• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.41-47
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• 2007

The selection of the reasonable project delivery system (PDS) is crucial for a successful performance of a project, which means to achieve project objectives. Furthermore, the project performance has been tightly related to the selection of PDS appropriate to pertinent project characteristics. In this context, the ministry of finance and economy of Korea launched two new project delivery systems called "Best Value Contract (Design-Bid-Build)" and "Bridging Contract (Design-Build)" in October of 2007 by revising enforcement ordinances of "Act on Contracts to Which the State is a Party". For efficient operation of the new project delivery systems, this paper suggested a PDS selection model which supports decision making of the reasonable PDS for a pertinent project by assessing characteristics of the public construction projects, both quantitatively and qualitatively. In addition, a PDS performance evaluation model was proposed in order to get feedback on the result of the PDS selection and the operation for the succeeding project. The standard models suggested in this paper might be used as a tool to support the decision making of the public organizations.

• Korean Journal of Construction Engineering and Management
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• v.18 no.5
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• pp.50-58
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• 2017

The efficient communication process is essential to guarantee the completeness of design and secure the quality to meet the contractor's needs. However, using the existing communication methods based on the design and documents, it is difficult to effectively understand the drawings and specifications that are very complicated, and sufficient technical experiences would be required. Ineffective and inefficient communication among users, designers and project participants during the design process would raise the possibility of functional interferences of the object, induce conflicts, cause a design change, and accordingly incur losses of the project in terms of cost and time. The purpose of this study is to suggest improvement direction of communication in accordance with the requirements, by investigating the present state and the project participants' understanding of design communication. And also, it presents the application model of QFD that the project participants could share and define, and feedback the requirements as well as conducting analysis of improvement factors based on the survey.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.315-318
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• 2005

Recently, the advent of wireless communication and other handhold devices like Personal Digital Assistants and smart cards have made in implementation of cryptosystems a major issue. One important aspect of modern day ciphers is the scope for hardware sharing between the encryption and decryption algorithm. The cellular Automata which have been proposed as an alternative to linear feedback shift registers(LFSRs) can be programmed to perform the operations without using any dedicated hardware. But to generalize and analyze CA is not easy. In this paper, we characterizes uniform/hybird complemented group CA with rules 195/153/51 that divide the entire state space into smaller spaces of maximal equal lengths. This properties can be useful in constructing key agreement algorithm.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.2A
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• pp.170-176
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• 2009

It has been known that multiuser MIMO systems have better performance than single-user MIMO systems. However, multiuser MIMO systems should eliminate inter-user interferences which are generated by allocating data to multiple users simultaneously There is zero-forcing beamforming (ZFBF) as scheme used widely among algorithms to eliminate inter-user interferences. But, it needs many feedback bits since BS knows quite exact channel state information to use this scheme in real systems. Random beamforming (RBF) was proposed to cope with a defect of ZFBF[1]. RBF is a multiuser scheme to send data to users who have optimal performance with predetermined codebook, each receiver feeds back a index of codeword which has optimal performance within the codebook and its CQI information. [1] assumes that the BS knows perfect CQI information of each receiver but CQI information should be quantized in the real systems. Therefore, in this paper, efficient CQI quantization scheme for RBF system is proposed.

• The Transactions of the Korean Institute of Power Electronics
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• v.16 no.4
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• pp.309-316
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• 2011

A PLL system has widely used for synchronizing the grid voltage at the grid-connected inverter for supplying power from the PV generation systems. In this paper, a PLL algorithm without both the loop filter and PI controller is suggested for improving the performance of synchronization at the single-phase and three-phase grid connected inverters. In order that the output voltage of a phase detector in the PLL has only a dc voltage, and it approaches to 0 when the synchronization signal is locked to the grid voltage, the feedback signals are determined by using two-phase voltages. After the PLL system with a proportional controller is modelled with the small signal analysis, the stability and steady-state error are investigated. Through the simulation studies and experimental results, the performances of the proposed PLL algorithm are verified.

• The Korean Journal of Physiology and Pharmacology
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• v.24 no.6
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• pp.517-527
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• 2020

Layer 2/3 pyramidal neurons (L2/3 PyNs) of the cortex extend their basal dendrites near the soma and as apical dendritic tufts in layer 1, which mainly receive feedforward and feedback inputs, respectively. It is suggested that neuromodulators such as serotonin and acetylcholine may regulate the information flow between brain structures depending on the brain state. However, little is known about the dendritic compartment-specific induction of synaptic transmission in single PyNs. Here, we studied layer-specific serotonergic and cholinergic induction of long-term synaptic plasticity in L2/3 PyNs of the agranular insular cortex, a lateral component of the orbitofrontal cortex. Using FM1-43 dye unloading, we verified that local electrical stimulation to layers 1 (L1) and 3 (L3) activated axon terminals mostly located in L1 and perisomatic area (L2/3). Independent and AMPA receptor-mediated excitatory postsynaptic potential was evoked by local electrical stimulation of either L1 or L3. Application of serotonin (5-HT, 10 μM) induced activity-dependent longterm depression (LTD) in L2/3 but not in L1 inputs. LTD induced by 5-HT was blocked by the 5-HT₂ receptor antagonist ketanserin, an NMDA receptor antagonist and by intracellular Ca²⁺ chelation. The 5-HT₂ receptor agonist α-me-5-HT mimicked the LTD induced by 5-HT. However, the application of carbachol induced muscarinic receptor-dependent LTD in both inputs. The differential layer-specific induction of LTD by neuromodulators might play an important role in information processing mechanism of the prefrontal cortex.

• Journal of Satellite, Information and Communications
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• v.7 no.1
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• pp.65-74
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• 2012

The QoS guarantee for the forward link in satellite communication networks is very important because there are a variety of packets with multiplexing. Especially, the packets are processed depending on the available bandwidth in satellite network changing the wireless channel state in accordance with weather condition. The DVB-S2 increases the transmission efficiency by applying the adaptive coding and modulation (ACM) techniques as a countermeasure of rain attenuations. However, the channel estimation algorithm is required to support the ACM techniques that select the MODCOD values depending on the feedback data transmitted by RCSTs(Return Channel via Satellite Terminal) because satellite communication networks have a long propagation delay. In this paper, we proposed the channel estimation algorithm using rain attenuation values and reference data and the packet scheduling scheme to support the QoS and fairness. As a result of performance evaluation, we showed that proposed algorithm exactly predicts the channel conditions and supports bandwidth fairness to the individual RCST and guarantees QoS for user traffics.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.12
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• pp.2812-2817
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• 2013

In this paper, an outage probability for the best relay selection in decode-and-forward relaying systems in the presence of interference is analyzed over Rayleigh fading channels. Based on the outage performance results, we propose a method to determine effective relay candidates for the best relay selection, where the effective relay candidates represent the relays except for relays that make no contribution to improving the performance. in all possible relays given in the system. By determining the effective relay candidates, the feedback overhead of channel state information and the energy consumption of relays can be significantly reduced while minimizing the performance degradation. In this paper, we provide important parameters that affect the determination of the effective relay candidates.

• KIPS Transactions on Software and Data Engineering
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• v.5 no.6
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• pp.289-294
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• 2016

In recent times, as most people develop keen interest in health management, the importance of cultivating dietary habits to prevent various chronic diseases is emphasized. Subsequently, dietary management systems using a variety of mobile and web application interfaces have emerged. However, these systems are difficult to apply in real world and also do not provide personalized information reflective of the user's situation. Hence it is necessary to develop a personalized dietary management and recommendation method that considers user's body state information, food analysis and other essential statistics. In this paper, we analyze nutrition using self-organizing map (SOM) and prepare data about nutrition using clustering. We provide a substitute food recommendation method and also give feedback about the food that user wants to eat based on personalized criteria. The experiment results show that the distance between input food and recommended food of the proposed method is short compared to the recommended food results using general methods and proved that nutritional similar food is recommended.

• Korean Journal of Comparative Education
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• v.28 no.2
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• pp.77-95
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• 2018

This study introduces the Classroom Assessment Scoring System (CLASS) and explores the characteristics of CLASS for observing classroom. The CLASS is a standardized observation instrument that was largely developed for use in the USA. The CLASS attempts to provide a conceptual framework for categorizing classroom interactions and consists of three broad domains of quality (emotional supports, classroom organization, instructional supports). We simulated this method to the elementary school classes. The professional-teacher makes the best use of student's initiation behaviors, and the novice teacher focused on the leading the contents of subject. The novice teacher tyr to make more positive climate and to present more frequent feedback to students than professional teacher's classroom. The professional teacher would like to reveal the student's opinions, questions and subtle emotional state. The CLASS can be used to collect data on a wide range of specific aspects of the teaching and learning process at any given time.