• Journal of Satellite, Information and Communications
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• v.6 no.2
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• pp.60-65
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• 2011

Wireless devices can communicate between each other without existing infrastructure in mobile Ad-hod network. Ad hoc networks can be used under difficult conditions, where it is difficult to construct infrastructures, such as shadowing areas, disaster areas, war area, and so on. In order to support to considerable and various wireless services, more spectrum resources are needed. However, efficient utilization of the frequency resource is difficult because of spectrum scarcity and the conventional frequency regulation. Ad-hoc networks employing cognitive radio (CR) system that guarantee high spectrum utilization provide effective way to increase the network capacity. In this paper, to improve detection performance of the energy detection which is widely used in CR based ad-hoc network, we propose multiple antenna system for CR based ad-hoc networks.

• Journal of KIISE:Information Networking
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• v.29 no.2
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• pp.188-196
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• 2002

As networked virtual environment (NVE) scales in terms of users and network latency, a key aspect to consider is scalability for interactive performance because a large number of objects likely impose heavy burden especially on the network and computational resources. To improve the scalability, various relevance-filtering mechanism have been proposed. However, the existing filtering mechanism do not scale well in terms of interactive performance as the number of users increase and crowds in a specific place. In this paper, we propose a new scalable filtering scheme which reduces the number of messages by dynamically grouping users based on their interests and distance. Within a group, members communicate with each other with high fidelity. However, a representative sends up-to-dated group information of members with low transmission frequency when they are not of immediate interest but are still within the interest area. The representative is elected from members of the group in distributed manner. The proposed scheme enhances the interactive performance scalability of large-scale NVE systems as much as 18% compared with the existing approach.

• Journal of Digital Convergence
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• v.19 no.8
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• pp.225-234
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• 2021

Due to pandemic situations, the development of home robots that can make the house an optimized space for various activities is active. This study aims to confirm the effectiveness of approach or avoidance behavior for feedback positioning on the user experience, depending on the context in which the robot performs the task. Based on two types of the task contexts(Reactive vs. Proactive) and three types of robot feedback positioning(No move vs. Avoidance vs. Approach), six different scenarios were designed for experimental study. Likeability, perceived intelligence, rapport, negative attitude and predictability of behavior are measured for each conditions. The result showed the main effects of perceived intelligence, rapport, predictability in the context of tasks, and of likability, perceived intelligence, rapport in robot feedback positioning. The interaction effects were shown in likeability and perceived intelligence. In conclusion, approach-avoidance experiences can also be applied to robot behaviors as well, and the negative effects of avoidance have been significantly confirmed.

• Journal of Industrial Convergence
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• v.20 no.6
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• pp.17-25
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• 2022

As social problems related to the digital divide are increasing, the elderly are facing various problems as an information alienated group. In particular, there is a need to strengthen the ability to critically understand and accept information. In this study, using the 2020 media panel survey, the effects of digital literacy in the elderly on critical thinking disposition of information were analyzed, focusing on the moderating effect of need for cognition. As a results of the analysis, it was confirmed that the operational and the information skill had a positive effect on the critical thinking disposition of information. Also, as a result of analyzing the moderating effect of NFC(Need for Cognition), it was found that NFC strengthens the influence of operational skill and reduces the influence of information skill. This suggests that the digital literacy education for the elderly needs to change from strengthening accessibility to improving information judgment.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.2D
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• pp.147-154
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• 2008

A variety of activity happens around the sidewalk in the city. Particularly, a large variety of activity happens in shopping area, but it causes an obstruction of economical revitalization since the pedestrians require time and cost to find what they want. So, this study will develop the path searching method to minimize the economical loss of shoppers by providing the significant path and supporting the walking movement. Firstly, consider existing network expression techniques and approach three points which are physical and environmental factor, the recognition of the pedestrians' space when changing the direction, and the recognition of restriction of vision and accessibility. Try to design the network DB and simulate the algorithm. As a result, it is now possible to do the path searching that considers variety of recognition factors and show the method how to make the path-searching algorithm for pedestrian.

• The Journal of the Korea Contents Association
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• v.13 no.10
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• pp.434-443
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• 2013

The purpose of this study is to investigate the effectiveness of the way-finding exercise using a map in rehabilitation of cognitive function and activities of daily living in patients with a stroke. For the seven patients diagnosed with hemiplegia from a stroke, we executed the way-finding exercise using a map in the hospital, three times a week for two weeks. Loewenstein Occupational Therapy Cognitive Assessment(LOTCA) and Functional Independence Measure(FIM) were used to measure the cognitive function and performance of activities of daily living before and after intervention. For the visual perception area and the spatial relations of the spatial perception area of LOTCA, scores were significantly higher than before intervention(p<.05). For the walk/wheelchair of locomotion area and the problem solving of the social cognition area of FIM, scores were significantly higher than before intervention(p<.05). The results of this study show that a way-finding exercise for patients with a stroke is a useful therapeutic approach by enhancing cognitive function and performance of activities of daily living.

• Korean journal of psychology:General
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• v.36 no.2
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• pp.241-270
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• 2017

In this study we investigated the structural relationship between the Big Five personality traits which is a pretrauma characteristic, posttraumatic cognition, rumination, posttraumatic growth(PTG), and posttraumatic stress disorder(PTSD) symptoms. The participants were 1,000 adults who experienced traumatic event. For statistical analysis we set the research model with the Big Five personality traits affecting deliberate rumination through posttraumatic cognition and intrusive rumination. Competing model was set without the path from intrusive rumination to deliberate rumination. The results indicated that rumination and posttraumatic cognition did not mediate the relationship between extraversion, agreeableness, conscientiousness and PTG, PTSD symptoms. Second, there was a mediating effect of intrusive rumination between openness to experience and PTSD symptoms. Moreover, the pathway to intrusive rumination, deliberate rumination, and PTG from openness to experience was also significant. Third, the pathway to posttraumatic cognition, event-related rumination, and both PTSD symptoms and PTG from neuroticism was significant. These results support the cognitive process of PTG model In the end we discussed the implication and limitations of the study.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04c
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• pp.349-351
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• 2003

X3D는 XML 기반의 VRML(Virtual Reality Modeling Language) 차세대 언어로서 인터넷을 통해 동적이고 상호작용 가능한 실시간 가상 환경을 제공해 준다. 본 논문에서는 X3D기반 가상 환경이 제공하는 상호작용을 변경 또는 확장 가능한 새로운 인터페이스 모델을 제시한다. 본 논문에서 제시하는 모델은 X3D 가상 환경에서 사용자 재정의를 통한 상호작용, 새로운 멀티 모달 인터페이스로의 확장, 그리고 상황 인지 가상환경을 위한 상호작용 모델로서 사용될 수 있다.

• Information and Communications Magazine
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• v.34 no.6
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• pp.51-57
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• 2017

본고에서는 사물 인터넷 기술을 기반으로 한 실종자 탐색 기술과 서비스의 현황을 살펴보고 스마트폰 기반 실종자 탐색 서비스의 필요성과 시스템 구성 및 구현 방안에 대해 살펴 본다. 이 서비스는 실종자가 소지한 발신기 신호를 인지하는 수신 인프라의 종류에 따라 실종자 탐지 서비스의 비용, 실효성 등에 큰 영향을 받는다. 수신 인프라로 이동통신망, LoRa 망, 블루투스 망, 그리고 스마트폰을 사용하는 각 방안의 구조와 장단점을 살펴 본다.

• Journal of the korean veterinary medical association
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• v.41 no.12
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• pp.1142-1147
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• 2005

생명체 안에는 정맥혈과 동맥혈이라는 두 가지 종류의 혈액이 흐른다. 여기에는 신체 내 세 가지 기관이 관여하는데, 간은 영양과 성장의 임무를 심장은 생명의 원동력을 뇌는 인지와 이성을 담당한다. 영양과 성장은 간에서 형성되는 '정맥혈'을 통해 형성되고 생명의 원동력은 심장에서 형성되는 '동맥혈'을 통해 전신으로 퍼진다. 이 혈액들은 심장으로 다시 돌아오지 않고 온 몸에 퍼져 소비된다. 혈액은 심장이 이완될 때 심장 안으로 빨아들여진다. 심장은 혈액을 펌프질하는 기능이 없으며 동맥이 그 스스로가 '박동성'을 가지고 혈액을 밀어낸다. 좌심실에서 정맥혈과 프네우마(Pneuma)가 섞이게 되는데 심장 오른쪽 심실과 심방의 정맥혈은 좌심실과 우심실 사이 중격(심실중격, interventricularseptum)의 작은 구멍을 통해 좌심실로 이동한다.