• Journal of Communications and Networks
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• 제13권2호
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• pp.132-141
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• 2011

IEEE 802.15.4 networks are a feasible platform candidate for connecting all health-care-related equipment dispersed across a hospital room to collect critical time-sensitive data about patient health state, such as the heart rate and blood pressure. To meet the quality of service requirements of health-care systems, this paper proposes a multi-priority queue system that differentiates between various types of frames. The effect of the proposed system on the average delay and throughput is explored herein. By employing different contention window parameters, as in IEEE 802.11e, this multi-queue system prioritizes frames on the basis of priority classes. Performance under both saturated and unsaturated traffic conditions was evaluated using a novel analytical model that comprehensively integrates two legacy models for 802.15.4 and 802.11e. To improve the accuracy, our model also accommodates the transmission retries and deferment algorithms that significantly affect the performance of IEEE 802.15.4. The multi-queue scheme is predicted to separate the average delay and throughput of two different classes by up to 48.4% and 46%, respectively, without wasting bandwidth. These outcomes imply that the multi-queue system should be employed in health-care systems for prompt allocation of synchronous channels and faster delivery of urgent information. The simulation results validate these model's predictions with a maximum deviation of 7.6%.

• Advances in robotics research
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• 제2권1호
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• pp.69-97
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• 2018

Innovation is considered as key to ensure continuous advancement and firm progress in any field. Robotics, with no exception, has gained triumph and approval based on its strength to address divers range of applications as well as its capacity to adapt new ways and means to enhance its applicability. The core of novelty in robotics technology is the perpetual curiosity of human beings to imitate natural systems. This desire urges to continuously explore and find new feet. In the past, contemporary machines, in different shapes, sizes and capabilities, were developed that can perform variety of tasks. The major advantage of these developments was the ability to exhibit superior control, strength and repeatability than the corresponding systems they were replicating. However, these systems were rigid and composed of hard an underlying structure, which is a constraint in bringing into being the compliance that exists in natural organisms. Inspiration of achieving such compliance and to take the full advantage of the design scheme of biological systems compelled researchers and scientists to develop systems avoiding conventional rigid structures. This ambition, to produce biological duos, needs soft and more flexible materials and structures to realize innovative robotic systems. This new footpath to craft biological mockups facilitates further to exploit new materials, novel design methodologies and new control techniques. This paper presents an appraisal on such innovative comprehensions, conferring to their design specific importance. This demonstration is potentially useful to prompt the novelty of soft robotics.

• Journal of Positioning, Navigation, and Timing
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• 제3권3호
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• pp.117-122
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• 2014

In CDGPS, ambiguity resolution is determined by the performance of a floating solution, and thus, the performance needs to be improved. In the case of precise positioning at a stationary position, the batch method using multiple measurements is used for the accuracy improvement of a position. The position accuracy performance of a floating solution is outstanding, but it has a problem of high computation cost because all measurements are used. In this study, to improve the floating solution performance of the initial static user in CDGPS, a floating solution method using a recursive filter was implemented. A recursive filter estimates the position solution of the current epoch using the position solution of up to the previous epoch and the pseudorange measurement of the current epoch. The computation cost of the floating solution method using a recursive filter was found to be similar to that of the epoch-by-epoch method. Also, based on actual GPS signals, the floating solution performance was found to be similar to that of the batch method. The floating solution using a recursive filter could significantly improve the performance of the prompt initial position and ambiguity resolution of the initial static user.

• Natural Product Sciences
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• 제26권4호
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• pp.259-267
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• 2020

Snakebite is a severe medical, economic, and social problem across the world, mostly in the tropical and subtropical area. These regions of the globe have typical of the world's venomous snakes present where access to prompt treatment is limited or not available. Snake venom is a complex mixture of toxin proteins like neurotoxin and cardiotoxin, and other enzymes like phospholipase A2 (PLA2), haemorrhaging, transaminase, hyaluronidase, phosphodiesterase, acetylcholinesterase, cytolytic and necrotic toxins. Snake venom shows a wide range of biological effects like anticoagulation or platelet aggregation, hemolysis, hypotension and edema. Phospholipase A2 is the principal constituent of snake venom; it catalyzes the hydrolysis of the sn-2 position of membrane glycerophospholipids to liberate arachidonic acid, which is the precursor of eicosanoids including prostaglandins and leukotrienes. The information regarding the structure and function of the phospholipase A2 enzyme may help in treating the snakebite victims. This review article constitutes a brief description of the structure, types, mechanism occurrence, and tests of phospholipase A2 and role of components of medicinal plants used to inhibit phospholipase A2.

• 대한조선학회논문집
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• 제60권4호
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• pp.288-295
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• 2023

This paper deals with the dynamic simulation method for analysis of driving characteristics of aircraft and towing vehicles (TUG) on carrier vessel in wave motions. For prompt deployment in a short period of time, optimization of the movement of carrier aircraft becomes a major issue. In this regards, strategy studies using real-time simulation technology and optimal decision-making technologies are being conducted. In the present work, the dynamic characteristics of carrier aircraft and TUG connected by towbar or towbarless mechanism were investigated by means of multi-body dynamics model. Meanwhile, for real-time simulation, Dugoff's model of tire loads calculation was adopted. Through comparative analysis it was confirmed that the similarity of results between the multi-body contact model and the tire load calculation model can be achieved by coefficients tuning.

• 지능정보연구
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• 제12권2호
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• pp.33-48
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• 2006

의미 웹(Semantic Web)과 이에 대한 관련기술들은 웹을 통해 자유롭게 정보를 공유할 수 있는 새로운 지평을 마련해 주었다. 이를 토대로 온톨로지(Ontology)에 대한 연구 역시 활발히 진행되어 왔으며, 결과적으로 온톨로지는 여러 가지 측면에서 가시적인 성과들을 이룩해 낼 수 있었다. 의미 웹에 대한 기대가 고조되면서, 온톨로지는 많은 연구 학자들로부터 각광을 받는 분야로 떠오를 수 있었으며, 오늘날, 이러한 온톨로지에 대한 연구는 지식표현Knowledge-Representation)등과 같은 학술적인 단계에서 벗어나 전자상거래 분야까지 그 영역을 넓혀 나가고 있다. 그러나 일부에서는 이러한 온톨로지의 양산으로 인해 발생할 문제들에 대한 우려의 목소리가 적지 않다. 즉, 현재 온톨로지들은 서로간의 이질성으로 인해 그 효용 가치를 위협받고 있다는 것이다. 예를 들어, 현재 Yahoo나 DMOZ Open Directory(www.(dmoz.org)등으로부터 제공 중인 상품 카테고리의 경우, 시각적으로는 유사해 보일지 모르나 그들이 지닌 카테고리 구조라든지 사용된 용어 등을 살펴보면 상당한 차이점이 존재한다는 사실을 발견해 낼 수 있다. 따라서 현재 온톨로지가 지향하는 본래의 효용 가치를 극대화시키기 위해서는 이러한 이질성을 극복할 수 있는 방법론이 반드시 필요하다고 할 수 있다. 본 연구에서는 현재 온톨로지 분야에서 가장 커다란 이슈로 떠오르고 있는 정보통합에 대한 해결책을 제시해 보고자 한다. 정보통합이란, 서로 이질적인 프로그래밍 언어나 형식으로 이루어진 데이터들을 통합하여 요약한 형태로 제공하는 기술이라 정의 내릴 수 있다. 이러한 정보 통합의 대표적인 분야로 Merging, Alignment, Translation, Articulation을 들 수 있는데, 이 가운데, 본 연구에서는 "Ontology Alignment"에 대해 집중적으로 다루어 보고자 한다. 이와 더불어, 현재 의미 웹이 지향하는 대표적인 특성 중 하나로써 상호운영성을 꼽을 수 있다. 온톨로지 매핑(Ontology mapping)은 이러한 상호운영성을 지원하기 위한 대표적인 기술로써 각광을 받고 있다. 따라서 우리는 이러한 온톨로지 매핑에 대한 방법론을 쇼핑몰 환경에 적용함으로써 서로 이질적인 상품 카테고리로 구성된 두 쇼핑몰간의 상품에 대한 매핑 알고리즘(Mapping Algorithm)을 제안하고자 한다. 또한, 효용성 검증을 위하여 온톨로지 매핑에 있어 이미 효용성을 검증 받은 PROMPT와의 비교 분석도 수행하여 본다.

• 문화기술의 융합
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• 제10권2호
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• pp.493-498
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• 2024

최근 생성형 인공지능 기술이 급속도로 발전함에 따라, 이를 실무에 활용하는 방법에 대한 관심이 높아지고 있다. 또한 사용자 요구에 부합하는 결과물을 생성하기 위한 프롬프트 엔지니어링의 중요성이 새롭게 조명되고 있다. 이러한 생성형 인공지능의 새로운 활용 가능성을 탐구하는 것은 중요한 가치를 지닐 수 있다. 본 연구는 대표적인 생성형 인공지능인 챗지피티 4.0을 활용하여 온라인 고객 리뷰 데이터 분석을 통한 효과적인 사용자 경험 평가 방법을 제안하는 것을 목적으로 한다. 사용자 경험 평가 방법은 사용자 경험 계층의 6단계 요소인 '기능성', '신뢰성', '사용성', '편의성', '감성', '의미성'을 기반으로 수행되었다. 본 연구를 위해 프롬프트 엔지니어링의 이해도를 높이고 사용자경험 계층의 명확한 개념을 파악하는 문헌연구를 수행하고, 이를 기반으로 프롬프트를 작성 및 수집된 온라인 고객 리뷰 데이터 분석을 통한 사용자 경험 평가 방법을 위한 실험이 수행되었다. 본 연구에서 우리는 사용자 경험 요소에 대한 정확한 정의 및 분류 과정에 대한 설명 입력 시, 챗지피티는 사용자 경험 평가에 대한 우수한 성능을 나타냈으나, 시간적 제약으로 다량의 데이터 분석에 한계를 나타냈음을 밝힌다. 우리는 사용자 경험 평가에 챗지피티 4.0을 활용하는 방법을 소개하고 제안함으로써 UX 분야의 발전에 공헌할 수 있는 것으로 기대한다.

• Journal of Mechanical Science and Technology
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• 제20권9호
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• pp.1459-1474
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• 2006

The present study is focused on the development of the RIF (Representative Interactive Flamelet) model which can overcome the shortcomings of conventional approach based on the steady flamelet library. Due to the ability for interactively describing the transient behaviors of local flame structures with CFD solver, the RIF model can effectively account for the detailed mechanisms of $NO_x$ formation including thermal NO path, prompt and nitrous $NO_x$ formation, and reburning process by hydrocarbon radical without any ad-hoc procedure. The flamelet time of RIFs within a stationary turbulent flame may be thought to be Lagrangian flight time. In context with the RIF approach, this study adopts the Eulerian Particle Flamelet Model (EPFM) with mutiple flamelets which can realistically account for the spatial inhomogeneity of scalar dissipation rate. In order to systematically evaluate the capability of Eulerian particle flamelet model to predict the precise flame structure and NO formation in the multi-dimensional elliptic flames, two methanol bluffbody flames with two different injection velocities are chosen as the validation cases. Numerical results suggest that the present EPFM model has the predicative capability to realistically capture the essential features of flame structure and $NO_x$ formation in the bluff-body stabilized flames.

• 한국측량학회지
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• 제36권3호
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• pp.177-184
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• 2018

In case that limited resources can be mobilized, non-structural countermeasures such as 'monitoring using Information and Communication Technology might be one of solutions to mitigate disaster risks. Having established the monitoring system, operational and maintenance costs to maximize the effectiveness might trouble the authority concerned or duty attendant who is in charge. In this respect, "Guerrilla Sensor" would be very cost effective because of the inherent mobility characteristic. The sensor device with the IRIS camera and GPS (Global Positioning System) equipped, is basically battery-operated and communicates with WCDMA (Wideband Code Division Multiple Access). It has a strong advantage of capabilities for 'Disaster Response' with immediate and prompt action on the spot, making the best use of IoT (Internet of Things), especially with the mobile web. This paper will explain how the sensor system works in real-time GIS (Geographic Information System) pinpointing the exact location of the abnormal movement/ground displacement and notifying the registered users via SMS (Short Message Service). Real time monitoring with early warning and evaluation of current situations with LBS (Location Based Service), live image and data information can help to reduce the disaster impact. Installation of Guerrilla sensor for a real site application at Gimcheon, South Korea is also reported.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집C
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• pp.213-218
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• 2001

VR (Virtual reality) technologies have given engineers the ability to design, test, and evaluate engineering systems in a virtual environment. The virtual plant is the highlight of the application of the VR technology to plant engineering. Plant design, maintenance, control, management, operation are integrated in the virtual plant. The VR monitoring system including the concept of the virtual plant is developed to replace a current control room that has number of gages and warning lamps in two-dimensional panels which shows the operating status of a plant. The operating status of the plant is displayed in the VR monitoring system through the realistic computer graphics. Sophisticated, realistic and prompt control becomes possible. The VR monitoring system consists of advanced visualization, walk-through simulation and navigation. In the virtual environment, a user can navigate and interact with each component of a plant. In addition, the user can access the information by just clicking interesting component. The VR monitoring system is operated with various modules, such as (1) virtual plant constructed with Graphic Management System (GMS), (2) Touch & Tell System, and (3) Equipment DB System of Part. In order to confirm the usefulness of the VR monitoring system, a pilot gas plant which is currently being used for plant operator training is taken as application. The end of the paper gives an outlook on the future work and a brief conclusion.