• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제54권9호
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• pp.403-407
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• 2005

Most of the loads in industrial power distribution systems are balanced and connected to three power systems. However, voltage unbalance is generated at the user's 3-phase 4-wire distribution systems with single & three phase. Voltage unbalance is mainly affected by load system rather than power system. Unbalanced voltage will draws a highly unbalanced current and results in the temperature rise and the low output characteristics at the machine. It is necessary to analyse correct voltage unbalance factor for reduction of side effects in the industrial sites. Voltage unbalance is usually defined by the maximum percent deviation of voltages from their average value, by the method of symmetric components or by the expression in a more user-friendly form which requires only the three line voltage readings. If the neutral point is moved by the unbalanced load at the 3-phase 4-wire system. Line and phase voltage unbalance leads to different results due to zero-sequence component. So that it is difficult to analyse voltage unbalance factor by the conventional analytical method, This paper presents a new analytical method for phase and line voltage unbalance factor in 4-wire systems. Two methods indicate exact results.

• 한국정보통신학회논문지
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• 제11권6호
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• pp.1122-1128
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• 2007

본 논문은 웨이블릿 패킷 변환과 AA(절대평균)임계값 설정 기반에 의한 영상의 노이즈를 제거하여 영상을 복원하는 연구이다. 웨이블릿 패킷 변환은 웨이블릿 변환보다 고주파부분에서 노이즈 제거가 효과적이다. 또한 기존에 사용된 임계값 결정은 표준편차 추정치를 사용하므로 노이즈 크기가 커지면 임계값이 증가하고 영상도 손상되고, 노이즈 크기에 비례하여 임계값이 설정되므로 영상이 변해도 동일한 임계값이 적용되어 복원 영상의 PSNR이 저하된다. 반면 AA임계값 적용기법은 극단적인 영향을 피할 수 있고 분해된 영상의 통계량에 따라 임계값이 결정되므로 영상의 변화에 적응적이다. 실험 결과 표준편차 추정 임계값을 적용한 웨이블릿 변환기법과 비교하여 10%, 웨이블릿 패킷 기반 노이즈 제거기법과는 5% PSNR이 증가하였다.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2005년도 춘계학술대회논문집
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• pp.74-77
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• 2005

Most of the loads in industrial power distribution systems are balanced and connected to three power systems. However, voltage unbalance is generated at the user's 3-phase 4-wire distribution systems with single & three phase. Voltage unbalance is mainly affected by load system rather than power system. Unbalanced voltage will draws a highly unbalanced current and results in the temperature rise and the low output characteristics at the machine. It is necessary to analyse correct voltage unbalance factor for reduction of side effects in the industrial sites. Voltage unbalance is usually defined by the maximum percent deviation of voltages from their average value, by the method of symmetrical components or by the expression in a more user-friendly form which requires only the three line voltage readings. If the neutral point is moved at the 3-phase 4-wire system by the unbalanced load, by the conventional analytical method, line and phase voltage unbalance leads to different results due to zero-sequence component. This paper presents a new analytical method for phase and line voltage unbalance factor in 4-wire systems. Two methods indicate exact results.

• 로봇학회논문지
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• 제18권4호
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• pp.487-495
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• 2023

This paper presents a method for autonomous exploration of indoor environments using a 2-dimensional Light Detection And Ranging (LiDAR) scanner. The proposed frontier-based exploration method considers navigability from the current robot position to extracted frontier targets. An approach to constructing the point cloud grid map that accurately reflects the occupancy probability of glass obstacles is proposed, enabling identification of safe frontier grids on the safety grid map calculated from the point cloud grid map. Navigability, indicating whether the robot can successfully navigate to each frontier target, is calculated by applying the skeletonization-informed rapidly exploring random tree algorithm to the safety grid map. While conventional exploration approaches have focused on frontier detection and target position/direction decision, the proposed method discusses a safe navigation approach for the overall exploration process until the completion of mapping. Real-world experiments have been conducted to verify that the proposed method leads the robot to avoid glass obstacles and safely navigate the entire environment, constructing the point cloud map and calculating the navigability with low computing time deviation.

• 암석학회지
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• 제14권3호
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• pp.141-148
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• 2005

연화, 장군 및 울진 Pb-Zn 광상에서 산출되는 납의 근원을 규명하기 위하여 방연석과 황철석 등의 황화광물과 주변의 석회암, 관입암 및 기반암 등에 대해 납 동위원소 분석을 실시하였다. $^{206}Pb/^{204}Pb-^{207}Pb/^{204}Pb$ 그림에서 연화광산의 방연석들은 비교적 잘 정의되는 정(+)의 기울기를 갖는 직선 배열을 보이며, 한반도 선캠브리아 기저지각과 유사한 변화를 보인다. 울진광산의 방연석, 장군석회암 및 주변의 기저암체 역시 연화광산의 변화경향을 따른다. 그러나 연화광산에 비해 $^{206}Pb/^{204}Pb$값이 낮은 장군광산의 광석광물들은 연화광산의 변화경향으로부터 $^{207}Pb/^{204}Pb$ 값이 낮은 쪽으로 벗어난다. 경상분지 내에서 산출되는 중생대 화성암 및 광상들이 한반도의 기저암체들에 비해 훨씬 낮은 $^{207}Pb/^{204}Pb$ 값을 가지는 것을 참조할 때, 장군광산의 광석광물들이 보이는 변화는 기저암체의 오래된 지각물질로부터 용출된 납과 중생대 화성암들이 갖고 있던 보다 맨틀성분이 많이 포함된 납의 혼합을 반영하는 것으로 해석된다. 선캠브리아 기저지각의 변화경향을 비교적 잘 따르는 연화광산과 울진광산의 광석들에 포함된 납은 대부분 오래된 기저암체들로부터 유래한 것으로 보이나, 기저암체의 변화구역의 하단부에 위치하는 것을 고려할 때 중성대 화성암 기원의 납이 일정비율로 포함되었을 가능성을 배제할 수 없다.

• 대한교통학회지
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• 제30권3호
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• pp.31-41
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• 2012

VMS, 교통방송(라디오), SNS 등 교통정보제공을 통한 교통량 분산에 대한 관심이 높아짐에 따라 교통정보에 대한 운전자의 반응행태 및 효과에 대한 연구가 지속적으로 이루어지고 있다. 본 연구는 FTMS 및 TCS 데이터가 구축되어 있는 전국 고속도로 본선부를 분석 대상으로, FTMS 데이터와 TCS 데이터를 이용하여 경로전환 교통량과 그에 따른 경로전환율을 추정하는 방법론을 제시하고, 실제 대상구간의 경로전환율을 산출하여 시간 및 공간적 경로 전환율 변동에 대한 특성을 분석하였다. 본 연구에서는 교통정보 제공 이후, 해당 시간대의 평균 유출교통량에 비해 유출교통량이 일시적으로 증가한 경우 이 편차(도로교통상황의 동적인 특성으로 인한 편차 고려)는 교통정보 제공으로 인한 경로전환 교통량이라 정의하고, 본선 교통량과의 비율을 경로전환율로 계산하였다. 시간흐름에 따른 경로전환율 변화를 분석한 결과, 혼잡상황에 대한 교통정보를 먼저 얻게 되는 상류부 IC에서의 초기 경로전환율(유출교통량) 변화는 일시적으로 매우 큰 것으로 나타났다. 이후 공간적 시간적 흐름에 따라 상류부 IC에서의 경로전환율의 변화는 하류부 IC에서의 경로전환에 영향을 미치고, 이는 다시 상류부 IC에서의 변화를 유도하는 등의 경로전환 순환체계(feedback control loop)가 있음을 확인하였다.

• 대한소아치과학회지
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• 제42권1호
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• pp.87-101
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• 2015

하악 유견치의 조기탈락은 임상에서 흔히 관찰되는 현상으로 후에 영구치열에서 총생의 징후라 할 수 있으며 향후 영구 전치의 배열상의 문제점이나 부정교합을 유발할 수 있다. 영구 측절치가 맹출될 때 맹출 공간이 부족할 경우 인접해 있는 유견치 치근을 흡수시키면서 맹출하게 되고 그 결과 유견치가 조기에 탈락하게 되는데, 이 경우 영구 하악 영구 절치들이 설측으로 경사지게 되면 상악 절치들과 교합 접촉이 상실되어 상악 절치들이 과맹출됨으로써 수직피개교합 및 수평피개교합이 깊어지며 악궁둘레길이는 감소된다. 유견치가 편측으로 상실된 경우는 상기 현상 이외에, 영구 절치들이 조기 상실된 부위의 공간으로 경사지게 되어 정중선이 틀어지게 된다. 보통 4 mm 이하의 공간부족은 순차적인 유치의 disking과 passive lingual arch를 사용하여 leeway space를 보호하는 것만으로도 해결이 가능하며 4~6 mm 공간부족은 상기 술식과 함께 악궁의 전후방 및 측방확장으로 어느정도 해소할 수 있다.

• 복식
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• 제28권
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• pp.99-112
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• 1996

In this study I purpose a new approach to the study of Korean costume history which includes a statistical method used in the prac-tical measurement of excavated Po's and the analysis of their quantitative changes. In the framework used in this study I de-pend on the nineteen variables picked out from the typological and chronological analysis of excavated clothes. The interrelationship of the variables as well as the standard of each part and its deviation in other forms are may main concern. Other methods are also very useful in my thesis: Correlation analysis Regression analysis Discrimination analysis Cluster analysis Discrimination analysis Cluster analysis Factor analysis One way analysis of variance. The findings of my study can be summarized as follows: 1. Every type of po has a general tendency to have more broadened sleeves while it does not show any considerable changes in the total length and in the width of armholes. 2. In the Correlation analysis each part of Po's is handled separately accordign to its chronology and type. The Regreesion analysis makes it possible to provide the sizes of miss-ing parts in excavated clothes and the numeri-cal value of each part needed in the pattern making. 3. The Discrimination analysis of the Po's whose types are unknown leads to the con-clusion that Chongsam and Chikryong Po are classified into Chikryong Po whereas Hongui is classified into Jooui In addition I propose discriminational function by which the age classification is possible discovering the variables associated with time change. 4. Five items-Gerneral Park's clothes Taewongun's clothes and three others produced later for the purpose of preserving Korean costume are proved to be in a differ-ent group and hence analyzed separately in the visual grouping of changui which is done after the cluster analysis and the factor analysis. 5. The results of the one way analysis of variance reveal that there is a difference in each part from period: the back width the sleeve length the sleeve width thelean fig-ure the breasttie length the breasttie width outside quesset upper inside quesset lower outside neckband length insideneckband length etc.

• International journal of advanced smart convergence
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• 제10권2호
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• pp.108-122
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• 2021

With the development of 3D graphics software and the speed of computer hardware, it is an era that can be realistically expressed not only in movie visual effects but also in console games. In the production of such realistic 3D models, 3D scans are increasingly used because they can obtain hyper-realistic results with relatively little effort. Among the various 3D scanning methods, photogrammetry can be used only with a camera. Therefore, no additional hardware is required, so its demand is rapidly increasing. Most 3D artists shoot as many images as possible with a video camera, etc., and then calculate using all of those images. Therefore, the photogrammetry method is recognized as a task that requires a lot of memory and long hardware operation. However, research on how to obtain precise results with 3D photogrammetry scans is insufficient, and a large number of photos is being utilized, which leads to increased production time and data capacity and decreased productivity. In this study, point cloud data generated according to changes in the number and resolution of photographic images were produced, and an experiment was conducted to compare them with original data. Then, the precision was measured using the average distance value and standard deviation of each vertex of the point cloud. By comparing and analyzing the difference in the precision of the 3D photogrammetry scans according to the number and resolution of images, this paper presents a direction for obtaining the most precise and effective results to 3D artists.

• 수산경영론집
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• 제41권3호
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• pp.79-102
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• 2010

Abalone is a primary commodity that is almost traded as live fishes. So the application of 'addition' is common in local transaction of abalone. Nevertheless, an excessive application of addition leads to some social problems. The abalone industry is one of the most rapidly growing industry in fisheries. This growth is caused by propagation of sea cage and mechanization of feeding. As a result, the abalone distributers are increased. However, the distributers have great bargaining power, so they sometimes claim excessive addition rates to aquacultural abalone producers. Difference in fitted level of the addition rates between distributers and producers cause some problems as an aversion to shipping of abalone. Also, the words about addition have not clear definition yet. So many related terminologies, for example, addition, deviation, and loss, those have different meaning are in used. And unfortunately many industry insiders use the words, 'addition', mixed with other related terminologies on transaction. The main objective of this study is to clearly define addition's meaning on the abalone transaction and to analyze the correlations between the addition and the abalone prices, outputs, and exports. Analysis results show addition negatively affects abalone prices and outputs. Furthermore, addition contributes to abalone exports negatively contrary to expectation. Such results can provide information that 'stabilization of supply and price of abalone' is realistically better method than 'increasing of additional rates' to expand abalone exports. Negative correlations between variables tell that a dictionary definition of addition, a free as seller's benevolence, is divorced from reality of abalone industry. Therefore "Loss", that means preservation in unintentional loss of abalone objects, is more suitable than "Addition" on abalone transaction.