스키 시뮬레이터 운동 시 하지 운동특성 분석 및 관성센서 파라미터를 이용한 스키 숙련도 평가

김정윤,안순재,박선우,신이수,김규석,김영호,Kim, Jungyoon,Ahn, Soonjae,Park, Sunwoo,Shin, Isu,Kim, Gyoosuk,Kim, Youngho 대한의용생체공학회 2014 의공학회지 Vol.35 No.3

In this study, joint angles of the lower extremity and inertial sensor data such as accelerations and angular velocities were measured during a ski simulator exercise in order to evaluate the skill of skiers. Twenty experts and twenty unskilled skiers were recruited for the study. All expert skiers held the certificates issued by the Korea Ski Instructors Association. A three-dimensional motion capture system and two inertial sensors were used to acquire joint movements, heel acceleration and heel angular velocity during ski simulator exercises. Pattern variation values were calculated to assess the variations in ski simulator motion of expert and unskilled skiers. Integral ratio of roll angular velocity was calculated to determine the parallel alignment of the two feet. Results showed that ski experts showed greater range of motion of joint angle, peak-to-peak amplitude(PPA) of heel acceleration and PPA of heel angular velocity than unskilled skiers. Ski experts showed smaller pattern variations than unskilled skiers. In addition, the integral ratio of roll angular velocity in ski experts was closer to 1. Inertial sensor data measurements during the ski simulator exercises could be useful to evaluate the skill of the skier.

SAF를 위한 자동계획기법 구현 사례

김정윤,최대회,이상진,정성훈,Kim, Jungyoon,Choi, Daehoe,Lee, Sangjin,Jeong, Sunghoon 한국시뮬레이션학회 2014 한국시뮬레이션학회 논문지 Vol.23 No.4

Our Automatic Replanning enables simulation entities to execute goal oriented behavior planning by dynamic behavior linking. Existing methods especially in Semi-Automated Forces (SAF) are mainly executing strict plans which are given at initial stage, thus they are not effective to cope with contingencies especially in a human in the loop simulation where humans interrupt. Moreover, those usually suffer from explosion of behavior combination in attempt to describe all possible countermeasures, and such combinations may be prone to being inconsistent to the situations. Our method generates behavior sequence in which behavior are linked from the goal in the manner of back-propagation. Each behavior has tags of pre/post-conditions. The tags are linked dynamically according to a certain contingency. The method is being applied to a national defense research project to show feasibility. 본 연구는 모의개체로 하여금 동적행위연결을 통한 목적지향 행위계획을 수행토록 하는 기법의 구현사례로서 재계획기법을 소개한다. 기존의 행위처리기법, 특히 Semi-Automated Forces (SAF)에서는 모의 초기에 주어진 정해진 계획을 단순히 수행하는 수준에서 크게 벗어나지 않는다. 따라서 인간의 판단 같은 예측불허 상황이 발생하는 (Human in the loop) 모의에서 기존 기법은 상황대처에 미흡하다. 또한 그러한 기법은 돌발상황 대응을 위한 광범위한 경우의 수를 고려하다보면 행위조합 폭증 문제를 겪을 수 있으며, 그러한 조합이 상황에 부합하지 않을 수 있다. 재계획기법은 역전파(back-propagation)를 활용, 목표달성을 위해 필요한 행위들을 검색, 연계하는 자동계획기법 구현사례이다. 이 기법은 행위에 태그(pre/post-conditions)를 부여, 동적으로 행위들을 연결한다. 본 논문은 기법의 실효성 입증을 위해 국방분야의 연구과제에 적용된 성과를 소개한다.

효율적인 feature map 추출 네트워크를 이용한 2D 이미지에서의 3D 포인트 클라우드 재구축 기법

김정윤,이승호,Kim, Jeong-Yoon,Lee, Seung-Ho 한국전기전자학회 2022 전기전자학회논문지 Vol.26 No.3

In this paper, we propose a 3D point cloud reconstruction technique from 2D images using efficient feature map extraction network. The originality of the method proposed in this paper is as follows. First, we use a new feature map extraction network that is about 27% efficient than existing techniques in terms of memory. The proposed network does not reduce the size to the middle of the deep learning network, so important information required for 3D point cloud reconstruction is not lost. We solved the memory increase problem caused by the non-reduced image size by reducing the number of channels and by efficiently configuring the deep learning network to be shallow. Second, by preserving the high-resolution features of the 2D image, the accuracy can be further improved than that of the conventional technique. The feature map extracted from the non-reduced image contains more detailed information than the existing method, which can further improve the reconstruction accuracy of the 3D point cloud. Third, we use a divergence loss that does not require shooting information. The fact that not only the 2D image but also the shooting angle is required for learning, the dataset must contain detailed information and it is a disadvantage that makes it difficult to construct the dataset. In this paper, the accuracy of the reconstruction of the 3D point cloud can be increased by increasing the diversity of information through randomness without additional shooting information. In order to objectively evaluate the performance of the proposed method, using the ShapeNet dataset and using the same method as in the comparative papers, the CD value of the method proposed in this paper is 5.87, the EMD value is 5.81, and the FLOPs value is 2.9G. It was calculated. On the other hand, the lower the CD and EMD values, the better the accuracy of the reconstructed 3D point cloud approaches the original. In addition, the lower the number of FLOPs, the less memory is required for the deep learning network. Therefore, the CD, EMD, and FLOPs performance evaluation results of the proposed method showed about 27% improvement in memory and 6.3% in terms of accuracy compared to the methods in other papers, demonstrating objective performance.

컨테이너 하역작업 시 갠트리 크레인의 유연다물체 동역학 모델링 및 윤하중 해석

김정윤,김진곤,Kim, Jungyun,Kim, Jingon 한국전산구조공학회 2014 한국전산구조공학회논문집 Vol.27 No.5

This article describes the dynamic behaviors of a rubber tired gantry crane(RTGC) under typical load conditions which are used in the design of gantry cranes. In order to investigate the dynamic characteristics of an RTGC, we developed a finite element crane model for its huge structure. The finite element model was validated with the modal test results, e.g., natural frequencies and normal modes. And other components of RTGC were converted into detailed 3D CAD models and finally transformed to rigid body models in a dynamic simulation program ADAMS. The load conditions considered in this paper were a normal operating condition(OP1) and container hanging condition with no external loads. As a result, we could find there was large influence of crane's vibration owing to its structural stiffness and deformation. And the vibration of crane could made the movements of RTGC, which occurs crash or malfunction of crane works. 본 논문은 갠트리 크레인의 설계를 위해 컨테이너 하역작업 시 특정하중 조건하의 RTGC(Rubber Tired Gantry Crane)의 동적거동과 그에 따른 윤하중을 분석한 내용을 기술하고 있다. 먼저 RTGC의 동적거동을 살펴보기 위해 거대 구조물인 크레인의 유한요소 모델을 개발하고 고유진동수와 고유모드의 모달시험결과를 이용하여 유한요소모델을 검증하였다. RTGC의 기타 부속품은 3차원 CAD모델링을 통해 다물체 동역학해석 소프트웨어인 ADAMS에서 강체로 모델링하였다. 본 연구에서 하중 조건은 일반적인 컨테이너의 이송조건(OP1)과 외부부하조건 없이 단순히 트롤리를 이용하여 컨테이너를 하역하는 2가지 경우로 고려하였다. 해석 결과 RTGC의 컨테이너 작업 시 발생하는 크레인의 진동은 거대 구조물의 강성과 변형에 주로 기인함을 확인하였으며 이러한 크레인의 진동은 RTGC의 움직임을 발생시켜 컨테이너 하역작업 불능 등의 거동을 발생시킬 수 있음을 분석할 수 있었다.

IP기반의 Pay-TV 시스템을 위한 안전하고 효율적인 그룹 키 분배 프로토콜

김정윤,최형기,Kim, Jung-Yoon,Choi, Hyoung-Kee 한국정보처리학회 2009 정보처리학회논문지 C : 정보통신,정보보안 Vol.16 No.2

최근 몇 년간, IP-TV 등 IP 기반의 방송 서비스들이 급속도로 보급되고 있다. 이러한 IP기반의 Pay-TV 서비스들은 미디어 컨텐츠를 보호하기 위한 보안 시스템을 필요로 한다. 본 논문은 IP기반의 Pay-TV 보안 시스템인 Conditional Access System을 분석하고, 현재의 Conditional Access System이 비효율적인 방식으로 그룹 키를 분배한다는 사실을 제시한다. 본 논문은 Conditional Access System의 성능을 향상시키기 위해서, 안전하고 효율적인 그룹 키 분배 프로토콜을 제안한다. 본 논문에서 제안하는 프로토콜은 간단한 사칙연산 만으로 그룹 키의 분배가 가능하다. 성능 분석 결과는 본 논문에서 제안하는 프로토콜이 Conditional Access System보다 효율적이라는 것을 보여준다. 뿐만아니라, 본 논문에서 제안하는 프로토콜에서는 그룹 키를 분배하는 과정에서 서버와 단말 둘만이 공유하게 되는 비밀 값을 쉽게 획득할 수 있다. 이 비밀 값은 서버와 단말이 공유하고 있는 마스터 키를 대체할 수 있으며, 이는 마스터 키의 반복된 사용에 의해 발생되는 공격들로부터 시스템을 안전하게 보호한다. Recently,IP-based broadcasting systems,such as Mobile-TV and IP-TV, have been widely deployed. These systems require a security system to allow only authorized subscribers access to broadcasting services. We analyzed the Conditional Access System, which is a security system used in the IP-based Pay-TV systems. A weakness of the system is that it does not scale well when the system experiences frequent membership changes. In this paper, we propose a group key distribution protocol which overcomes the scalability problem by reducing communication and computation overheads without loss of security strength. Our experimental results show that computation delay of the proposed protocol is smaller than one of the Conditional Access System. This is attributed to the fact that the proposed protocol replaces expensive encryption and decryption with relatively inexpensive arithmetic operations. In addition, the proposed protocol can help to set up a secure channel between a server and a client with the minimum additional overhead.

레드비트의 생리활성

김정윤,김현구,Kim, Jung-Yun,Kim, Hyun-Ku 한국식품연구원 2009 食品技術 Vol.22 No.3

서비스 고도화를 위한 차세대 네트워크의 형상 분석

김정윤,이경휴,김성연,박권철,Kim, J.Y.,Lee, K.H.,Kim, S.Y.,PArk, K.C. 한국전자통신연구원 2003 전자통신동향분석 Vol.18 No.3

IP 전화 기술의 발전과 서비스 보급이 확대됨에 따라서 통신사업자는 투자 및 운용 비용을 절감하고 기존수입의 보전은 물론 신규 수익을 창출하기 위한 방안으로 서비스 고도화가 가능한 차세대 네트워크를 구축하기 위한 계획을 수립하고 있다. 본 문서는 차세대 네트워크의 핵심 구성 요소인 소프트스위치, 미디어 게이트웨이, 응용 서버, 그리고 미디어 서버의 정의, 기능을 분석하여 그 역할을 정립한다. 즉, 차세대네트워크의 형상을 분석하여 구성 요소의 역할과 인터페이스를 명확히 정의하고자 한다. 특히 고도 서비스를 제공하기 위한 필수 요소인 응용 서버와 미디어 서버에 대하여 중점적으로 분석하고, 두 구성 요소의 상호작용을 정의한다. 차세대 네트워크 형상의 분석 결과는 통신 사업자가 성공적으로 고도 서비스를 제공하여 기존 수입을 보전하고 신규 수익을 창출할 수 있는 차세대 네트워크를 구축하기 위하여 필요한 전략 수립 자료로 활용될 것이다.

체험 마케팅 요소를 활용한 주택문화관의 디자인 방향

김정윤,이현수,이주현,Kim, Jung-Yoon,Lee, Hyun-Soo,Lee, Ju-Hyun 한국주거학회 2007 한국주거학회 논문집 Vol.18 No.5

The purpose of this study is an analysis about space of housing cultural center with the marketing based on experience. By changing housing market, housing cultural center is a place to give an information, added value, image of housing. Consumers who experience a housing cultural center have an effect on purchase an apartment. The image of enterprise is important to select commodities to consumers. Today, company's brand image and concept include womanish, worthy and, sensual those. Under these views, housing cultural center should have continuous culture spaces that provide various experiential chance for consumers. The methods of this study are an analysis of brand image, analysis and application of experiential elements for housing cultural center. The results of this study have five parts. First, in Sense part, there are presented the sense of sight, smell and touch include material's color, finishing material, sound and etc. Second, in Feel part, consumers feel friendly and comfortable to brand through synesthesia. And they have a liberal mind about brand. Third, in Think part, consumers can experience a brand's image as a subject of event or space. Forth, in Act part, consumer is acted to scale of a space and aim of exhibition. Finally, in Relation part, consumers can have relation each other who visit Housing cultural center. And they can joint for interchange of information, culture enjoyment. In conclusion, this study has a great value of graft marketing view on the planning of Housing cultural center.

NPD (New Product Development) Structural Features for Successful Product Proliferation

김정윤,한주희,Kim, Jung-Yoon,Hahn, Ju-Hee The Korea Academia-Industrial cooperation Society 2009 한국산학기술학회논문지 Vol.10 No.11

본 연구는 성공적으로 제품 다양성을 증가시키기 위한 신제품 개발 조직의 특성을 분석하는 데 있다. 본 연구는 플랫폼 및 파생제품 개발을 위한 조직의 구조적 특성을 개별적으로 고려하여, 제품군 (product family) 전체의 성과에 미치는 영향을 분석하고자 한다. 본 연구에서는, 조직 내 구성원 및 그룹간의 관계를 규정짓는 3가지 요인(분권화, 공식화, 전문화)과 함께, 개발 관련 조직 간 공간적 근접성 (spatial proximity)을 조직의 구조적 특성을 파악하는 요인으로 사용하고자 한다. 본 연구는 국내 103개 제조업체로부터 수집한 설문응답 분석에 기초하였다. 조직 구조적 특성은 기업의 제품 다양성 정도와 신제품 개발 성과 간의 관계를 매개하는 것으로 나타났다. 특히 본 연구결과는 기존 신제품 개발 조직 연구와 상반되는 몇 가지 결과를 보고 주고 있다. 제품 다양성을 증가시키는 기업에게 있어, 플랫폼 제품 개발 과정의 공식화 및 파생 제품 개발과정의 분권화는 제품군 전체의 성과를 향상시켜 준다. 본 연구는 개발 조직의 공간적 근접성이 성공적으로 제품 다양성을 증가시키는 데 중요한 조직요소라는 것을 증명하였다. The aim of the current study is to look at the mediating effects of structural features (i.e. decentralization, formalization, and specialization) on the relationship between product variety and the performance of product family. This study investigates the impact of decentralization and formalization for platform and derivative projects separately and in the context of the performance of the product family as a whole, as opposed to individual projects. In addition to relationships between people and groups, the current study considers physical element of an organization such as geographical location in which business tasks are conducted. The current study focuses on spatial differentiation which refers to the number of different sites or locations operated by an organization. Based on a cross-industry sample of 103 Korean manufacturers, this study examines the role of organizational structure features in which firms successfully increase product variety. The study examines that formalization in platform projects and decentralization in derivative projects enhance high variety firms' product family performance. The study finds significant mediating effect of spatial proximity on the relationship between product variety and product family performance.

대만 치치 지진 메모리얼 - 접근과 설계과정 -

김정윤,Kim Jungyoon 한국조경학회 2004 韓國造景學會誌 Vol.32 No.5

Cherishing the dead is based in sadness. Designing a memorial space therefore has an inherent challenge to evoke the feeling that is so personal and varied by providing a physical space. The tendency of memorials, especially in the US after the mid 20th century, has been to emphasis each dead individual, as seen at the Vietnam Veterans Memorial in Washington, D. C., the Oklahoma City National Memorial in Oklahoma City, and so forth. In the process of designing the memorial of the Taiwanese Chi-chi earth-quake, Cheng Kim Park Robidoux tried to set up a series of spaces through which not only the relatives of the dead but also unrelated visitors could have their own spatial experiences, private rituals and public events, so that they can finally build up a collective memory. Sky-Well consists of a large bamboo forest enclosing a void. Without a particular entrance and guiding system, visitors stroll and get lost in the bamboo forest before they find the central void. The horror they experienced during the earthquake is melted down into the motion and phenomenology of the bamboo forest whereas the central void is reinterpreted as an empty mind, where people find solace from the sky. Details, such as the bamboo wall to place commemorative flowers and lotus blossom paving, are echoing the theme of rebirth.