• 해양환경안전학회지
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• 제29권2호
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• pp.139-146
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• 2023

양식장 부표 등과 같은 해상의 소형 장애물을 탐지하고 거리와 방위를 시각화시켜 주는 해상물체탐지시스템은 선체운동으로 인한 오차를 보정하기 위해 3축 짐벌이 장착되어 있지만, 파도 등에 의한 카메라와 해상물체의 상하운동으로 발생하는 거리오차를 보정하지 못하는 한계가 있다. 이에 본 연구에서는 외부환경에 따른 수면의 움직임으로 발생하는 해상물체탐지시스템의 거리오차를 분석하고, 이를 평균필터와 이동평균필터로 보정하고자 한다. 가우시안 표준정규분포를 따르는 난수를 이미지 좌표에 가감하여 불규칙파에 의한 부표의 상승 또는 하강을 재현하였다. 이미지 좌표의 변화에 따른 계산거리, 평균필터와 이동평균필터를 통한 예측거리 그리고 레이저 거리측정기에 의한 실측거리를 비교하였다. phase 1,2에서 불규칙파에 의한 이미지 좌표의 변화로 오차율이 최대 98.5%로 증가하였지만, 이동평균필터를 사용함으로써 오차율은 16.3%로 감소하였다. 오차보정 능력은 평균필터가 더 좋았지만 거리변화에 반응하지 못하는 한계가 있었다. 따라서 해상물체탐지시스템 거리오차 보정을 위해 이동평균필터를 사용함으로써 실시간 거리변화에 반응하고 오차율을 크게 개선할 수 있을 것으로 판단된다.

• 한국환경보건학회지
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• 제7권1호
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• pp.21-31
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• 1981

This survey was carried out to investigate the temperature, pH value, nitrogen (ammonia, nitrite, nitrate), turbidity, color, chloride ion, $KMnO_4$ consumed, and hardness as chemical analysis of the tap water in Seoul city area during the period from September to Octobor, 1979, and to observe the differences among the values by the distance from the water purification plant and by the district supplied tap water from-the each water purification plant. The results obtained were as follows: 1) An average of the water temperature was $19.8\pm 0.2\circ$C. 2) An average of pH was $7.18\pm 0.02$. The difference among each district was statistically significant (p<0.01), but it was not observed among each distance. 3) An average of turbidity was $1.25\pm 0.12$ ppm. The difference among each district was highly significant (p<0.01), respectively, but not among each distance. 4) An average of color was $1.43\pm 0.16$ ppm, and there were statistically significant differences by the distance and by the district (p<0.01). 5) An average of ammonia nitrogen was $0.022\pm 0.005$ ppm. The differences among each distance, and district were statistically significant (P<0.01). 6) An average of nitrite nitrogen was $0.0050\pm 0.0013$ ppm, and the difference among each distance was highly significant (p<0.01), respectively, and each district showed statistical significance (p<0.01). 7) An average of nitrate nitrogen was $0.82\pm 0.08$ ppm. The difference among each district was significant (p<0.05), and each distance showed high significance (p<0.01). 8) An average of $KMnO_4$ consumed was $3.73\pm 0.16$ ppm, and the difference among each district was significant (p<0.05), but it was not observed among each distance. 9) An average of chloride ion was $8.56\pm 0.28$ ppm, and the difference among each district was higly significant (p<0.01), respectively, but it was not observed among each distance. 10) An average of hardness was $40.69\pm 1.17$ ppm, and there was statistically significant difference by each district (P<0.01), but not by distance. 11) The interrelation between temperature and pH of the tap water revealed the negative correlation from the coefficient of it as showed r=-0.6073 and p<0.01. 12) Except water temperature, there were negative correlationships between pH and other water qualities. 13) Correlation coefficients of $KMnO_4$ comsumed and ammonia nitrogen, nitrite nitrogen were statistically significant but that of $KMnO_4$ consumed and nitrate nitrogen showed no statistical correlationship. 14) Ammonia nitrogen seems to have high correlationship with nitrite nitrogen(r= +0.6669), but not with nitrate nitrogen. 15) Nitrate nitrogen seems to have statistically significant correlationship with nitrite nitrogen (r=+0.4959), but not with ammonia nitrogen. 16) The interrelation between chloride ion and hardness of the tap water revealed positive correlation from the coefficient of it as showed as r=+0.4888 and p<0.01.

• 대한수학교육학회지:학교수학
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• 제18권4호
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• pp.881-901
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• 2016

본 연구는 '시간, 거리, 속력'의 관계에 대한 학생들의 인식과 표현을 교수실험을 통하여 세밀하게 관찰한 연구이다. 이 과정에서 학생들의 '시간, 거리, 속력'의 관계에 대한 인식의 변화가 드러났으며, 학생들은 평균속력에 대하여 거리함수에서 구간의 양 끝점을 잇는 선분의 기울기라는 관점으로 인식하는 것 외에도 속력함수에서 사각형의 높이로 인식하여 '시간, 거리, 속력'을 이해하고 있음을 보여주었다. 이 과정에서 '거리=시간${\times}$속력'의 관계를 '거리=시간${\times}$평균속력'으로 확장하는 장면을 드러내었다. 본 연구는 제한된 소수 학생을 대상으로 교수실험을 진행하였지만, 학생들의 '시간, 거리, 속력'의 관계에 대한 인식과 표현의 변화 과정에 대한 관찰을 통하여 여러 시사점을 제시하였다. 이러한 연구 결과가 추후 미적분 학습 모델 구성을 위한 다양한 연구의 시발점이 되기를 기대해본다.

• Journal of information and communication convergence engineering
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• 제10권1호
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• pp.1-4
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• 2012

Given separated points divided by a line, called a wall, in a plane, we aim to make a gate in the wall to connect the separated points to each other. In this setting, the problem is to find a location for the gate that minimizes the average distance between the points. The problem is a variant of the well-known facility location problem, which is extensively studied in the fields of operations research, location theory, theoretical computer science, and so on. In this paper, we consider the $L^1$-distance of the points in the plane. The points are projected onto the wall and so the problem is transformed to a proximity problem of points on a line. Then it is shown that the transformed problem is related to the weighted median problem of points on the line. Therefore, we obtain an O(n log n)-time algorithm to solve our problem.

• 대한교통학회:학술대회논문집
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• 대한교통학회 1998년도 Proceedings The 4th International Transport Symposium
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• pp.91-99
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• 1998

Generally, the tons lifted and ton-kilometers are widely used to analyze the road freight transport. However, these two indicators are simply to show the road freight transport statistics rather than to explain the road freight transportation systems. In this study, the variables such as the number of distribution channel levels, the integral distance, tons in transport and the average transport distance are defined and estimated to investigate the road freight transport system of Korea. In order to compare the road transport system of Korea to other countries, the comparative study was conducted including USA, Japan, Holland and Taiwan. The major findings of this study are as follows; i) The number of distribution channel levels and integral distance of Korea and Taiwan have been increased, but the average transport distance decreased from 1971 to 1996 period. ii) On the contrary to Korea case, the number of distribution channel levels and integral distance of US, Japan and Holland have been decreased, but the average transport distance increased. iii) In the time-series model analysis shows that the number of distribution channel levels are statistically positively closely related to the logistics costs and the costs of transportation as a percentage of GDP.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제25권2호
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• pp.7-16
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• 2019

Purpose: The courtyard in the ward can light and ventilate in the central space and corridor of the ward. It is possible to improve the disadvantages of the existing double-corridor ward. Also, there is the advantage in that patients are able to contact with nature indoors and cause positive activities. So, the purpose of this study is quantitatively analyze the floor area and the average distance of nurse working of the courtyard in ward. Methods: The subjects are converted through the same criteria setting. And it investigate and analyze the influence of the courtyard in the ward through the analysis of the spatial composition. Result: The factors that affected the floor area increase are the planning courtyard, the corridor type and the dispersion of the medical rooms. The average distance of nurse working is more influenced by the nursing management system of the hospital than by the courtyard. So, It can improve according to the position and number of nurse station. Implications: It can be used as a primary data for courtyard plan in the ward for positive patient environment plan considering the floor area, average distance of nurse working.

• 한국동물학회지
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• 제24권2호
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• pp.91-98
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• 1981

Deer mice, Peromyscus maniculatus, 의 성체 571마리의 30개 morphometric 형질들을 이용한 cluster analyses에서 두가지의 similarity 행렬식 (Average taxonomic distance와 Correlation coefficient 행렬식)을 이용한 dendrogram이 서로 다르다는 것이 확인되었다. 이들 두가지의 행렬식 중에서 taxarks의 형태적인 유연관계를 나타내는 하나의 dendrogram만을 선택하기 위한 한 객관적방법이 제안되었다. 즉 principal component analysis에 의한 결과를 비교할 표준결과로 이용하는 방법이다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제18권2호
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• pp.217-223
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• 1996

In order to evaluate the changes before and after secondary operations in the patients with cleft lip objectively using full face photographs, the author analyzed results of improvement on nasal width and mouth width and asymmetry of nostril. 1. The ration of asymmetry of thenostril is changed from average 1.24 preoperatively to average 1.08 postoperaively : 61.2% is improved postoperatively. 2. The ratio of nasal width compared with intermedial canthal distance is changed from average 1.15 preoperatively to average 1.10 postoperatively : 3.8% is reduced posteroperatively. 3. The ratio of mouth width compared with intermedial canthal distance is changed from average 1.08 preoperatively to average 1.03 postoperathvely : 4.1% is reduced posteroperatively.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1-6
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• 2004

In this study, the intrinsic static/dynamic fracture toughness of Al 7175=T74 is evaluated from the apparent static/ dynamic toughness of notched specimen, The critical average stress fracture model is suggested to establish the relationship to predict the intrinsic fracture toughness from the apparent fracture toughness of a notched specimen. The critical average stress fracture model is established using the relation between the notch root radius and the effective distance calculated by finite element analysis. Also, effective distance is applied to estimate the failure criterion for the combustion pipe with notch. It is conclude that the true fracture toughness can be estimated from test results of apparent fracture toughness measured by using a notched specimen. Also, the effective In this study, the intrinsic static/dynamic fracture toughness of Al 7175=T74 is evaluated from the apparent static/ dynamic toughness of notched specimen, The critical average stress fracture model is suggested to establish the relationship to predict the intrinsic fracture toughness from the apparent fracture toughness of a notched specimen. The critical average stress fracture model is established using the relation between the notch root radius and the effective distance calculated by finite element analysis. Also, effective distance is applied to estimate the failure criterion for the combustion pipe with notch. It is conclude that the true fracture toughness can be estimated from test results of apparent fracture toughness measured by using a notched specimen. Also, the effective distance can be used to evaluate the failure criterion of structure with notch.

• 대한임베디드공학회논문지
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• 제13권2호
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• pp.83-91
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• 2018

With the development of IT (Information Technology) technology, embedded system and network technology are combined and used in various environments such as military environment as well as everyday life. In this paper, we propose a new airdropped distributed mobility model (ADMM) modeling the dispersion falling of the direct shot of a cluster bomb, and we compare and analyze some representative MANET routing protocols in ADMM in ns-3 simulator. As a result of the analysis, we show OLSR routing protocol is promising in ADMM environment in the view points of packet delivery ratio (PDR), end to end delay, and jitter. In addition, we propose a new adaptation scheme for OLSR, AND-OLSR (Average Node Distance based adaptive-OLSR) to improve the original OLSR in ADMM environment. The new protocol calculates the average node distance, adapts the period of the control message based on the average node distance increasing rate. Through the simulation study, we show that the proposed AND-OLSR outperforms the original OLSR in PDR and control message overhead.