• Journal of the Korea Computer Graphics Society
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• v.8 no.4
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• pp.9-16
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• 2002

In this paper we propose an extended billboarding method for rendering trees. It's difficult circumstance that PC renders forest by general polygon rendering in real-time, because tree object consists of tremendous leaves and limbs. Our method re-creates an appropriate texture image by 3D image warping equation each frame, and we use it for a billboarding method. For speed up, we use warping method with a image pyramid and image caching.

• International Area Studies Review
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• v.15 no.3
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• pp.429-449
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• 2011

This study investigated the determinants of the foreign direct investment (FDI) by the Korean firms. We focused on types of FDI such as market-seeking, efficiency-seeking, strategic asset-seeking, resource seeking investment and institutional distance including economic distance, political distance and cultural distance which were affecting Korean FDI decision. We tested our hypotheses using Korean FDI data collected between 1980 and 2010. The result showed that Korean FDI to be associated with market-seeking, efficiency-seeking, strategic asset-seeking investment, and institutional distance such as economic distance. We also examined Korean FDI before and after IMF, and the results indicated that before IMF, Korean FDI was associated with market-seeking and strategic asset-seeking investment. However, after IMF, Korean FDI was associated with market-seeking, efficiency-seeking, strategic asset-seeking investment, and institutional distance such as economic distance.

• ETRI Journal
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• v.9 no.2
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• pp.14-23
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• 1987

본고에서는 한국전기통신공사의 출연금으로 연구개발된 565Mbit/s 광전송시스팀의 설계 및 특성을 다루었다. 565Mbit/s 광전송시스팀은 DS3 (44.736 Mbit/s) 및 DS4(139.264 Mbit/s) 신호 를 종속신호로 접속할 수 있으며 중계국에서 종속신호의 드롭 및 인서트가 가능하다. 절체 비율이 최대 11 : 1까지 가능하고, 상세한 시스팀 성능감시가 가능하다. 이때의 유지보수 구간은 국내의 여건을 고려하여 600km로 하였다. 설계 된 광송신 출력은 -3dBm이상,수신감도는 BER 10E-9에서 -37.8dBm, 시스팀 마진을 고려한 최대 중계거리는 27km이었다. 현재 이와같은 성능 및 특성은 범용 IC로 설계되고 구현되어 확인되었다. 그리고 565 Mbit/s 광전송시스팀은 시스팀의 신뢰성 제고 및 경제성을 위하여 주문형 반도체화를 추진하고 있으므로 주문형 반도체화가 끝나면 국내의 장거리 시외국간용이나 대용량 시내국간 중계에 대량으로 사용될 것이 예상된다.

• The Transactions of the Korea Information Processing Society
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• v.3 no.6
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• pp.1636-1645
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• 1996

In this paper we proposed a new scheme for conditional two dimensional (2-D)moment-based classification of patterns on the basis of Gibbs random fields which are will suited for representing spatial continuity that is the characteristic of the most images. This implementation contains two parts: feature extraction and pattern classification. First of all, we extract feature vector which consists of conditional 2-D moments on the basis of estimated Gibbs parameter. Note that the extracted feature vectors are invariant under translation, rotation, size of patterns the corresponding template pattern. In order to evaluate the performance of the proposed scheme, classification experiments with training document sets of characters have been carried out on 486 66Mhz PC. Experiments reveal that the proposed scheme has high classification rate over 94%.

• Journal of Korea Society of Industrial Information Systems
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• v.6 no.2
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• pp.16-22
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• 2001

In this paper we mose a new scheme for recognition of deformed letters by extracting feature vectors based on Gibbs distributions which are well suited for representing the spatial continuity. The extracted feature vectors are comprised of 2-D conditional moments which are invariant under translation, rotation, and scale of an image. The Algorithm for pattern recognition of deformed letters contains two parts: the extraction of feature vector and the recognition process. (i) We extract feature vector which consists of an improved 2-D conditional moments on the basis of estimated conditional Gibbs distribution for an image. (ii) In the recognition phase, the minimization of the discrimination cost function for a deformed letters determines the corresponding template pattern. In order to evaluate the performance of the proposed scheme, recognition experiments with a generated document was conducted. on Workstation. Experiment results reveal that the proposed scheme has high recognition rate over 96%.

• Journal of Korean Society of Transportation
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• v.25 no.4
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• pp.69-77
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• 2007

This study presents comparison results for pedestrian accident reconstruction models representing the relationship between collision speed and horizontal distance that a body travels while falling and sliding. A set of 49 reliable pedestrian accident cases are applied to compare the existing reconstruction models. In addition, the authors investigate the effects of a set of parameters associated with the effects of the frontal shape of a vehicle on the horizontal distance a pedestrian travels while falling and sliding. It has been revealed that the length of the bumper is the most dominant factor to affect the horizontal distance of pedestrian travel after collision. Further analyses utilizing more accident data need to conducted to develop a more accurate and reliable reconstruction model.

• Journal of the Korean Society of Clothing and Textiles
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• v.21 no.1
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• pp.46-57
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• 1997

본 연구의 목적은 두가지 인조섬유 산업, 즉 합성섬유 산업(SITC 266)과 재생섬유 산업(SITC 267)에 있어서, 산업내 무역의 결정요인을 조사하는데 있다. 20개의 주요 인조섬유 수출 국가들을 대상으로 1977, 1982, 1987년의 세 시기에 거힉 자료가 수집되었다. 국제무역 유형을 알아보기 위해 산업내 무역 모델이 사용되었고 종속 변인으로 Grubel-Lloyd지수가 사용되었다. 산업내 무역 을 결정하는 독립변인으로는 국가특성 변인, 국가간 변인, 산업특성 변인의 세 종류가 쓰였다. 국가 특성 변인에는 시장규모, 일인당 소득, 자본-노동 비율 변인들이 사용되었고, 국가간 변인으로는 국가간 거리, 인접국경, 공통언어, 동일 경제블럭 변인들이 사용되었다. 산업특성 변인에는 규모의 경제와 제품차별성 변인들이 쓰였다. 자료의 분석을 위해서는 비선형자승 방법이 이용되었다. 본 연구의 결과, 일인당 소득과 자본-노동의 비율 변인들은 인조섬유의 산업내 무역에 중요하지 않은 것으로 나타났다. 그러나, 시장규모, 국가간 거리, 인접국경, 규모의 경제, 제품차별성 변인들은 모든 시기에 걸켜 산업내 무역에 유의한 영향을 미치는 것으로 나타났다. 또한, 공통언어 사용과 동일 경제블럭 변인들도 대부분의 시기에 인조섬유의 산업내 무역에 유의한 영향을 미치는 것으로 나타났다.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.414-414
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• 2011

우리나라 뿐만 아니라 전 세계적으로 기후변화로 인한 집중호우, 폭설 등이 빈번하게 일어나고 있으며 수공구조물 설계에 필요한 확률강우량도 증가하고 있다. 확률강우량을 산정하는 빈도해석의 경우 지점빈도해석의 문제점을 보완한 지역빈도해석에 대한 연구가 꾸준히 진행되고 있다. 지역빈도해석을 적용하기 위해서는 수문학적 동질성을 가지는 지역 구분이 무엇보다 중요하다. 군집 분석은 개체들이 지니고 있는 다양한 속성의 유사성을 동질적인 집단으로 군집화하는 방법을 말한다. 군집분석의 기본원리는 분석하고자 하는 여러 특성등을 유사성(similaruty) 거리(distance)로 환산하고 거리가 상대적으로 가까운 개체들을 동질적으로 군집화하는 것이다. 군집분석을 적용하기 위해서는 기상학적 인자와 지형학적 인자를 이용하여 군집분석을 실시한다. 군집분석을 실시할 때 가장 중요한 것은 입력변수의 선택으로 입력 변수의 적절한 선택이 결과값에 큰 영향을 준다. 상호정보량(Mutual Information, MI) 기법은 두 무작위 변수간의 관련성을 측정하는 방법이며 (Cover and Tomas, 2006), 두 변수간의 독립성 구조에 관한 가정이 없고 데이터 변형이나 잡음(noise)에 대한 영향이 적어 다른 기법보다 신뢰도가 높다고 알려져 있다(Peng et al., 2005). 본 연구에서는 상호정보량 기법을 이용하여 군집된 지점들의 종속성과 독립성의 관계를 정량적으로 산정하여 비교하고자 한다.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.38 no.5
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• pp.16-26
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• 2001

In this paper, we present a new scheduling method called CDSS(Carried-Dependence Self-Scheduling) for efficiently execution of the loop with intra dependency between iterations based on the central queue. We also implemented it on shared memory system using Java language. Also, we study the modification that converts the existing self-scheduling method based on the central task queue for parallel loops onto the same form applied to loop with loop-carried dependences. The proposed method is self scheduling and assigns the loops in three-level considering the synchronization point according to the dependence distance of the loops. To adapt the proposed scheme and modified methods into various platforms, including a uni-processor system, we use threads for implementation. Compared to other assignment algorithms with various changes of application and system parameters, CDSS is found to be more efficient than other methods in overall execution time including scheduling overheads. CDSS shows improved performance over modified SS, Factoring, GSS and CSS by about 0.02, 40.5, 46.1 and 53.6%, respectively. In CDSS, we achieve the best performance on varying application programs using a few threads, which equal the dependence distance.

• Journal of Korean Society of Forest Science
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• v.85 no.3
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• pp.539-551
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• 1996

In this study, a number of distance-dependent competition indices on tree-level which incorporate the tree sizes and distances to competitors, and traditional stand-level density measures were estimated from the data compiled with position-dependent survey in a Pinus densiflora stand. The performance of the estimated competition indices was examined by comparing the relationship with the diameter growth, and a dbh growth function, in which the competition index is considered as a one of influence factors, are developed. In the searching method of competing trees, the competition index estimated with $30^{\circ}$ competition interrupting angle showed the highest correlation with the annual dbh growth, while the expanding the competing zone distance had no significant effect on the performance of competition index in estimating annual dbh growth. The most of the examined stand-level competition indices, based on distance-dependent single-tree competition indices, were evaluated to describe similarly the stand competition status. As a result of partial correlation analysis in which the effect of age and site index are eliminated, Alemdag's mean competition index and relative spacing index were determined to have the highest correlation with dbh. The relative spacing index, which can be easily measured in field without measuring the position of individual trees, was considered to be a better suited one for estimating mean dbh of a stand. Among distance-dependent competition indices on tree-level, Hegyi's competition index showed the best performance in their correlation with annual dbh growth, if eliminated the effect of site index and dbh. This enabled to derive the following annual dbh growth function of individual trees which incorporate age, dominant height, dbh and Hegyi's competition index as influence factors : $$dbh^{\prime}=3.975362676{\cdot}age^{-1.099274613}{\cdot}ho^{0.199893990}{\cdot}dbh^{0.269430865}{\cdot}HgCI^{-0.353643587}$$ This function is coincided to the growth principle in which site index has a positive effect on the annual dbh growth, while high age or competition causes to reduce the annual dbh growth, and can be used as a function in single tree growth model.