• Journal of the Korean Graphic Arts Communication Society
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• v.18 no.2
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• pp.55-68
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• 2000

Joint photographic experts group (JPEG) is a standard still-image compression technique, established by the international organization for standardization (ISO) and international telecommunication standardization sector (ITUT). The standard is intended to be utilized in the various kinds of color still imaging systems as a standard color image coding format. Because JPEG is a lossy compression, the decompressed image pixel values are not the same as the value before compression. Various distortions of JPEG compression and JPEG recompression has been reported in various papers. The Image compressed by JPEG is often recompressed by same type compression method in JPEG. In general, JPEG is a lossy compression and the quality of compressed image is predicted that is varied in according to recompression Q-factor. In this paper, four difference color samples(photo image, gradient image, gradient image, vector drawing image, text image) were compressed in according to various Q-factor, and then the compressed images were recompressed according to various Q-factor once again. As the result, this paper evaluate the variation of image quality and file size in JPEG recompression and recommed the optimum recompression factor.

• Proceedings of the Korean Printing Society Conference
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• 2000.04a
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• pp.17-24
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• 2000

The Joint Photographic Experts Group (JPEG) is a standara still-image compression technique, established by the International for Standardization (ISO) and International Telecommunication Standardization Sector (ITUT). The standard is intended to be utilized in the various kinds of color still imaging systems as a standard color image coding format. Because JPEG is a lossy compression, the decompressed image pixel values are nto the same as values before compression. Image of JPEG compression is often made to JPEG recompression at saving to apply JPEG compression of color image. In general, JPEG is a lossy compression and compression image is predicted to be varied image quality according to recompressed Q-factor. Various distortions of JPEG compression and JPEG recompression has been reported in previous paper. In this paper, we compress four difference color samples (photo image, gradient image, vector drawing image, text image) according to various Q-factor, and then compressed images are recompressed according to various Q-factor once again. As the results, we inspect variation of quality and file size of recompressed color image, and ensure the optimum recompression factor.

• International Commerce and Information Review
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• v.7 no.4
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• pp.435-453
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• 2005

This paper suggests several strategies for promoting Trade and Foreign Direct Investment cooperation to the Korean government and companies as follows ; For Korean government, its trade policy would be given much weight on the import from the Vietnam in the early developing stage. This import could be compensated and increased with the counter export of Korean products like the industrial goods. For Korean companies, they would make haste to invest and develop the abundant energy and natural resources in Vietnam. Their desirable strategies would be moving small scale projects into large ones, production partnerships with the foreign developed and experienced companies, and international joint ventures for using inward FDI incentives. The long range vision and perseverance are indispensable for promoting trade and foreign direct investments between and Korea and Vietnam and both parties' win-win results and development in the end.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.21 no.4
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• pp.90-105
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• 2013

As witnessed in September 11 attacks, air terrorism is often the most effective means to achieve their goals, and thereby requires a sophisticated level of security measures. Moreover, considering the nature of air transportation, the prevention of air terrorism demands a wide range of international cooperation and joint efforts such as timely sharing of information related to air terrorism (such as latest terror techniques and list of terrorists) between nations, International Air Transport Association (IATA) and International Civil Aviation Organization (ICAO) As most air terrorism can be effectively prevented through security and search activities in airports, this study has focused on researching security measures and issues in major airports around the world, along with the potential measures to improve them. To achieve this effect, this paper offers solutions to preventing air terrorism by exploring appropriate responses to various type of air terrorism, deployment of advanced security and search equipment, techniques to identify terrorists, R&D on equipments to physically take down terrorists and systematic improvements on airport security search process.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.10
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• pp.4835-4855
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• 2018

In this paper, we study the sparse signal recovery that uses information of both support and amplitude of the sparse signal. A convergent iterative algorithm for sparse signal recovery is developed using Majorization-Minimization-based Non-convex Optimization (MM-NcO). Furthermore, it is shown that, typically, the sparse signals that are recovered using the proposed iterative algorithm are not globally optimal and the performance of the iterative algorithm depends on the initial point. Therefore, a modified MM-NcO-based iterative algorithm is developed that uses prior information of both support and amplitude of the sparse signal to enhance recovery performance. Finally, the modified MM-NcO-based iterative algorithm is used to estimate the time-varying sparse wireless channels with temporal correlation. The numerical results show that the new algorithm performs better than related algorithms.

• The Journal of Fisheries Business Administration
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• v.46 no.3
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• pp.15-29
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• 2015

The illegal, unreported and unregulated fishing can be properly regulated only if fishing activities, transhipment and landing of illegally caught fish, and processing of fish at sea involved in it are integrally managed. To do this, flag States, port States, coastal States, market States and relevant regional fisheries management organizations shall closely cooperate. In addition, fishing boats involved in IUU fishing often ignore requirements of safety of navigation so that they could be exposed to more causes of incidents and could have less chances to be rescued. Then, it seems to be necessary for the regulation on IUU fishing to include a certain consideration of strengthening safety of those ships. International Maritime Organization(IMO) has developed and implemented international rules for the safety of shipping. IMO has cooperated with Food and Agricultural Organization on IUU fishing since 2000 and the third joint meeting is scheduled in November 2015. This paper reviews the recommendations adopted in the previous meetings, and the measures actually taken as a result of the cooperation and, in particular, focus on the additional roles of IMO for the eradication of the IUU fishing.

• International Journal of Advanced Culture Technology
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• v.8 no.2
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• pp.270-276
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• 2020

In this paper, we analyze the buyer's joint pricing and lot-sizing model in a two-stage supply chain consisting of the supplier, the buyer and the customer. It is assumed that the supplier will permit a certain fixed period for settling the amount the buyer owes to him for the items supplied in order to stimulate the demand for the product. Generally, credit transactions would have a positive effect to the buyer. The availability of credit transactions from the supplier effectively reduces the cost of holding stocks for the buyer and therefore, the buyer has a lot of price options to choose his sales price for a customer in anticipation of increased the customer's demand and, as a result, it will appear to increase the buyer's inventory levels. On the other hand, in the case of decaying products in which their utility decay over time, the decaying rate with time may be expected to reduce inventory levels. In this regard, we need to analyze how much the length of credit period and the decaying rate affect the buyer's pricing and lot-sizing policy. For the analysis, we consider the situation where the customer's demand is represented as a linearly decreasing function of the buyer's sales price. From this perspective, we formulate the buyer's annual net profit and analyze the effect of the length of credit period and decaying rate of the product on the buyer's inventory policy numerically.

• International Journal of Korean Welding Society
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• v.4 no.1
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• pp.61-66
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• 2004

In this paper, the effect of underfill packages was investigated by numerical approach and experimental test. Reliability improvement was the main issue in the package technology. BGA, CSP and small-sized packages, have problems due to concentration of the stress in solder joints. One of the latest technologies to overcome is underfill encapsulant. Mainly, it is noticed the effect of the underfill in the packages. The predicted thermal fatigue lifes are performed by Coffin-Manson's equation with ANSYS (v.5.62). Also, thermal cycle test during from 218K to 423K was included. Finally we could find that underfill greatly reduce the concentration stress in solder joint, thus the fatigue life was improved than without underfill.

• International Journal of Korean Welding Society
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• v.4 no.1
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• pp.30-37
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• 2004

There have been continuous efforts on automating welding processes. This automation process could be said to fall into two categories, weld seam tracking and weld quality evaluation. Recently, the attempts to achieve these two functions simultaneously are on the increase. For the study presented in this paper, a vision sensor is made, a vision system is constructed and using this, the 3 dimensional geometry of the bead is measured on-line. For the application as in welding, which is the characteristic of nonlinear process, a fuzzy controller is designed. And with this, an adaptive control system is proposed which acquires the bead height and the coordinates of the point on the bead along the horizontal fillet joint, performs seam tracking with those data, and also at the same time, controls the bead geometry to a uniform shape. A communication system, which enables the communication with the industrial robot, is designed to control the bead geometry and to track the weld seam. Experiments are made with varied offset angles from the pre-taught weld path, and they showed the adaptive system works favorable results.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.2 no.2
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• pp.139-145
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• 2002

In this paper, we proposed an intelligent digital redesign method for a class of fuzzy-model-based controllers, effective fur stabilization of continuous-time nonlinear systems. The TS fuzzy model is used to expend the results of the digital redesign technique to nonlinear systems. The proposed method utilized the recently developed LMI technique to obtain a digitally redesigned fuzzy-model-based controller. The intelligent digital redesign problem is converted to equivalent problem, and the LMI method is used to find the digitally redesigned fuzzy-model-based controller. The stabilization conditions of TS fuzzy model are derived for stabilization in the sense of Laypunov stability. In order to demonstrates the effectiveness and feasibility of the proposed controller design methodology, we applied this method to the single link flexible-joint robot arm.