• Journal of the Korean Institute of Navigation
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• v.18 no.4
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• pp.1-9
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• 1994

Assessment of the safety of ship's transit in the narrow channel consist of the maneuvering safety determined by the chance of running aground, the maneuvering difficulty determined by ship's workload and master's subjective evaluation. To examine the relation between master's subjective evaluation and maneuvering safety, this utilizes a real-time and full-mission shiphandling simulator in the Korea Marine Training & Research Institutes(KMTRI). The vessel chosen was 60,000-ton, Panamax-type ship. The findings regarding master's subjective evaluation were as follows: -Relation between master's subjective evaluation and common logarithms of stranding probability is linear. -Stranding probability with more than 0.001 is master's subjective evaluation with more than 5.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.1
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• pp.46-55
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• 2004

Thermal characteristics of the various cooling methods in electronic equipment are studied numerically. A common chip cooling system is modeled as a parallel channel with protruding heat sources. A two-dimensional model has been developed for the numerical analysis of compressible. viscous. laminar flow. and conjugate heat transfer between parallel plates with uniform block heat sources. The finite volume method is used to solve this problem. The assembly consists of two channels formed by two covers and one printed circuit board that is assumed to have three uniform heat source blocks. Various cooling methods are considered to find out the efficient cooling method in a given geometry and heat sources. The velocity and the temperature fields. the local temperature distribution along the surface of blocks. and the maximum temperature in each block are obtained. The results are compared to examine the thermal characteristics of the different cooling methods both quantitatively and qualitatively.

• Asia pacific journal of information systems
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• v.11 no.4
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• pp.27-41
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• 2001

CRM is at the core of any customer-focused business strategy and includes the people, processes, and technology questions associated with marketing, sales, and service. In today's hyper-competitive world, organizations looking to implement successful CRM strategies need to focus on a common view of the customer using integrated information systems and contact center implementations that allow the customer to communicate via any desired communication channel. A CRM solution contains a number of sophisticated tools that enable to extract detailed information about customers. This information can be used to gain a better understanding of customers. From this we can determine trends, and so refine business toward customers' needs and target new products to particular customer groups. This paper presents an approach for forming the product-customer groups using neural networks for customer relationship management. The Carpenter-Grossberg's neural network, which has been used for manufacturing cell formation in group technology, is modified and applied for product-customer group formation. As a result of numerical experiments, it is also useful for more complex problems in which customers have different preferences for each product.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.11a
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• pp.548-550
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• 2013

Multipath routing is proposed to perform better load balancing and to provide high fault tolerance. In this paper common factors on multi-path routing for WMNs are discussed and joint multi-channel and multipath routing approaches for load balancing are introduced at the same time. The key issues on how to design an effective multi-path routing protocol with appropriate performance metrics for WMNs are also discussed through the case studies in the paper.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.6B
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• pp.249-257
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• 2008

Nowadays, client-to-client applications such as online chat (e.g. MSN) and SMS (Short Message Services) are becoming increasingly prevalent. These client-to-client applications are revolutionizing the way we communicate. Three-party PAKE (password authenticated key exchange) protocols provide a means for the two communicating parties holding passwords to establishment a secure channel between them with the help of a common server. In this paper, we propose an efficient three-party PAKE protocol for the client-to-client applications, which has much better performance than the existing generic constructions. We also show that the proposed protocol is secure in a formal security model.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.1
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• pp.60-79
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• 2022

The U-Net architecture-based segmentation models attained remarkable performance in numerous medical image segmentation missions like skin lesion segmentation. Nevertheless, the resolution gradually decreases and the loss of spatial information increases with deeper network. The fusion of adjacent layers is not enough to make up for the lost spatial information, thus resulting in errors of segmentation boundary so as to decline the accuracy of segmentation. To tackle the issue, we propose a new deep learning-based segmentation model. In the decoding stage, the feature channels of each decoding unit are concatenated with all the feature channels of the upper coding unit. Which is done in order to ensure the segmentation effect by integrating spatial and semantic information, and promotes the robustness and generalization of our model by combining the atrous spatial pyramid pooling (ASPP) module and channel attention module (CAM). Extensive experiments on ISIC2016 and ISIC2017 common datasets proved that our model implements well and outperforms compared segmentation models for skin lesion segmentation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.4
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• pp.1296-1309
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• 2023

In this paper, based on the soft cancellation (SCAN) bit-flipping (SCAN-BF) algorithm, a generalized SCAN bit-flipping (GSCAN-BF-Ω) decoding algorithm is carried out, where Ω represents the number of bits flipped or corrected at the same time. GSCAN-BF-Ω algorithm corrects the prior information of the code bits and flips the prior information of the unreliable information bits simultaneously to improve the block error rate (BLER) performance. Then, a joint threshold scheme for the GSCAN-BF-2 decoding algorithm is proposed to reduce the average decoding complexity by considering both the bit channel quality and the reliability of the coded bits. Simulation results show that the GSCAN-BF-Ω decoding algorithm reduces the average decoding latency while getting performance gains compared to the common multiple SCAN bit-flipping decoding algorithm. And the GSCAN-BF-2 decoding algorithm with the joint threshold reduces the average decoding latency further by approximately 50% with only a slight performance loss compared to the GSCAN-BF-2 decoding algorithm.

• Journal of Korea Water Resources Association
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• v.48 no.3
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• pp.169-183
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• 2015

As a basic work for river restoration, analysis on fluvial geomorphological characteristics is made using past and present data to understand close-to-nature geomorphic status. The Miho and the Naesung Rivers are targets of this study. Fluvial geomorphic variables including valley-floor width, sinuosity, bankfull width, channel gradient, bed material size, bankfull discharge and unit stream power are evaluated with dominant processes. Though common sand-bed rivers with similar catchment area, the Miho and the Naesung Rivers are different in terms of valley-floor width, channel shape variables and dominant processes related with longitudinal location. In addition, analyses on interrelationship among the geomorphological variables are carried. Bankfull width is shown to be proportional to bankfull discharge, as is in a rough agreement with the previous studies. Relationship of bankfull discharge and channel gradient shows meandering and braiding are prevalent in the Miho River, whereas the most of the sub-reaches of the Naesung River fall to braiding. Relationship of channel gradient with width-depth ratio indicates dune-ripple processes are dominant in the Miho River, while the Naesung River shows longitudinal diversity from braiding in the downstream sub-reaches to riffle-pool and plane-bed along the upper ones. Analyses based on the past data on a river in a close-to-nature status are thought to be rather reasonable in comparison with those on the same river in a engineered condition.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.421-422
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• 2011

The first part is about development of a liquid target for a neutron source, which is designed to overcome many of the limitations of traditional beam-target neutron generators by utilizing a liquid target neutron source. One of the most critical aspects of the beam-target neutron generator is the target integrity under the beam exposure. A liquid target can be a good solution to overcome damage to the target such as target erosion and depletion of hydrogen isotopes in the active layer, especially for the one operating at high neutron fluxes with no need for water cooling. There is no inherent target lifetime for the liquid target neutron generator when used with continuous refreshment of the target surface exposed to the energetic beam. In this work, liquid target containing hydrogen has been developed and tested in vacuum environment. Potentially, liquid targets could allow a point neutron source whose spatial extension is on the order of 1 to $10{\mu}m$. And the second is about the vacuum ultraviolet (VUV) spectrometer which is designed as a five-channel spectral system for ITER main plasma measurement. To develop and verify the design, a two-channel prototype system was fabricated with No. 3 (14.4 nm~31.8 nm) and No. 4 (29.0 nm~60.0 nm) among the five channels. For test of the prototype system, a hollow cathode lamp is used as a light source. The system is composed of a collimating mirror to collect the light from source to slit, and two holographic diffraction gratings with toroidal geometry to diffract and also to collimate the light from the common slit to detectors. The two gratings are positioned at different optical distances and heights as designed. To study the appropriate detector for ITER VUV system, two different electronic detectors of the back-illuminated charge coupled device and the micro-channel plate electron multiplier were installed and the performance has been investigated and compared in the same experimental conditions. The overall system performance was verified by measuring the spectrums.

• Journal of Ginseng Research
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• v.24 no.4
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• pp.168-175
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• 2000

Relatively little is known about the signaling mechanism of ginseng saponins (ginsenosides), active ingredients of ginseng, in non-neuronal cells. Here, we describe that ginsenosides utilize a common pathway of receptor-mediated signaling pathway in Xenopus oocytes: increase in intracellular $Ca^{2+}$ concentration via phospholipase C (PLC) and $Ca^{2+}$ mobilization. Ginsenosides induced a marked and robust artivation of $Ca^{2+}$-activated Cl- channels in Xenopus oocytes. The effect of ginsenosides was completely reversible, in a dose-dependent manner with EC$_{50}$ of 4.4 $\mu\textrm{g}$/mi, and specifically blocked by niflumic acid, an inhibitor of $Ca^{2+}$-activated Cl- channel. Intracellular injection of BAPIA abolished the effect of ginsenosides. Intracellular injection of GTP${\gamma}$S also abolished the effect of ginsenosides. The effect of gin senosides on $Ca^{2+}$-activated Cl- currents was greatly reduced by the intracellular injection of heparin, an IP$_3$ receptorantagonist or the pretreatment of PLC inhibitor. These results indicate that ginsenosides activate endogenous $Ca^{2+}$-activated Cl- channels via the activation of PLC and the release of $Ca^{2+}$ from the IP$_3$-sensitive intracellular store following the initial interaction with membrane component(s) from extracellular side. This signaling pathway of ginsenosides may be one of the action mechanisms for the pharmacological effects of ginseng.ts of ginseng.