• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.4
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• pp.440-448
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• 1989

The present experiment was conducted to investigate the effects of seeding date on agronomic characters including seed weight of soybean (Glycine max (L.) Merr.) at Sunchon, the southern coastal area of Korea. One hundred eighteen native and improved varieties were used in this study. As the seeding date was delayed, the number of days to flowering for the cultivars was reduced. This trend was more obvious in late maturing cultivars(LMC) than in early and medium maturing cultivars (EMC and MMC). Late seeding also resulted in decrease in the number of leaves, stem length, and number of nodes. The heaviest seed weight was obtained with EMC and MMC planted on May, and seed weight decreased with delayed seeding date. Seed weight was positively correlated with number of days to flowering, number of total leaves at flowering, stem length and number of nodes on main stem at maturity. Based on seed weight the cultivars was classified into five types: Type I; Seed weight of the cultivars decreases with delayed seeding date. Type II; Seed weight of the cultivars does not vary with seeding date. Tyep III; Seed weight of the cultivars increases with delayed seeding date. Type IV; Seed weight of the cultivars increases when the seeding date approached the appropriate seeding date, but decreases thereafter. Type V; The reversed type IV. Type I, II, III, IV and V occupied 37, 16, 17, 10 and 20％ of the tested cultivars, respectively.

• Proceedings of the Korean Information Science Society Conference
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• 2008.06d
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• pp.255-258
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• 2008

현재 이동통신 네트워크는 통신 기술의 발전에 힘입어 음성 서비스를 넘어선 다양한 패킷 데이터 기반 서비스를 제공하고 있다. 하지만 현재 IEEE 802.11과 같은 이기종 네트워크에 대한 연구가 다양하게 진행되고 있는 것과 달리 이동통신 네트워크의 패킷 데이터 기반 서비스에 대한 연구는 이루어지지 않았다. 이러한 추세의 원인은 이동통신 네트워크가 사업자에 의해서 폐쇄적으로 운영되고 있기 때문이다. 우리는 지금까지 이기종 네트워크에 대한 연구를 바탕으로 예측만 하던 문제를 해결하기 위해 이 논문은 통해서 이동통신 네트워크의 패킷 기반 데이터 서비스의 특징을 분석한다. 실제 트래픽을 모두 분석하는 것은 규모의 문제로 불가능했기 때문에 우리는 서비스에 대한 과금 데이터를 사용했다. 과금 데이터에는 네트워크의 특징이 대부분 반영되어 있기 때문에 실제 트래픽을 수집해서 분석하는 것과 같다. 분석결 과로 이동통신 환경에서 사용자 행동 패턴과 서비스 유형별 트래픽 특성 및 네트워크의 특징을 보여준다. 이러한 결과는 향후 네트워크 진화에 의해서 예상되는 트래픽 예측 및 관리에 활용 가능하고, 네트 워크 모델링에 있어서의 기반 지식을 제공한다.

• Journal of Labour Economics
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• v.31 no.1
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• pp.29-57
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• 2008

We construct a unique panel data by using Korean Economically Active Population Survey (KEAPS) from 2003 to 2007 to estimate the returns to different types of job mobility among men. By adopting Mincer(1986)'s method, we estimate the wage change to job mobility after controlling the sample selection bias. There are four different types of job mobility that are concerned in the study: (1) voluntary job-to-job changes without experiencing unemployment, (2) voluntary job changes with experiencing unemployment, (3) involuntary job changes due to layoffs, and (4) involuntary job changes due to discharges. Our findings indicate that Korean men who changed jobs without experiencing unemployment realized wage gains of 7% while those who changed jobs through unemployment period lost 10% of their wages. Among those who changed jobs involuntarily and went through unemployment, the workers who discharged from the previous jobs realized substantially greater wage loss.

• Journal of the Korean association of regional geographers
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• v.18 no.3
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• pp.253-267
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• 2012

The study looked into the type and characteristics of debris landforms in Mt. Mudeung. By focusing on the representative area, we aimed to categorize the debris landforms based on the morphologic and genetic characteristcis. The types of debris areas in Mt. Mudeung can be divided into the exposed debris type, mixed type of matrix, and the boulder-hidden type. Supply of block in the debris slope area displays different features depending on types of rocks. For the stony slopes of andesite, the block must be moved from the columnar joint or cliff in the upper part. The andesite debris slopes display dominant edge shape while displaying no round shape. The granite stony slopes display dominant round shape and the present exposed slope was assumed to be formed as the core stone which was deep weathered moved along slope during the periglacial era and the matrix was removed after post-glacial era. The movements of blocks are assumed to be caused by solifluction process. The joint area where granite and andesite areas meet, granite is located beneath andesite area, and this implies that blocks were actively freezing and creeping by solifluction and freezing and thawing at that time. It can be assumes that the granite matrix formed plain slope and then andesite boulder covered up the slope. Currently, the blocks in the stony slopes of Mt. Mudeung shows almost no mobility and the stony slopes created under periglacial climate can be considered to be fossil landform.

• 재활복지
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• v.20 no.3
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• pp.83-104
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• 2016

The purpose of this study was to identify improvement in locomotor skills by physical activity programs. Method of this study indicates that the current literature (2004-2015) were reviewed and the data from 24 studies with 518 disabled children were analyzed by using CMA3 (Comprehensive Meta-Analysis ver.3) program. Analyzing the data of the primary studies included gender, age, type of disabilities, duration of the physical activity program intervention(weeks, session per week, minutes per session), run, gallop, hop, leap, horizontal jump, and slide. For sensitivity analysis, publication bias and outlier were reviewed. Results of analysis indicates that the overall effect size of improvement in locomotor skills by physical activity programs was 1.143. There were large effect size in categorical analyses. Autistic spectrum among type of disabilities was 1.697 and run among 6 of locomotor skills was 1.019. 8~10 aged was 0.920 and the intervention of 100~120minutes(1.261)per session, 3sessions(1.078) per week, 16~20(1.587)weeks was found to be more larger than the others. In conclusion, improvement in locomotor skills by program participation showed that treated group was 37% more effective than control group.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.31 no.2
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• pp.50-61
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• 2019

The aspects of typhoon-induced surges were classified into three types at the Western coast, and their characteristics were examined. The typhoons OLGA (9907) and KOMPASU (1007) were the representative steep types. As they pass close to the coasts with fast translation velocity, the time of maximum surge is unrelated to tidal phase. However, typhoons PRAPIROON (0012) and BOLAVEN (1215) were the representative mild types, which pass at a long distance to the coasts with slow translation velocity, and were characterized by having maximum surge time is near low tide. Meanwhile, typhoons MUIFA (1109) and WINNIE (9713) can be classified into mild types, but they do not show the characteristics of the mild type. Thus they are classified into propagative type, which are propagated from the outside. Analyzing the annual highest high water level data, the highest water level ever had been recorded when the WINNIE (9713) had attacked. At that time, severe astronomical tide condition overlapped modest surge. Therefore, if severe astronomical tide encounter severe surge in the future, tremendous water level may be formed with very small probability. However, considering that most of the huge typhoons are mild type, time of maximum surge tends to occur at low tide. In case of estimating the extreme water level by a numerical simulation, it is necessary not only to apply various tide conditions and accompanying tide-modulated surge, but also to scrutinize typhoon parameters such as translation velocity and so on.

• Journal of Advanced Navigation Technology
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• v.6 no.1
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• pp.1-9
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• 2002

본 논문은 현재 무선 LAN 환경에서 적용되고 있는 매체접근제어 프로토콜인 IEEE 802.11 CSMA/CA를 이용함으로써, 음성 위주의 항공이동통신에서 음성과 데이터 채널을 통합하여 사용하도록 하고 있다. 또한, 표준으로 제정되어 있는 기존의 CSMA/CA 매체접근제어 프로토콜에 대한 이해를 바탕으로 성능 개선 방안을 제안하였으며, 이를 바탕으로 채널 효율을 향상시켰다. IEEE 802.11 매체접근제어(MAC, Medium Access Control) 프로토콜은 데이터 유형에 따라 채널을 두 개의 구간(PCF와 DCF 구간)으로 나누어 전송하도록 하고 있다. 본 논문에서는, 데이터 유형별로 적용되는 구간 중, DCF 구간에서의 패킷간의 충돌 가능성을 줄임으로써 데이터 전송 효율을 높이는데 주안점을 두고 있다. 제안 방안으로는 경쟁 구간에서의 전송에서 충돌에 따른 손실을 보완할 수 있도록 Wireless Window Protocol(이하, WWP)을 적용한 후 전송 과정을 제어하였다. Hidden 터미널의 영향이 적으므로 가시권내 통신에 적합한 기존의 2-Way CSMA/CA 프로토콜을 항공통신에 적용하여 상태 천이 과정을 5개에서 6개로 세분화하였고, 주어진 확률에 의하여 나누어진 두 개의 그룹별로 상태 천이 과정을 다르게 적용하였다. 따라서, 채널이 한 항공기에 의해 점유되는 PCF를 제외한, DCF 구간에서의 데이터 전송 효율을 높일 수 있었다. 시뮬레이션은 채널 대역폭과 패킷 크기 등을 파라미터 값으로 하여 수행하였으며, 시뮬레이션 결과 CSMA/CA에 비해 새로 제안한 알고리즘이 데이터 전송 과정에서 발생하는 충돌 가능성을 감소시킴으로써 성능이 향상됨을 알 수 있었다.

• The Journal of the Korea Contents Association
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• v.9 no.11
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• pp.335-347
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• 2009

This research analyzes the use intention of the ubiquitous service based on the technology acceptance model (TAM). This study investigates the characteristics of the ubiquitous service like the ubiquity, personality, connectivity, and location. The major results of this study are as follows. The ubiquity, connectivity, and location had positive influences on the perceived usefulness and perceived ease of use. And, the personality had the positive influence of the perceived ease of use. The perceived usefulness and perceived ease of use had the positive effect to an attitude, and the attitude had the positive effect to an use intention. When it consider the market share or the growth potential of the wireless internet service industry, this research results will be able to tilize as the basic information of an industry.

• Korean Journal of Cognitive Science
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• v.9 no.1
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• pp.41-46
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• 1998

The argument-structure distributions of predicates in the speech of two roca-type aphasic patients and one Conduction-type patient are compared with both matched controls and each other on the basis of narrative production data. Whereas English-speaking agrammatics have been reported to have difficulties producing noncopular unaccusative predicates (Kegl 1995) Korean-speaking agrammatics are found not to have particular difficulties with unaccusative predicates. On the assumption that agrammatics lack specific syntactic knowledge for the processing of displaced arguments from their lexically specified positions. it is proposed that unaccusatives in Korean do not involve the displacement of arguments for Case-theoretic reasons or involve a vacuous movement. if any.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.04a
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• pp.25-27
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• 2016

본 논문은 카메라와 적외선 센서를 이용하여 수직 벽면을 이동하는 로봇에 최적화 된 장애물 인식방법을 제안한다. 장애물을 인식 하는 순서는 적외선 센서를 통해 앞에 장애물이 있는지 확인하고 카메라를 이용하여 앞의 장애물의 유형을 판단한다. 장애물의 유형은 크게 작은 장애물과 직선 장애물 그리고 곡선 장애물이 있다. 곡선 장애물과 작은 장애물의 경우에는 회피를 하고 직선 장애물인 경우 장애물을 넘어간다. 장애물과 로봇은 수평으로 맞추어야 안정적으로 장애물을 건널 수 있으므로 넘어가야 하는 장애물이라면 수평인지 판단하고 수평이 아니라면 회전을 통해서 수평을 맞춘다. 수평이 맞추어 지면 장애물을 넘어간다.