• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.3
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• pp.185-191
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• 2022

This paper proposed a division algorithm of performance complexity $O{\frac{n(n+1)}{2}}$ for a change-making problem(CMP) in which polynomial time algorithms are not known as NP-hard problem. CMP seeks to minimize the sum of the x_j number of coins exchanged when a given amount of money C is exchanged for c_j,j=1,2,⋯,n coins. Known polynomial algorithms for CMPs are greedy algorithms(GA), divide-and-conquer (DC), and dynamic programming(DP). The optimal solution can be obtained by DP of O(nC), and in general, when given C>2ⁿ, the performance complexity tends to increase exponentially, so it cannot be called a polynomial algorithm. This paper proposes a simple algorithm that calculates quotient by dividing upper triangular matrices and main diagonal for k×n matrices in which only j columns are placed in descending order of c_j of n for c_j ≤ C and i rows are placed k excluding all the dividers in c_j. The application of the proposed algorithm to 39 benchmarking experimental data of various types showed that the optimal solution could be obtained quickly and accurately with only a calculator.

• The KIPS Transactions:PartC
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• v.12C no.4 s.100
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• pp.589-596
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• 2005

The objective of this paper lies in the design and implementation of a home gateway supporting live video streaming which flows from the Non-SIP video camera in home to the mobile SIP device outside. We developed the home gateway on the OSGi framework and employed the RTC technology which embeds an SIP stack so that the multimedia session can be established from the home device to the mobile user outside. And also we developed an RTC bundle to manage the session and a virtual capture device driver to read the video stream from the Non-SIP video camera in the home network, and installed them on the home gateway. Finally, we constructed the experimental environment that has the windows messenger as the SIP mobile device and an AXIS 2100 UPnP video camera as a video source, and then tested if the session establishment to the mobile user from the camera and live video streaming work well between them.

• The KIPS Transactions:PartC
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• v.12C no.1 s.97
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• pp.105-110
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• 2005

With the proliferation of multimedia group applications, the construction of multicast trees satisfying QoS requirements is becoming a problem of prime importance. In this paper, we study the delay- and delay variation-bounded multicast tree (DVBMT) problem which is NP-complete. The problem is to construct a spanning tree for destination node, which has the minimized multicast delay variation, and the delay on the path from the source to each destination is bounded. A solution to this problem is required to provide decent real-time communication services such as on-line games, shopping, and teleconferencing. Performance comparison shows that the proposed scheme outperforms DDVCA which is known to be effective so far in any network topology. The enhancement is up to about $3.6{\%}{\~}11.1{\%}$ in terms of normalized surcharge for DUVCA. The time complexity of our algorithm is $O(mn^2)$.

• The KIPS Transactions:PartC
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• v.9C no.6
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• pp.883-892
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• 2002

Mobile IP has been designed only to maintain communications as they move from place to place, so it doesn't guarantee Quality of Service (QoS). QoS in mobile IP is important to provide multimedia and real-time applications services in mobile environment, and it is closely related to handoff delay. Therefore, handoff delay problem is actively studied to guarantee QoS as a main issue in mobile IP research area. In this paper, we suggest SNMP Information-based routing that adds keyword management method to Information-based routing in active network in order to resolve such a problem, and then suggest QoS controlled handoff based on SNMP Information-based routing. After modeling of suggested method and existing handoff method, simulations are carried out with NS -2 for performance evaluation. The results of simulations show the some improvement on handoff delay, and therefore on QoS improvement.

• The KIPS Transactions:PartC
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• v.9C no.5
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• pp.733-742
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• 2002

It has been known that the host mobility feature has very significant impact on the QoS (Quality of Service), which is usually required to a real-time multimedia application. The existing QoS support mechanisms to provide the real-time services to fixed network environment, like as RSVP, are inadequate to accommodate the mobile hosts which can frequently change their point of attachments to the fixed network. So, MRSVP (Mobile RSVP) protocol has been proposed to reduce the impacts of host mobility on QoS guarantees, in which a mobile host needs to make advance resource reservations at multiple locations it may possibly visit during the lifetime of the connection. This paper proposes a dynamic dual anchor node (DDAN) architecture which integrates the MRSVP and RSVP tunnel, in addition to the Mobile IP Regional Registration protocol. By limiting the resource reserved in local area, it preserves the lower level of resource reservation, but provides approximately the same degree of QoS support as the existing MRSVP.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.24 no.2
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• pp.105-111
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• 2024

This paper deals with the minimum linear arrangement(MinLA) of a lattice graph, to which an approximate algorithm of linear complexity O(n) remains as a viable solution, deriving the optimal MinLA of 31,680 for 33×33 lattice. This paper proposes a partitioning arrangement algorithm of complexity O(1) that delivers exact solution to the minimum linear arrangement. The proposed partitioning arrangement algorithm could be seen as loading boxes into a container. It firstly partitions m rows into r₁,r₂,r₃ and n columns into c₁,c₂,c₃, only to obtain 7 containers. Containers are partitioning with a rule. It finally assigns numbers to vertices in each of the partitioned boxes location-wise so as to obtain the MinLA. Given m,n≥11, the size of boxes C₂,C₄,C₆ is increased by 2 until an increase in the MinLA is detected. This process repeats itself 4 times at maximum given m,n≤100. When tested to lattice in the range of 2≤n≤100, the proposed algorithm has proved its universal applicability to lattices of both m=n and m≠n. It has also obtained optimal results for 33×33 and 100×100 lattices superior to those obtained by existing algorithms. The minimum linear arrangement algorithm proposed in this paper, with its simplicity and outstanding performance, could therefore be also applied to the field of Very Large Scale Integration circuit where m,n are infinitely large.

• Journal of electromagnetic engineering and science
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• v.6 no.2
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• pp.83-91
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• 2006

In this paper, we develop space-time(ST) Rake receivers for Time Division Synchronous Code Division Multiple Access(TD-SCDMA) base stations(BS). The beamforming of BS transforms the uplink MIMO channel space into many sub-sectors' channels to be nearly orthogonal, thus, well established 1-D Rake technology can be used to TD-SCDMA base station to construct ST Rake, which simplified the system's implementation as well as enlarged users' capacity by the beamforming. The construction and capacity of MIMO sub-sectors by multi-beamforming have been presented. The proposed ST Rake algorithm include the multi-beamforming algorithm for MIMO sub-sectors and classical 1-D Rake algorithm. The calculating formulas for interference plus noise ratio(SINR) and bit error rate(BER) have been derived. Simulations verify that the proposed ST Rake receiver for BS is effective, and the BS systems can get higher system capacity and can be of better performance than presented TD-SCDMA systems.

• Journal of Nutrition and Health
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• v.37 no.4
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• pp.310-315
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• 2004

The purposes of this study were to: a) develop the quality assessment tool of Web-based Instruction (WBI) for nutrition education, b) evaluate the operated WBI (NutriZone) by this tool, and c) do the feasibility study about quality assessment tool for WBI by establishing the instruction and operating strategies. The developed quality assessment tool of WBI for nutrition education was divided into three categories of instruction design, contents and support ＆ operation. And a total of forty items were measured by Likert 5 point scale, computed as one point per item, and amounted to forty points in all. As a result of evaluation, NutriZone got 21.79 out of 40 points and fulfillment rate of 54.5%. The IPA (Importance-Performance Analysis) was applied to establish the instruction and operating strategies, and nine items characterized as attractiveness, multimedia, and learner-initiative were in 'Doing Great, Keep It Up', and so it was regar-ded as program designed with concern in WBI's characteristics unlike the conventional face-to-face education. But twelve items such as 'Errors on switch to other screens are few.', 'Ready correction leads to be out of systemic error.', 'Highlight marks and moving pictures were used in sign of importance.' and etc. that got high importance and low performance needed to be focused in instructional strategy.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.43 no.4 s.310
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• pp.39-49
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• 2006

This paper proposes an efficient verification environment of PCI Express controller that is the future I/O interface. This verification environment consists of a test vector generator, a test bench, and two abstract memories. We also define the assembler set to generate the verification scenarios. In this paper, we propose the random test environment which consists of a random vector generator, a .simulator part, and a compare engine. This verification methodology is useful to find the special errors which are not detected by the basic-behavioral test and hardware-design test.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.8C
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• pp.801-805
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• 2009

The importance of high-speed networking is ever increasing to better support multimedia application such as video conferencing. It is crucial to synchronize the network so that the delay between computers on the network is minimized. In high-speed LAN, for example, most computers use clocks with almost same frequency to minimize the delay for data transmission. However, because of the deviation of transmitter's and receiver's clock frequency and phase difference there can be a metastability problem. Elasticity buffer is to provide a solution for this situation and this paper presents an implementation is a high-speed elasticity buffer.