• Korean Journal of Crystallography
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• v.14 no.2
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• pp.105-109
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• 2003

Electrical properties of Ni/Au/p-GaN and optical properties of epitaxial GaN MQW LED on sapphire were characterized. At 20 mA forward bias, GaN MQW emitted in the blue at 470 nm. Current-voltage (I-V) characteristics were decreased linearly with the annealing temperature. The resistivity of Ni/Au contacts was found by TLM measurements to be of device quality (2×10/sup -1/Ωㆍcm).

• The KSFM Journal of Fluid Machinery
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• v.4 no.4 s.13
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• pp.53-58
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• 2001

• Journal of Ocean Engineering and Technology
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• v.14 no.2
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• pp.117-120
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• 2000

In the Step of preliminary ship design a designer should decide a economic ship. The economic ship has the least building cost to a annual freight amount satisfying a given design condition That is RFR is minimum among alternatives.

• 수도
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• s.21
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• pp.15-23
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• 1980

• Journal of the Korea Society of Computer and Information
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• v.27 no.7
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• pp.187-194
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• 2022

LNG is known as the transitional energy source for the future eco-friendly, attracting enormous market attention due to global eco-friendly regulations, Covid-19 Pandemic, Russia-Ukraine War. In addition, since new LNG suppliers such as the U.S. and Australia are also diversifying, the LNG spot market is expected to grow. On the other hand, research on the LNG transportation market has been marginalized. Therefore, this study attempted to predict short-term LNG 160K spot rates and compared the prediction performance between artificial neural networks and the ARIMA model. As a result of this paper, while it was difficult to determine the superiority and superiority of ARIMA and artificial neural networks, considering the relative free of ANN's contraints, we confirmed the feasibility of ANN in LNG 160K spot rate prediction. This study has academic significance as the first attempt to apply an artificial neural network to forecasting LNG 160K spot rates and are expected to contribute significantly in practice in that they can improve the quality of short-term investment decisions by market participants by increasing the accuracy of short-term prediction.

• Korean Journal of Heritage: History & Science
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• v.52 no.4
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• pp.18-37
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• 2019

This study derived a method for establishing the chronology of cloud patterns by examining the arrangement of the treasure motifs in the cloud pattern used in the relevant pattern-decorated book covers of 89 Oegyujanggak Uigwe books, which are currently housed in the National Museum of Korea. The cloud pattern with a treasure motif was used in the covers of a total of 89 books from King Hyojong Gukjangdogam Uigwe (1659) to Sadoseja Garyedogam Uigwe (1744), spanning 86 years. First, to analyze the cloud pattern, it should be broken down into smaller parts to the extent that the different shapes of treasure motifs can be recognized. Secondly, the method of decoding the pattern is as follows: First, check whether the pattern is arranged in one or two directions from the vertex of the cloud's head, and determine the direction of the cloud tail. Then, decode the treasure motif's arrangement starting from the vertex of the cloud's head toward the direction the tail of manja is headed. Record the findings of this decoding process by categorizing them. Thirdly, as a result of the analysis, a total of 28 types of cloud patterns with treasure motifs were identified in 89 books. There were 45 types of treasure motifs used in such patterns. Finally, we have concluded that applying the method of decoding the treasure motif in the cloud pattern to portraits, excavated costumes, and various relics can be useful to establish the chronology of cloud patterns in the late Joseon period. The method suggested in this study is called 'The Reading Method of Chronology in Cloud Pattern with Treasure Motifs' (also 'Jeung-ha Cloud Pattern Reading Method').

• Journal of Korea Port Economic Association
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• v.27 no.2
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• pp.297-311
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• 2011

This paper deals with a strategic investment decision model for improving investment profit in shipping industry. Despite the quantitative expansion of Korean shipping business, many shipping firms have suffered financial difficulties due to financial and operating risks that result from the characteristics of capital-intensive business as well as of volatility of shipping markets. As a result, managers in charge of making an investment decision, particularly in tramper business sector, are required to take both financial and operating risk factors into consideration. Put it differently, managers are strongly recommended to avoid these risks by ship asset play; buy-low and sell-high, which results in considerable capital gain and cost reduction. In addition, managers in shipping industry are also recommended to consider the ship chartering investment alternative when the freight markets show extreme volatility as the case of 2008 triggered by sub-prime mortgage financial crisis in USA. For example, the BDI suffered plunging down from 1000 in 2008 to 100 in 2010. Consequently, the 4th largest shipping company in Korea, DAEHAN Shipping Co., has collapsed primarily due to excessive tonnage expansion during the peak time of bulk market. In sum, the strategic investment decision model, suggested in this paper, is designed to include such factors as capital gain by asset play, timely chartering for alternative shipping service, and optimization of operating profit by tonnage adjustment in accordance with change in the shipping markets concerned.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.7
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• pp.3000-3006
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• 2012

We investigate whether the belief in good luck of stock traders influences their satisfaction with and their loyalty to a stock trading service. In particular, we tested whether the online stock traders who have irrational beliefs in good luck (e.g., I am a lucky person) (1) are satisfied with their online stock trading service more strongly and (2) stay with it longer than the online stock traders who have rational beliefs in good luck (e.g., luck does not exist). We have tested satisfaction, loyalty, and belief in good luck among 412 online stock traders and tested our two hypotheses. Our findings contribute to the academic research on service satisfaction and loyalty as well as provide implications to online stock trading service providers.

• Journal of the Korea Society of Computer and Information
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• v.18 no.6
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• pp.37-45
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• 2013

In the absence of a single deterministic rule for the channel assignment problems, heuristic algorithms are predominantly employed to partly solve the problems. This paper thus proposes deterministic rules for the channel assignment problems. These deterministic rules have successfully yielded the optimal solution when applied to the Philadelphia's 9 case examples.

• Journal of Navigation and Port Research
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• v.42 no.6
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• pp.546-554
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• 2018

The Bulk market, unlike the line market, is characterized by stiff competition where certain ship or freight owners have no influence on freight rates. However, freights are subject to macroeconomic variables and economic external shock which should be considered in determining management or chartering decisions. According to the results analyzed by use of ARIMA Inventiom model, the impact of the financial crisis was found to have a very strong bearing on the BDI index. First, according to the results of the VEC model, the libor rate affects the BDI index negatively (-) while exchange rate affects the BDI index by positively (+). Secondly, according to the results of the VEC model's J ohanson test, the order ship volume affects the BDI index by negatively (-) while China's economic growth rate affects the BDI index by positively (+). This shows that the shipping company has moved away from the simple carrier and responded appropriately to changes in macroeconomic variables (economic fluctuations, interest rates and exchange rates). It is believed that the shipping companies should be more aggressive in its "trading" management strategy in order to prevent any unfortunate situation such as the Hanjin Shipping incident.