• 한국측량학회지
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• 제24권1호
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• pp.27-36
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• 2006

대부분의 국내 다목적 댐은 유역면적이 넓고 강우기 집중강우로 인하여 토양의 상당량이 유실되며, 유실된 토양입자는 하천이나 댐 저수지에 장기간 축적되어 저수용량의 감소와 수질관리에 어려움을 야기한다. 지금까지의 퇴적물 조사방법은 관측주기가 길고 측선법에 의한 퇴적정도를 관측하여 정확성 확보에 어려움이 많았다. 본 연구에서는 댐 저수지 퇴적물에 대한 정밀 관측을 위해 항공 LiDAR 기술을 활용하였으며, 퇴적물의 근원지를 추적하고 그 이동경로를 연구하였다. 토양유실에 영향을 주는 토양, 피복, 지형특성을 보다 세밀하게 분류함으로써 유실되는 퇴적물의 정확한 분포량과 유실 위치를 파악할 수 있었으며, 정확도가 향상된 고정밀 DEM을 이용하여 수로화된 흐름을 추적함으로써 퇴적물의 유실경로 분석에 신뢰성을 유지할 수 있었다.

• 한국수학교육학회지시리즈A:수학교육
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• 제56권3호
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• pp.281-300
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• 2017

This study analyzed the difficulties of middle school students in computer simulation of the law of large numbers through eye movement analysis. Some students did not attend to the simulation results and could not make meaningful inferences. It is observed that students keep the existing concept even though they observe the simulation results which are inconsistent with the misconceptions they have. Since probabilistic intuition influence student's thinking very strongly, it is necessary to design a task that allows students to clearly recognize the difference between their erroneous intuitions and simulation results. In addition, we could confirm through eye movements analysis that students could not make meaningful observations and inferences if too much reasoning was needed even though the simulation included a rich context. It is necessary to use visual representations such as graphs to provide immediate feedback to students, to encourage students to attend to the results in a certain intentional way to discover the underlying mathematical structure rather than simply presenting experimental data. Some students focused their attention on the visually salient feature of the experimental results and have made incorrect conclusion. The simulation should be designed so that the patterns of the experimental results that the student must discover are not visually distorted and allow the students to perform a sufficient number of simulations. Based on the results of this study, we suggested that cumulative relative frequency graph showing multiple results at the same time, and the term 'generally tends to get closer' should be used in learning of the law of large numbers. In addition, it was confirmed that eye-tracking method is a useful tool for analyzing interaction in technology-based probabilistic learning.

• 산업경영시스템학회지
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• 제34권4호
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• pp.35-41
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• 2011

The purpose of this study was to examine drivers' driving behaviors and eye-movements according to driving speed and navigation- position while operation of the navigation in driving. For this purpose, two driving conditions (low-speed and high-speed) and two navigation-positions (top and bottom location of the center console) were set. Drivers' driving behaviors (speed, speed variation, coefficient of variation, and the number of collisions) and eye-movements (overall eye pattern, the average scanning time of navigation, and the number of gaze-out on the road for more 2 seconds) were measured. As a result, when the navigation was located at the bottom of the console, difficulties of lateral control was appeared in low-speed driving condition, and the that of longitudinal control was appeared in high-speed driving condition. In addition, above situation made the drivers' scanning times of navigation long, increased the number of gaze-out on the road for more 2 seconds, and made overall eye pattern monotonous. These results could be interpreted that the manipulation of the navigation at the bottom of console cause reduced attention capacity due to the cognitive load.

• 한국정밀공학회지
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• 제23권11호
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• pp.58-67
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• 2006

Due to the variety of signal processing and complicated mathematical analysis, it is not easy to accomplish 3D bin-picking with non-contact sensor. To solve this difficulties the reliable signal processing algorithm and a good sensing device has been recommended. In this research, 3D laser scanner and CCD camera is applied as a sensing device respectively. With these sensor we develop a two-step bin-picking method and reliable algorithm for the recognition of 3D bin object. In the proposed bin-picking, the problem is reduced to 2D intial recognition with CCD camera at first, and then 3D pose detection with a laser scanner. To get a good movement in the robot base frame, the hand eye calibration between robot's end effector and sensing device should be also carried out. In this paper, we examine auto-calibration technique in the sensor calibration step. A new thinning algorithm and constrained hough transform is also studied for the robustness in the real environment usage. From the experimental results, we could see the robust bin-picking operation under the non-aligned 3D hole object.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제40권2호
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• pp.83-86
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• 2014

There are some difficulties in approaching and removing the lesion in infratemporal fossa because of its anatomical location. After wide excision of tumor lesion, it is also difficult for reconstruction of mandibular condyle and cranium base on infratemporal fossa. Besides, there are some possibilities of cerebrospinal fluid leakage, intracranial infection and bone resorption. It is also challenging for functional reconstruction that allows normal mandibular movement, preventing mandibular condyle from invaginating into the skull. In this report, we present 14-month follow-up results of a patient who had undergone posterior segmental mandibulectomy including condyle and infratemporal calvarial bone and mandible reconstruction with free vascularized costochondral rib and calvarial bone graft to restoration of the temporomandibular joint area.

• Journal of Pharmaceutical Investigation
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• 제31권2호
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• pp.73-80
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• 2001

Lung perfusion scanning, invariably combined with ventilation studies provides a reliable and non-invasive mean to diagnose lung related pathologies despite the availability of modern techniques such as angiography, magnetic resonance imaging, magnetic resonance angiography, and helical (spiral) computed tomography. The technique involves the generation of images by radiations emitted from radioisotopes introduced in to the lungs. Various radiopharmaceuticals have been proposed and designed to incorporate $Tc^{99m}$ in to macroparticulate form for lung perfusion imaging. However, most of these have associated difficulties such as reproducibility of the product with regards to particle size distribution and poor elimination from the lung capillary bed. $Tc^{99m}$ macroaggregated albumin $(Tc^{99m}-MAA)$ is used extensively for clinical lung perfusion imaging and is considered as the radiopharmaceutical of choice. It is non-toxic, safe, and being biodegradable, is easily eliminated from the lung capillary bed by proteolytic enzyme metabolism and by mechanical forces due to lung movement.

• 수산해양교육연구
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• 제15권1호
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• pp.81-100
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• 2003

It is undeniable that IUU Fishing are threatening so many legal fishermen' economic livelihood, negatively impact on conservation and protection of the fishery stock and ecosystem itself. Especially, negative impact of IUU Fishing resulted from the increasing fishery activities on the high seas. The Korea case of Coastal and Off-shore Fisheries, difficulties in conserving and controlling the fishery stock was brought about. Simultaneously, it is the fact that there are so many damage such as the reduction of fish Stock management program's effect, dissatisfaction of legal fishermen, over-exploiting of fish stock. Related with this kind of problem, FAO had adopted "International Plan of Action to Prevent, Deter and Eliminate Illegal, Unreported and Unregulated Fishing(2001)". From this reason, Korea also needs to make actual efforts to prevent IUU Fishing. i.e. each nation should develop Korea action plan by Feb. 2004 and impliment it, report on implementation toward FAO. This Paper will review the definition of the IUU stipulated by "International Plan of Action on Illegal, Unreported and Unregulated Fishing" and study Korea cases of the IUU fishing. Finally, the analysis of Korea's implementation will be done, centering around the contents stated on the International Action Plan. The significance of this paper is to grope the political countermeasures against international movement of the IUU fishing prevention.

• 대한치과보철학회지
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• 제21권1호
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• pp.67-72
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• 1983

Path of insertion(1) can be defined that the direction of movement of an appliance from the point of initial contact of its rigid parts with the supporting teeth to the place of final rest. Krol(2) described that in the conventional path of insertion, all the rests are seated more or less simultaneously but in the use of the rotational path one segment of the partial denture is seated first then the remainder of the prosthesis is rotated into position. The rotational path of insertion is limited primarily to the tooth borne prosthesis. Its great advantages are the elimination of anterior clasps to improve ethetic and reduction of tooth coverage to minimize plaque accumulation. Either a rigid minor connector or proximal plate provides retention through its intimate contact with a proximal tooth surface below the height of contour as indicated at a o-degree tilt. A specially designed rest in conjunction with this retentive component satisfies the basic requirements of clasp design. The purpose of this study was a clinical evaluation of rotational path removable partial dentures. Author delivered rotational path removable partial dentures to three different cases of patients and evaluated function of the dentures, difficulties of removal and insertion of the dentures and supporting structures of the abutment teeth by means of clinical and X-ray examinations for eighteen months. According to the examination data author came to the conclusion that the prognosis of the rotational path removable partial dentures was excellent.

• 로봇학회논문지
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• 제8권4호
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• pp.283-291
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• 2013

Methods for measuring or estimating of ground shape by a laser range finder and a vision sensor(exteroceptive sensors) have critical weakness in terms that these methods need prior database built to distinguish acquired data as unique surface condition for driving. Also, ground information by exteroceptive sensors does not reflect the deflection of ground surface caused by the movement of UGVs. Thereby, UGVs have some difficulties regarding to finding optimal driving conditions for maximum maneuverability. Therefore, this paper proposes a method of recognizing exact and precise ground shape using Inertial Measurement Unit(IMU) as a proprioceptive sensor. In this paper, firstly this method recognizes attitude of a robot in real-time using IMU and compensates attitude data of a robot with angle errors through analysis of vehicle dynamics. This method is verified by outdoor driving experiments of a real mobile robot.

• 대한한의학원전학회지
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• 제23권5호
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• pp.67-82
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• 2010

Globalization describes a process by which regional cultures have become integrated through a global network of communication. In order to communicate among different cultural groups, standardization of terminology is one of the most important steps among its processes. In the field of oriental medicine, there have been continuous efforts to communicate through various methods. Translation of oriental medical classics is one of the significant approaches in terms of transmitting medical theories and clinical experiences of thousands of years to the people of different cultural backgrounds. However, previous translation studies have had difficulties in delivering its underlying principles and assumptions due to lack of standardization of terminology. "WHO International Standard Terminologies on Traditional Medicine in the Western Pacific Region(WHO-IST)" is the outcome of developing standard terminologies on oriental medicine based on mutual agreement of researchers of Korea, China and Japan. As a movement to find more efficient methodology for communication between heterogeneous communities, this study aims to translate parts of "Classic of difficult issues(難經)" into English adopting "WHO-IST" hoping to set a model of translation study.