• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.1
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• pp.22-27
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• 1992

This study was conducted to select an excellent goods and to estabilish the plant density of Amorphohpallus konjac. K about 3 local varieties and 2 introduced varieties through each fertilizer level. 1. Plant height and leaf width were increased according to increasing fertilizer level, and tuber yield was the highest at N-P$_2$ $O_{5}$ -K$_2$ O (14-10-14kg) per 10a as 390kg in Geumsan. 2. The more tuber size was large, the more yields per plant due to increasing the plant height and leaf width at low densities, while yields per 10a was decreased. 3. Among 5 varieties used, Jechon cultivar was good as a propagating variety because of increasing number of tuber and bulblet and Japan cultivar was high tuber yield per 10a.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.6 no.2
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• pp.34-44
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• 2007

Many urban cities deployed ITS technologies to improve the efficiency of traffic operation and management including a real-time franc control system (i.e., COSMOS). The system adopted loop detector system to collect traffic information such as volume, occupancy time, degree of saturation, and queue length. This paper investigated the applicability of detector information within COSMOS to represent the congestion level of the links. Initially, link travel times obtained from the field study were related with each of detector information. Results showed that queue length was highly correlated with link travel time, and direct link travel time estimation using the spot speed data produced high estimation error rates. From this analysis, a procedure was proposed to estimate congestion level of the links using both degree of saturation and queue length information.

• The Journal of the Korea Contents Association
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• v.13 no.12
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• pp.9-18
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• 2013

In recent years, the demands of multimedia data in wireless sensor networks have been significantly increased for the high-quality environment monitoring applications that utilize sensor nodes to collect multimedia data. However, since the amount of multimedia data is very large, the network lifetime and network performance are significantly reduced due to excessive energy consumption on particular nodes. In this paper, we propose an energy-efficient dynamic area compression scheme in wireless multimedia sensor networks. The proposed scheme minimizes the energy consumption in the huge multimedia data transmission process by compression using the Chinese Remainder Theorem(CRT) and dynamic area detection and division algorithm. Our experimental results show that our proposed scheme improves the data compression ratio by about 37% and reduces the amount of transmitted data by about 56% over the existing scheme on average. In addition, the proposed scheme increases network lifetime by about 14% over the existing scheme on average.

• Annual Conference on Human and Language Technology
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• 2017.10a
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• pp.288-293
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• 2017

교수-학습 발화는 발화 턴 간에 규칙화된 인과관계가 강하고 자연 발화에서의 출현율이 낮다. 일반적으로 어휘부, 표현 제시부, 대화부로 구성되며 커리큘럼과 화제에 따라 구축된 언어자원이 필요하다. 기존의 말뭉치는 이러한 교수-학습 발화의 특징을 반영하지 않았기 때문에 한국어 교육용 튜터링 챗봇을 개발하는데에 활용도가 떨어진다. 이에 따라 이 논문에서는 자연스러운 언어 사용 수집, 도구 기반의 수집, 주제별 수집 및 분류, 점진적 구축 절차의 원칙에 따라 교수-학습의 실제 상황을 반영하는 준구어 말뭉치를 구축한다. 교실에서 발생하는 언어학습 상황을 시나리오로 구성하여 대화 흐름을 제어하고 채팅용 메신저와 유사한 형태의 도구를 통해 말뭉치를 구축한다. 이 연구는 한국어 튜터링 챗봇을 개발하기 위해 말뭉치 구축용 챗봇과 한국어 학습자, 한국어 교수자가 시나리오를 기반으로 발화문을 생성한 준구어 말뭉치를 최초로 구축한다는 데에 의의가 있다.

• Journal of Korea Multimedia Society
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• v.12 no.7
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• pp.962-970
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• 2009

This paper presents a data gathering and scheduling scheme for wireless sensor networks. We use a data gathering tree for sending the data from the sensor node to the base station. For an energy efficient operation of the sensor networks in a distributed manner, a time tree is built in order to reduce the collision probability and to minimize the total energy required to send data to the base station. A time tree is a data gathering tree where the base station is the root and each sensor node is either a relaying or a leaf node of the tree. Each tree operates in a different time schedule with possible different activation rate. Through the simulation, we found that the proposed scheme that uses time trees shows better characteristics in energy and data arrival rate when compared with other schemes such as SMAC and DMAC.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.5
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• pp.1234-1241
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• 2008

Cost effectiveness is greatly related with the degree of reducing the testing cost by the technical reviews. In this paper, we present a new metric My for evaluating the cost effectiveness of technical reviews during software development. First, we estimate and compare My with conventional measure using data collected during practical software development procedure, then we show the validity and usefulness of the proposed measure My. Also by formulating the relationship between the data collected during the reviews and the test, we present a method to estimate the value of the metric My using only the data collected during review phase.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.1
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• pp.92-97
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• 2012

This paper suggests a data gathering scheme using dynamic branch tree in wireless sensor networks. A mobile sink gathers data from each sensor node using a dynamic data gathering tree rooted at the mobile sink node. As the sink moves, a tree that has multiple branch is formed and changed dynamically as with the position of the sink node. A hop-based scope filter and a restricted flooding scheme of the tree are also suggested. Simulation results show that the proposed data gathering scheme has better results in data arrival rate, the end-to-end delay and energy saving characteristics compared with the previous scheme.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.580-581
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• 2018

In order to reduce end-to-end delay in EH-WSN (energy harvestin wireless sensor netowk), medium access control protocols using multi-hop routing technique have been studied. In a real environment, there are many situations where it is difficult to harvest enough energy than the energy consumed. Therefore, it is required to design a MAC protocol that allows nodes to reliably relay data without exhausting power in multi-hop transmission. In this paper, we propose a power-efficient MAC protocol that can select the relay node according to the residual power and the energy collection rate to increase network lifetime.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.4
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• pp.53-58
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• 2012

The roadside unit (RSU) collects vehicle information from vehicles in the intelligent transportation system (ITS). The vehicle density on the road within the communication range of a RSU is a time varying parameter. The higher the vehicle density, the more vehicle information can be collected. Therefore, the probability of packet collision will be raised. In this paper, an adaptive transmission scheme is proposed to improve the probability of packet reception rate by changing the data rate and transmission period according to the vehicle density. The performance of IEEE 802.11p MAC protocol that is a standard for vehicular communications is evaulated in terms of the vehicle density with the ns-2,33 simulator.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.744-744
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• 2012

불투수층은 자연적인 침투를 허용하지 않는 인위적인 토지피복상태로 도시화율 추정 및 유역의 환경변화 정도를 분석하기 위한 척도로 사용되어 왔다. 특히, 수문학적 관점에서 불투수층은 단기 유출현상에 큰 영향을 끼치는 요소로 불투수율이 증가할수록 침투량이 감소하여 첨두유출량은 증가하고 도달시간은 짧아진다. 최근에는 급속한 도시화로 인해 불투수층의 영향이 더욱 커짐에 따라 불투수율의 추정에 대한 필요성이 증가하고 있다. 현재까지 위성영상을 이용한 불투수층의 추정은 고해상도 영상을 이용하여 피복분류를 수행하였다. 즉, 분류된 토지피복에 근거하여 불투수율을 산술적으로 계산하거나 분광혼합기법 및 회귀 트리기법 등 다양한 방법에 적용되어 왔다. 본 연구에서는 Sub-pixel 분류기법을 위성영상에 적용하여 섬강유역의 불투수율을 추정하고자 한다. Sub-pixel 분류는 기존 분류기법들이 다양한 토지피복이 혼합된 화소에 대해서도 가장 비중이 높은 토지피복 하나로 분류하던 것을 개선한 방법으로 fuzzy 이론을 적용하여 최소 20% 이상의 비율을 점유하는 항목 모두를 구분하여 분류하는 기법이다. 이를 위해 섬강유역의 Landsat TM 영상을 수집하고 환경부의 토지피복도와 지질도를 참조하여 트레이닝 자료를 수집하였다. 또한 결과에 영향을 미칠 수 있는 구름은 전처리를 통하여 제거하고 수집된 트레이닝 자료에 Sub-pixel 분류기법을 적용하여 섬강유역의 불투수율을 공간분포도로 작성하였다.