• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.32A no.8
• /
• pp.19-30
• /
• 1995

For the efficient interconnection between SMDS and LAN, an interconnection protocol architecture in the router is proposed in this paper. A control method of xongestion which is produced by this interconnection of SMDS and LAN is also proposed. Especially, the SIP level 3 of SMDS is devided into CS-SIP3 sublayer and CLNAP sublayer in order to circumvent the problems which are producted by the protocol difference of two networks and to consider the interconnection with B-ISDN in the future. In this way, the interconnection of SMDS and LAN is transparentlly achieved through CLNAP layer, and the interconnection protocol architecture becomes simple. To test the performance of the router, amodel of interconnection protocol which is proposed by this paper is simulated using sliding window flow control. The simulation results show that the throughput of router is increased. The packet delay and the rate of packet discard are also decreased.

• Journal of the Korean Mathematical Society
• /
• v.48 no.3
• /
• pp.565-583
• /
• 2011

In this paper we provide characterizations for the Gromov hyperbolicity of some particular Denjoy domains and besides some sufficient conditions to guarantee or discard the hyperbolicity of some others. The conditions obtained involve just the lengths of some special simple closed geodesics in the domain. These results, on the one hand, show the extraordinary complexity of determining the hyperbolicity of a domain and, on the other hand, allow us to construct easily a large variety of both hyperbolic and non-hyperbolic domains.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.24 no.12
• /
• pp.1678-1682
• /
• 2000

In this article, the concept of gradient thickness is further extended to characterize the gradient behavior of the thermal and momentum boundary layer near a solid surface. The gradient thickness can replace the use of the conventional of the Nusselt and Reynolds numbers in terms of the gradient thickness provides a much easier grasp of the physical and practical meaning of the processes involved. Although there is no urgent need to discard the concept of the conventional convective heat transfer coefficient, the concept of the gradient thickness is believed to serve an efficient tool in helping students understand physics.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.7 no.3
• /
• pp.509-521
• /
• 2013

Impossible Differential Cryptanalysis (IDC) uses impossible differentials to discard wrong subkeys for the first or the last several rounds of block ciphers. Thus, the security of a block cipher against IDC can be evaluated by impossible differentials. This paper studies impossible differentials for Rijndael-like and 3D-like ciphers, we introduce methods to find 4-round impossible differentials of Rijndael-like ciphers and 6-round impossible differentials of 3D-like ciphers. Using our methods, various new impossible differentials of Rijndael and 3D could be searched out.

• Journal of Educational Research in Mathematics
• /
• v.8 no.2
• /
• pp.509-526
• /
• 1998

school mathematics is based on the premise that teacher have extensively complex mathematics content and pedagogical content knowledge to employ teaching to facilitate students' conceptualization of mathematics knowledge. In this paper we have presented the realities of teacher education program about several countries and three source area in teaching school mathematics. As a result we suggest that for developing mathematics teacher education First, communities have to hold teachers in high esteem due to confucian heritage. Second, our university have t provide one year internship for training for practices and the use of interactive multimedia simulation. Third, college courses have to help students discard misunderstanding knowledge and briefs about mathematics and pedagogy they bring to the university. Fourth, our country have to reform teacher education system. Fifth, the government have to pay the tuition costs for more students.

• Transactions of Materials Processing
• /
• v.8 no.6
• /
• pp.612-619
• /
• 1999

Internal and external defects of an inner pulley for automobile air conditioner are investigated in this study. Inner pulley is a part of compressor clutch assembly of automobile air conditioner. In cold forging of inner pulley, the design requirement are to keep the same height of the inner rib and outer one and to make uniform distribution of hardness in the forged product. At the end of the forging of inner pulley, the piping defect as an external defect begins to form at the back center of the billet. The internal crack as an internal defect also occur at the adiabatic shear band which usually has maximum ductile fracture value. It is important to predict when the internal and external defects occur during the deformation process, in order to minimize the amount of discard that is generated. The finite element simulations are applied to analyze the defects. The validity of the computational results are examined by experiments. These computational results are in good agreement with the experimental ones.

• The Korean Journal of Archival Studies
• /
• no.64
• /
• pp.5-25
• /
• 2020

The archives should not document the absence of labor records, but document the traces of workers' lives. In other words, it is the responsibility of the archive to reproduce the acts and sufferings of contingent workers with records, and to reveal the oppressive structure of capitalism based on them. Records representing the lives of contingent workers, such as labor manuals, should be at the core of records that symbolize the present, and archives should be documented. The archives should discard the illusion of neutrality.

• Proceedings of the Korean Information Science Society Conference
• /
• 2000.10c
• /
• pp.484-486
• /
• 2000

인터넷 비디오 방송 같은 멀티미디어 응용 프로그램들은 네트워크를 통한 비디오 전송을 필요로 한다. 그런데 네트워크 자원에 제약이 많은 경우에는 전송되는 비디오 스트림의 손실이 불가피하며 이러한 손실이 클라이언트나 네트워크에서 일어난다면 네트워크 자원의 낭비가 생기게 된다. 이에 본 논문에서는 제약이 많은 네트워크를 통해 계층적 인코딩이 적용된 비디오 스트림을 전송할 때 서버가 프레임 전체를 버리지 않고 가능하면 덜 중요한 계층만을 최적으로 버리는 선택적 계층 삭제 알고리즘을 제안하였다. 어떤 계층을 버리는데 드는 비용을 클라이언트 측에서 얻을 수 있는 QoS와 연관지어 볼 때, 제안하는 선택적 계층 삭제 알고리즘은 네트워크 자원 제약이 커질수록 기존의 선택적 프레임 삭제 알고리즘보다 높은 QoS를 보여주었다.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.29 no.1
• /
• pp.26-29
• /
• 2000

Major characteristics of brines produced from the salting process were compared among winter, spring, and summer (highland) Chinese cabbages. The soluble-solids contents of final brine were decreased to 87~90% of initial brine during salting process, and showed 16.3, 15.8, and 14.4$^{\circ}$Brix for winter, spring, and highland Chinese cabbages, respectively. The pHs showed similar changes during salting process from pH 8.40~8.63 for initial to pH 6.03~6.24 for final. The high salting(12.4~14%) of final brine needs dilution or reuse treatemnt before discard. The COD of final brine were increased to 39.6 ppm, 52.1 ppm, 37.7 ppm, respectively. During salting total microbial counts of final brine were increased ten times from those of the initial brines for all samples.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.26 no.9A
• /
• pp.1535-1541
• /
• 2001

TCP is the most widely-used transport layer protocol in current Internet, while ATM technology is used to increase the data communication speed at data link layer and network layer. In the TCP-over-ATM architecture, the most significant problems are (i) the partial packet discarding problem, and (ii) the TCP window timeout problem. Several approaches have been proposed to solve the partial packet discard problem and the timeout problem individually, but none of them considered the two problems together. In this paper, we propose an enhanced UBR+ scheme which supports fairness among the TCP connections using UBR+ scheme, and provides protection of damaged VC from the multiple packet losses in the same TCP sliding window. To analyze its performance, we simulate the proposed scheme using OPNET. The simulation results show that the proposed scheme supports fairness, and also increases the throughput by reducing the probability of multiple cell losses in the same TCP window.