• The KIPS Transactions:PartC
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• v.10C no.5
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• pp.603-610
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• 2003

On the optical network, it is important to build restoration scheme capable to network survivability in preparation of potential failure on communication route. This paper analyze the existing schemes on restoration of failure on the optical network, and propose deferred commit scheme to improve resource utilization and management efficiency. Also, the transfer flow of messages needed for transferring restoration signal are presented in a concrete way and delay time required by shared mesh restoration scheme is explained in a substantial way. Simulation-based comparative analysis of various schemes is performed.

• Journal of Ginseng Research
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• v.13 no.2
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• pp.153-157
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• 1989

The characteristics of the areal parts, photosynthetic and respiration rates and stem color were examined in 1- to 5-year-old Green-stem, Violet-stem and Yellow-berry variant ginseng (Panax ginseng C.A. Meyer). The top characteristics, photosynthetic and respiration rates were not significantly different among the three variants. Selfed progency of the Green-stems variant plant produced only green stems, while the others produced green and violet stem in the seedling stage. These results showed that most of the top characteristics of the Green-stem variant were similar those of the Violet-stem and Yellow-berry variants with age.

• The Korean Journal of Food And Nutrition
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• v.17 no.4
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• pp.405-411
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• 2004

The sensory properties in Alaska pollack sikhae were compared in 3 different temperature conditions, 5$^{\circ}C$, 20$^{\circ}C$ and alternating temperature(stored at 5$^{\circ}C$ after 10 days of fermentation at 20$^{\circ}C$), respectively, during fermentation. The change of instrumental texture including hardness, cohesiveness, adhesiveness and chewiness increased and/or decreased without significant difference in the sikhae fermented at 5$^{\circ}C$ during fermentation. Three profiles, hardness, chewiness and cohesiveness in the sikhae fermented at 20$^{\circ}C$ increased up to 12 day and then decreased, whereas those in alternating temperature decreased significantly. From the acceptance test during fermentation, sikhae products fermented for 14 days at 5$^{\circ}C$, 9 days at 20$^{\circ}C$ and 13 days at alternating temperature were superior in sensory properties. The score more over 5 point in overall acceptance was maintained until 14 days in 5$^{\circ}C$, 9 days in 20$^{\circ}C$ and 13 days in alternating temperature, respectively, and particularly, alternating temperature condition was superior to the different temperature conditions. The sensory texture and overall acceptance had the high positive correlation with chewiness and taste, respectively. From the result of quantitative descriptive analysis, the intensities of acidic odor and taste in alternating temperature maintained and/or increased during 27 days of fermentation, whereas those in sikhae fermented at 5$^{\circ}C$ decreased. These results demonstrated that cold chain system such as alternating temperature was needed for shelf-life extension and producing of marketable Allaska pollack sikhae.

• The KIPS Transactions:PartC
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• v.17C no.5
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• pp.433-440
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• 2010

Energy efficiency, low latency and scalability for wireless sensor networks are important requirements, especially, the wireless sensor network consist of a large number of sensor nodes should be minimized energy consumption of each node to extend network lifetime with limited battery power. An efficient algorithm and energy management technology for minimizing the energy consumption at each sensor node is also required to improve transfer rate. Thus, this paper propose no-overlap multi-pass protocol provides for sensor data transmission in the wireless sensor network environment. The proposed scheme should minimize network overhead through reduced a sensor data translation use to searched multi-path and added the multi-path in routing table. Proposed routing protocol may minimize the energy consumption at each node, thus prolong the lifetime of the sensor network regardless of where the sink node is located outside or inside the received signal strength range. To verify propriety proposed scheme constructs sensor networks adapt to current model using the real data and evaluate consumption of total energy.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5C
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• pp.191-198
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• 2009

It has been reported in Korea that surface slope failures in weathered soil are mainly caused by downward infiltration due to rainfall. These failures are triggered by the deepening of the wetting band in soils accompanied by a decrease in matric suction induced by the water infiltration. So, a need exists that these trends of wetting path in gneiss weathered soils, which is commonly found in Korea, are assessed by phenomenological approach. In this paper, numerical analyses of unsaturated soil slope under rainfall conditions are presented based on the wetting path soil-water characteristic curve in the laboratory. As the field SWCC matches well with the wetting path of the laboratory SWCC from the literatures, it seems reasonable to adopt the laboratory wetting SWCC as an upper boundary condition in the assessment of unsaturated slope instability.

• Journal of the Korean Vacuum Society
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• v.8 no.2
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• pp.158-158
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• 1999

The post ion implantation has been applied to modify early-grown BN layer and improve the adhesion of the BN films. The effect of ion implantation doses on microstructure and interlayer was investigated by FTIR and HRTEM. And the hardness and delamination life time of N+-implanted BN films were measured. With increasing the ion dose up to 5.0×1015atoms/㎠, the change of IR spectrum is observed. At 5.0×1016atoms/㎠, a drastic transition of cubic phase into hexagonal phase is detected. The change of microstructure of early-grown layers by ion implantation is confirmed using HRTEM. Both microhardness and delamination life time of BN films increase with ion dose. The modification model of early-grown BN layers is briefly discussed based on the displacement per atom and excess boron in the BN film induced by ion irradiation.

• Applied Chemistry for Engineering
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• v.10 no.4
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• pp.531-536
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• 1999

Experiments on micro-leak of water were carried out with the water injecting simulator in liquid sodium atmosphere. The leak path was plugged by the sodium-water reaction products in the 2.25Cr-1Mo steel specimen. However, leak paths re-opened in most cases. The self-wastage patterns were not affected by the sodium temperature in the re-opened specimen. The diameter of the defected area, including the re-opened part, was about 5 min. It took 143, 40.7 and 34.7 minutes to re-open the leak path at 450, 475, and $510^{\circ}C$, respectively. It was concluded that the reopening time decreased with the increasing temperature.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2002.05a
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• pp.98-103
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• 2002

BGA(Ball Grid Array) 패키지의 솔더볼 패드 중의 하나인 Au/Ni-Co/Cu 금속층 위에 Bi가 첨가된 Sn-3.5Ag-$\chi$Bi 솔더볼을 리플로우시켰다. 리플로우한 후 130 $^{\circ}C$에서 열처리함에 따른 계면상 및 솔더 내부의 상변화를 관찰하였다. 계면에는 (Ni,Co)$_3$Sn$_4$외에 (Au,Ni,Co,Bi)Sn$_4$가 생성되었음을 관찰할 수 있었고, 솔더 내부에는 (Au,Ni,Co,Bi)SH$_4$, Ag$_3$Sn, Bi 상이 혼재되어 있었다. Nano-indentation에 의한 경도 측정 결과, Bi 함량 증가에 따라 경도는 증가하였으나, 볼전단(Ball Shear) 테스트 결과는 Bi가 증가됨에 따라 오히려 볼전단 강도값이 감소하였다. 이는 파면 검사 결과, 파괴 경로가 주로 계면의 금속간 화합물과 솔더 사이에서 진행함에 기인한 것이다. 솔더 내부의 파괴 경로를 가진 2.5Bi가 가장 우수한 볼전단 강도값을 나타내었는데, 이는 솔더내의 Bi의 고용강화에 기인한 것으로 보인다.

• Journal of IKEEE
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• v.23 no.1
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• pp.280-288
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• 2019

In the CR-enabled MANET, routing paths can be easily destroyed due to node mobility and channel unavailability (due to the emergence of the PU of a channel), resulting in significant overhead to maintain/recover the routing path. In this paper, network caching is actively used for route maintenance, taking into account the properties of the CR. In the proposed scheme, even if a node detects that a path becomes unavailable, it does not generate control messages to establish an alternative path. Instead, the node stores the packets in its local cache and 1) waits for a certain amount of time for the PU to disappear; 2) waits for a little longer while overhearing messages from other flow; 3) after that, the node applies local route recovery process or delay tolerant forwarding strategy. According to the simulation study using the OPNET simulator, it is shown that the proposed scheme successfully reduces the amount of control messages for path recovery and the service latency for the time-sensitive traffic by 13.8% and 45.4%, respectively, compared to the existing scheme. Nevertheless, the delivery ratio of the time-insensitive traffic is improved 14.5% in the proposed scheme.

• The KIPS Transactions:PartC
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• v.14C no.5
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• pp.425-430
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• 2007

Without the aid of stationary infrastructure, maintaining routing information for all nodes is inefficient in the Mobile Ad hoc Networks(MANET). It is more efficient when every time routing information is necessary that the source node broadcasts a query message to neighbour nodes. The source node using Ad hoc On-Demand distance Vector(AODV), which is one of the routing protocols of MANET, uses the Expanding Ring Search(ERS) algorithm which finds a destination node efficiently. In order to reduce the congestion of the network, ERS algorithm does not broadcast Route REQuest(RREQ) messages in the whole network. When the timer expires, if source node does not receive Route REPly(RREP) messages from the destination node, it gradually increases TTL value and broadcasts RREQ messages. Existing AODV cost a great deal to find a destination node because it uses a fixed NODE_TRAVERSAL_TIME value. Without the message which is added in existing AODV protocols, this paper measures delay time among the neighbours' nodes by making use of HELLO messages. We propose Adaptive ERS(AERS) algorithm that makes NET_TRAVERSAL_TIME optimum which apply to the measured delay time to NODE_TRAVERSAL_TIME. AERS suppresses the unnecessary messages, making NET_TRAVERSAL_TIME optimum in this paper. So we will be able to improve a network performance. We prove the effectiveness of the proposed method through simulation.