적으로 활용할 수 있었다. 그 뿐만 아니라 자율학습시 학생들 스스로가 상호 확인을 하고, 서로 결손이 있는 부분을 가르쳐 주는 협동 학습이 이루어졌다.

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Influence of pH and Ionic Strength on Treatment of Radioactive Boric Acid Wastes by Forward Osmosis Membrane (정삼투막에 의한 붕산함유 방사성 폐액 처리를 위한 pH 및 이온강도 영향)

  • Choi, Hye-Min;Hwang, Doo-Seong;Lee, Kune-Woo;Moon, Jei-Kwon
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.11 no.3
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    • pp.193-198
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    • 2013
  • In general, boron recovery of 40-90% could be achieved by Reverse Osmosis (RO) membranes in neutral pH condition. As an emerging technology, Forward Osmosis (FO) membrane has attracted growing interest in wastewater treatment and desalination. The objective of this study is to evaluate the possibility of the boron removal in radioactive liquid waste by FO. In this study, the performance of FO was investigated to remove boron in the simulated liquid waste as the factors such as pH, osmotic pressure, ionic strength of solution, etc. The pH of feed solution is a major operating parameter which strongly influences to the permeation of boron and more than 80% of boron content can be separated when conducted at pH values less than 7. The water flux is not influenced but the boron flux and permeation rate tends to decrease in the low salt concentration of 1,000 mg/L. The boron flux increases linearly, but the permeation ratio of reducing boron is nearly constant even with changes in the draw solution concentration.