• New Physics: Sae Mulli
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• v.68 no.11
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• pp.1183-1191
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• 2018

The plasmon behaviors in a superlattice of $GaAs/Al_xGa_{1-x}As$ multiple quantum wells with a half-parabolic confining potential due to different dielectric interfaces are studied under magnetic and electric fields perpendicular and parallel to the superlattice axis by using a previously published theoretical framework. From the density-density correlation functions by considering the intrasubband and the inter-subband transitions under the random phase approximation, we calculate the dispersion energies of the surface and the bulk states as functions of the composition of the multiple quantum well structure and of the magnetic field strength and the average electric field strength over the quantum well. The Raman intensities for various magnetic field strengths and average electric field strengths over the quantum well are also obtained as a function of the energy of the incoming light for these states.

• The KIPS Transactions:PartA
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• v.14A no.2
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• pp.77-84
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• 2007

The intima media thickness(IMT) of the carotid artery from B mode ultrasound images has recently been proposed as the most useful index of individual atherosclerosis and can be used to predict major cardiovascular events. Ultrasonic measurements of the IMT are conventionally obtained by manually tracing interfaces between tissue layers. The drawbacks of this method are the inter and intra observer variability and its inefficiency. In this paper, we present a multiresolution snake method combined with the dynamic programming, which overcomes the various noises and sensitivity to initialization of conventional snake. First, an image pyramid is constructed using the Gaussian pyramid that maintains global edge information with smoothing in the images, and then the boundaries are automatically detected in the lowest resolution level by minimizing a cost function based on dynamic programming. The cost function includes cost terms which are representing image features and geometrical continuity of the vessel interfaces. Since the detected boundaries are selected as initial contour of the snake for the next level, this automated approach solves the problem of the initialization. Moreover, the proposed snake improves the problem of converging th the local minima by defining the external energy based on multiple image features. In this paper, our method has been validated by computing the correlation between manual and automatic measurements. This automated detection method has obtained more accurate and reproducible results than conventional edge detection by considering multiple image features.

• Journal of KIISE:Software and Applications
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• v.33 no.1
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• pp.32-43
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• 2006

Enterprise JavaBeans (EJB) has been accepted for supporting Component-Based Development (CBD). A component is a large-grained reuse unit consisting of several objects; however, an enterprise bean in EJB is a unit of atomic object and so multiple enterprise beans should be composed to support larger-grained reuse. Therefore, we need practical methods for designing and implementing components with EJB. In this paper, we propose instructions and techniques for designing CBD elements with EJB constructs. That is, we define methods for designing and implementing single and composite components, white- and black-box components, multiple interfaces, and variability mechanism in EJB platform. We evaluate the proposed method by performing a case study and comparing the characteristics of CBD components with the method. Consequently, the method is supposed to improve reusability, applicability, portability of components in EJB platform.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37B no.11
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• pp.975-983
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• 2012

Multi network interface has become common phenomenon for mobile devices such as smart phone which has 3G, LTE-advanced, WiFi. Consequently, there are researches for a transmission strategies using multiple paths below on end-to-end connection. MPTCP which is proposed and being standardized by the IETF as a new transport protocol can perform concurrent multipath transfer using multiple network interfaces. However, current MPTCP has performance degradation when it use heterogeneous networks which have quite different network characteristics. Therefore, this paper proposes the packet scheduling scheme and receiver-based recovery scheme to reduce the performance degradation due to reordering problem. Also, simulation results show that the proposed scheme can improve throughput and retransmission performance.

• Journal of The Korean Association of Information Education
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• v.14 no.4
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• pp.489-496
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• 2010

Since the specifications of public services in broadcasting-telecommunication convergence environment are not standardized, the public services should be developed and presented by each IPTV service provider, and therefore it is worried that public organizations and IPTV service providers may invest in the public services redundantly, which are managed inefficiently. To resolve those problem, in this paper, the service and network interfaces among multiple public organizations and multiple IPTV service providers and the interactive VOD-type public service providing system of one source multi-use based on ACAP-J are proposed. The proposed system can be utilized in the standard platform of the evolved new public services. And the used technologies can be utilized as a guide for the development of new services.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.8 s.350
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• pp.25-34
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• 2006

In this paper DynaMoNET is suggested as a novel IPv6-based multi-homed mobile network architecture which is composed of nested mobile ad hoc networks dynamically coming together through wireless personal area networks. Each ad hoc network has a mobile router which may work as a root mobile router instead of fixed mobile routers in a DynaMoNET. A root mobile router provides the reliable Internet connectivity for the entire mobile network. This paper includes a innovative handover protocol for multi-homed mobile networks, network switchover algorithm considering multiple decision factors, root mobile router election process based on token-based algorithm fast root mobile router discovery algorithm and fault avoidance mechanism to support reliable Internet connectivity. Finally the system architecture of a mobile router is given in detail.

• IE interfaces
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• v.25 no.2
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• pp.241-254
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• 2012

This paper studies the relationship between SCM(Supply Chain Management) metrics and corporate value (Tobin's Q) for manufacturing and wholesale/retail firms in Korea. Specifically, the multiple regression analysis is used to investigate the relationships 1) between inventory level, inventory turns, and days of inventory and Tobin's Q and 2) between cash-to-cash (C2C) cycle time including its components such as days of inventory, days sales outstanding, and days payable outstanding and Tobin's Q. The results indicate that there exist statistically significant negative relationships between inventory levels and days of inventory (DOI) and Tobin's Q. Also, we found that there exist commonly known negative correlations between days of raw materials inventory and days of work in process (WIP) inventory and Tobin's Q. For the C2C cycle time, we found that there -exists a statistically significant negative relationship between the C2C cycle time and Tobin's Q. Also, we found that there exist commonly known correlations between the two components of C2C cycle time and Tobin's Q such as the negative for DOI and days sales outstanding. This study clearly shows the negative relationship in general between inventory levels and corporate value and between C2C time and corporate value, and this kind of result has not been found by previous studies in Korea.

• Journal of the Korea Society for Simulation
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• v.16 no.1
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• pp.21-29
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• 2007

In this paper, we present a method of detecting the boundary of the intima-media complex for automated measurement based on dynamic programming from carotid artery B-mode ultrasound images and then show the experimental results. We apply the dynamic programming for determining the optimal locations that a cost function is minimized. The cost function includes cost terms which are representing image features such as intensity, intensity gradient and geometrical continuity of the vessel interfaces. Moreover, we improve the boundary continuity by applying the B-spline to smooth the rough boundary due to noise such as speckle, dropout and weak edges. The proposed method has obtained more accurate reproducible results than conventional edge-detection by considering multiple image features and ensures efficient automated measurement by solving the problems of the inter- and intra-observer variability and its inefficiency due to manual measurement.

• The KIPS Transactions:PartD
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• v.17D no.1
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• pp.9-16
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• 2010

Web service mashup bacomes one of the important web application development methods. This paper considers a client based mashup, where a page interfaces many service methods asynchronously. Browser systems execute callbacks when the corresponding reply arrives, possibly concurrent to user interface actions. In this case, callbacks and user interface actions share data memory and screen. Moreover, when the user is able to send another request before the previous ones have replied, the shared resource problem becomes more complicated. In order to solve the multiple requests problem, our contributions are as follows. First, we modeled a mashup page with user actions and callbacks, and we presented several types of callbacks. Secondly, concurrency condition is defined between callbacks and user actions in terms of shared resources, and the test method is presented. Also, we proposed the serialization approach to guarantee the safe execution of callbacks. Finally, we applied the proposed concurrency condition on XForms language and extended the XForms browser to implement the proposed approach. The prototype implementation showed that the proposed approach helps enhancing user experience on mashup pages.

• Journal of KIISE:Information Networking
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• v.36 no.3
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• pp.163-172
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• 2009

Various terminals equipped with multiple interfaces may receive services from wireless networks when they pass through the overlaid heterogeneous networks, and thus the vertical handovers across the wireless networks increases, which will become a big problem in the network resource management. This problem can be efficiently solved by common radio resource management (CRRM). In this paper, we propose two operation algorithms based on network selection jointly with vertical handover as the key CRRM strategies. When a new user tries to get services, the CRRM can choose the best target network according to the proposed Integrated Network Selection Algorithm. When the network cannot satisfy the request from the new users, the proposed Integrated Vertical Handover Algorithm moves existing users to neighborhood networks to accommodate new users. The performance of the proposed algorithms has been validated through extensive simulations.