• 로봇학회논문지
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• 제2권2호
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• pp.161-167
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• 2007

It is dangerous that an inspector overhauls defects and condition of the inner parts of an oil tanker because of many harmful gases, complex structures, and etc. However, these inspections are necessary to many oil tankers over old years. In this study, we proposed the design of mobile robot for inspection of CAS in oil tanker. The developed CAS inspection mobile robot has four modules, a measurement module of oil tanker's thickness, a corrosion inspection module, a climbing module of the surface on a wall, and a monitoring module. In order to get over at a check position, the driving control algorithm was developed. Magnetic wheels are used to move on the surface of a wall. This study constructed a communication network and the monitoring program to operate the developed mobile robot from remote sites. In order to evaluate the inspection ability, the experiments about performance of CAS inspection using the developed mobile robot have been carried out.

• Asia Marketing Journal
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• 제17권2호
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• pp.63-71
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• 2015

In this research, we explore whether mere exposure to external cues with vertical progress (e.g., moving upward or moving downward) can influence individuals' persistence to complete focal tasks. Drawing on the theory of embodied cognition, we propose that, a moving-upward (vs. downward) cue activates the abstract concept of difficulty, which is associated with the physical experience of climbing uphill (vs. downhill). Due to this association between moving uphill and difficulty, merely exposing individuals to the moving-upward cue can induce greater feeling of difficulty and this greater difficulty, in turn, reduce individuals' persistence, compared to exposing individuals to the moving-downward cue. Across three studies, we find supporting evidence for the effect of the external cues with vertical progress on individuals' performance both in physical tasks and in a cognitive task.

• International journal of advanced smart convergence
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• 제12권4호
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• pp.451-457
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• 2023

Global warming is causing abnormal climates such as floods, droughts, and typhoons all over the world. According to some scientists, carbon dioxide emitted from automobiles is the main cause of global warming. To cope with this, each country is making efforts to replace the existing fossil fuel-powered engine-driven cars with electric vehicles. In order to commercialize small electric vehicles in Korea, it is necessary to solve many problems such as improvement of hill climbing capacity and improvement of power performance. In this study, we propose a proprietary model for a continuously variable transmission(CVT) of a small electric vehicle that can be operated on hills, in which a spring is mounted on a driving pulley and a driven pulley. A prototype of the CVT model using a spring was manufactured and attached to a small electric vehicle body.

• Journal of Biosystems Engineering
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• 제37권5호
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• pp.287-295
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• 2012

Purpose: Some of the most representative approaches are to apply next generation technologies to save energy consumption, fully automated control system to appropriately maintain environmental conditions, and autonomous assistance system to reduce labor load and ensure operator's safety. Nevertheless, improvement of upcoming method for soil cultured greenhouse has not been sufficiently achieved. Geometrical complexity of ground in protected crop cultivation might be one of the most dominant factors in design of autonomous vehicle. While there is a practical solution fairly enough to promise an accurate travelling, such as autonomous sprayer guided by rail or induction coil, for various reasons including the limitation of producer's budget, the previously developed sprayer has not been widely distributed to market. Methods: In this study, we developed an autonomous sprayer considering travelling performance on geometrical complexity of ground in soil cultured greenhouse. To maintain a stable travelling and to acquire a real time feedback, common wire with 80 mm thick and body frame and sprayer boom. To evaluate performance of the prototype, tracking performance, climbing performance and spraying boom's uniform leveling performance were individually evaluated by corresponding experimental tests. Results: The autonomous guidance system was proved to be sufficiently suitable for accurate linear traveling with RMS as lower than approximately 10 cm from designated path. Also the prototype could climb $10^{\circ}$ of ground's slope angle with 40 kg of water weight. Uniform leveling of spraying boom was successfully performed within $0.5^{\circ}$ of sprayer boom's slope. Conclusions: Considering more complex pathways and coarse ground conditions, evaluations and improvements of the prototype should be performed for promising reliability to commercialization.

• 제어로봇시스템학회논문지
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• 제17권6호
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• pp.587-595
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• 2011

In this paper, we focus on the issue of automatic selection for multi-level threshold, and we greatly improve the efficiency of Otsu's method for image segmentation based on genetic algorithm. We have investigated and evaluated the performance of the Otsu and Valley-emphasis threshold methods. Based on this observation we propose a method for automatic threshold method that segments an image into more than two regions with high performance and processing in real-time. Our paper introduced new peak detection, combines with evolution algorithm using MAGA (Modified Adaptive Genetic Algorithm) and HCA (Hill Climbing Algorithm), to find the best threshold automatically, accurately, and quickly. The experimental results show that the proposed evolutionary algorithm achieves a satisfactory segmentation effect and that the processing time can be greatly reduced when the number of thresholds increases.

• 로봇학회논문지
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• 제5권3호
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• pp.270-277
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• 2010

Various robot platforms have been designed and developed to perform given tasks in a hazardous environment for the purpose of surveillance, reconnaissance, search and rescue, and etc. We have considered a terrain adaptive hybrid robot platform which is equipped with rapid navigation on flat floors and good performance on overcoming stairs or obstacles. Since our special consideration is posed to its flexibility for real application, we devised a design of a transformable robot structure which consists of an ordinary wheeled structure to navigate fast on flat floor and a variable tracked structure to climb stairs effectively. Especially, track arms installed in front side, rear side, and mid side are used for navigation mode transition between flatland navigation and stairs climbing. The mode transition is determined and implemented by adaptive driving mode control of mobile robot. The wheel and track hybrid mobile platform apparatus applied off-road driving mechanism for various professional service robots is verified through experiments for navigation performance in real and test-bed environment.

• 대한임베디드공학회논문지
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• 제8권5호
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• pp.273-283
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• 2013

The traditional medical equipments are devices used by medical professionals but not used in public environment. Common people, however, require light-weight medical devices to make healthcare for themselves nowadays. Those medical devices are used to monitor personal health status such as blood pulse, blood pressure, diabetes. Also, some of them are operated in mobile environment called u-healthcare. This paper implements a portable healthcare system composed of $SpO_2$(Saturation of Partial Pressure Oxygen) sensors and a gateway for detecting hypoxemia during people's leasure activity such as climbing or hiking. The $SpO_2$ sensor is designed as watch style to support dynamic exercise and the gateway is designed as necklace style to support the elderly. The result of a performance evaluation shows that the performance of the $SpO_2$ sensor using reflection technology is not lower than that of a clairvoyant styled $SpO_2$ sensor.

• 정보과학회 논문지
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• 제43권4호
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• pp.480-488
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• 2016

탐색 기반 테스팅은 넓은 탐색 범위에서 효과적으로 테스트 데이터를 생성하는 대표적인 기술중 하나이다. 탐색 기반 테스팅의 성능이 프로그램의 구조적 특성에 영향을 받는 것이 알려져 있음에도 구조적 특성을 고려한 탐색 기반 테스팅 비교 연구는 제한적으로 수행되었다. 본 연구는 탐색 기반 테스팅 비교를 통해 테스트 대상의 구조적 특성 차이에 따른 최적 알고리즘을 분석하고자 한다. 실험 결과의 일반화를 위해 탐색 성능에 영향을 주는 4가지 메트릭 값을 조합하여 19,800개의 테스트 대상 프로그램을 자동 생성하였다. 실험 결과 복잡도가 높은 프로그램을 20,000번 이하의 횟수로 분석하였을 경우에는 유전 알고리즘이 가장 우수한 성능을 보였으나 50,000번 이상 분석하였을 경우에는 유전 담금질 기법과 담금질 기법이 다른 알고리즘들 보다 우수한 성능을 보였다. 복잡도가 낮은 프로그램에서는 유전 담금질 기법, 담금질 기법, 언덕 오르기 방법이 다른 알고리즘들 보다 우수한 성능을 보였다.

• 한국지능시스템학회논문지
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• 제20권1호
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• pp.42-47
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• 2010

마이크로 마우스를 이용한 다수의 미로 경진대회가 개최되어 미로 탐색 알고리즘의 성능이 비교되고 있으며, 미로 탐색 알고리즘은 좌(우)수법, 구심법, 언덕오르기 등을 기본으로 하여 다양한 형태로 적용되어 사용되고 있다. 하지만 미로 탐색알고리즘을 적용하여 테스트하기 위한 소프트웨어 플랫폼이 없어서 프로그램을 직접 개발하거나 하드웨어를 통해 알고리즘의 성능을 테스트해야 하는 불편함을 겪는다. 본 연구에서는 하드웨어로 구현이 어려운 다양한 형태의 미로 제작과 알고리즘의 손쉬운 적용이 가능하고, 스텝, 연산 횟수, 탐색 시간의 평가가 가능한 미로 탐색 알고리즘을 위한 플랫폼을 개발하였다. 플랫폼은 메인 레이어, 인터페이스 레이어, 사용자 레이어의 분리 구조로 되어 알고리즘을 쉽게 교체적용 할 수 있는 장점이 있다. 플랫폼의 실험을 통하여 미로 탐색 알고리즘들의 성능을 평가하고 분석하여 알고리즘의 개발 및 실험에도 적용할 수 있음을 확인하였다.

• 대한물리치료과학회지
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• 제19권2호
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• pp.55-61
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• 2012

Background : The purpose of this study is to provide the basic data according to cognitive function, that will help activities of daily living of the elderly through the comparative study of activities daily living and functional training. Methods : The subjects of this study 122 patients 65 years old or more ADL and cognitive function assessment was evaluated. They were registered in the Elderly in nursing homes and welfare centers, located in Gyeonggi. All study participants had a sufficient explanation for the purposes of research and evaluation methods and procedures for the elderly. The survey period 17 October to 11 November 2011 was conducted through face-to-face survey was conducted. Results : Cognitive function according to the K-MMSE score of 24 points or more, 23 to 18 points, 17 points or less were classified. Ability to perform activities of daily living (personal hygiene, bathing, toilet use, stair climbing, dressing, stool control, urinary control, gait, chair/bed, etc.) according to the degree of cognitive function by evaluating the ability to perform daily living compared results in all variables were statistically significant (p<.5). Conclusion : As a result, the higher cognitive functions can be seen that the higher the ability to perform activities of daily living.