• Title/Summary/Keyword: 시스템 해석

Search Result 9,994, Processing Time 0.043 seconds

A Study on the Optimization of Main Dimensions of a Ship by Design Search Techniques based on the AI (AI 기반 설계 탐색 기법을 통한 선박의 주요 치수 최적화)

  • Dong-Woo Park;Inseob Kim
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.28 no.7
    • /
    • pp.1231-1237
    • /
    • 2022
  • In the present study, the optimization of the main particulars of a ship using AI-based design search techniques was investigated. For the design search techniques, the SHERPA algorithm by HEEDS was applied, and CFD analysis using STAR-CCM+ was applied for the calculation of resistance performance. Main particulars were automatically transformed by modifying the main particulars of the ship at the stage of preprocessing using JAVA script and Python. Small catamaran was chosen for the present study, and the main dimensions of the length, breadth, draft of demi-hull, and distance between demi-hulls were considered as design variables. Total resistance was considered as an objective function, and the range of displaced volume considering the arrangement of the outfitting system was chosen as the constraint. As a result, the changes in the individual design variables were within ±5%, and the total resistance of the optimized hull form was decreased by 11% compared with that of the existing hull form. Throughout the present study, the resistance performance of small catamaran could be improved by the optimization of the main dimensions without direct modification of the hull shape. In addition, the application of optimization using design search techniques is expected for the improvement in the resistance performance of a ship.

A Study on Establishing a Market Entry Strategy for the Satellite Industry Using Future Signal Detection Techniques (미래신호 탐지 기법을 활용한 위성산업 시장의 진입 전략 수립 연구)

  • Sehyoung Kim;Jaehyeong Park;Hansol Lee;Juyoung Kang
    • Journal of Intelligence and Information Systems
    • /
    • v.29 no.3
    • /
    • pp.249-265
    • /
    • 2023
  • Recently, the satellite industry has been paying attention to the private-led 'New Space' paradigm, which is a departure from the traditional government-led industry. The space industry, which is considered to be the next food industry, is still receiving relatively little attention in Korea compared to the global market. Therefore, the purpose of this study is to explore future signals that can help determine the market entry strategies of private companies in the domestic satellite industry. To this end, this study utilizes the theoretical background of future signal theory and the Keyword Portfolio Map method to analyze keyword potential in patent document data based on keyword growth rate and keyword occurrence frequency. In addition, news data was collected to categorize future signals into first symptom and early information, respectively. This is utilized as an interpretive indicator of how the keywords reveal their actual potential outside of patent documents. This study describes the process of data collection and analysis to explore future signals and traces the evolution of each keyword in the collected documents from a weak signal to a strong signal by specifically visualizing how it can be used through the visualization of keyword maps. The process of this research can contribute to the methodological contribution and expansion of the scope of existing research on future signals, and the results can contribute to the establishment of new industry planning and research directions in the satellite industry.

A Study on the Environment of Storytelling Based on the History of Japanese Imperialism and Its Problems and Improvements - Around the Militia, Assassination, The Battleship Island, Anarchist from Colony, Dongju and Princess Deokhye - (일제강점기 역사 서사를 중심으로 한 스토리텔링의 환경과 그에 따른 문제점과 개선 방안 연구 - 밀정, 암살, 박열, 동주, 군함도 그리고 덕혜옹주 중심으로 -)

  • Jin, Seung-Hyeon
    • Journal of Korea Entertainment Industry Association
    • /
    • v.13 no.1
    • /
    • pp.1-9
    • /
    • 2019
  • In this paper, it is predicted that the tendency of planning and genre films to produce high - quality films will continue, but it is necessary to have high value and meaningful films and solid storytelling. From the blockbuster warships to arts and low-budget films, the movie genre is centered around fiction and storytelling. However, in the case of Princess Deokhye, it is difficult to recognize any categories of entertainment or artistic due to the fact that it is highly visually and has a high historical status and low awareness. And the distortions of the facts have caused a lot of controversy. However, it seems that Dongju and Park are usually composed of individual - oriented narratives and can be freed from the artistic approach and historical facts in the material. In addition, historical facts should not be distorted or exaggerated. Through this study,

Study on Radionuclide Migration Modelling for a Single Fracture in Geologic Medium : Characteristics of Hydrodynamic Dispersion Diffusion Model and Channeling Dispersion Diffusion Model (단일균열 핵종이동모델에 관한 연구 -수리분산확산모델과 국부통로확산모델의 특성-)

  • Keum, D.K.;Cho, W.J.;Hahn, P.S.;Park, H.H.
    • Nuclear Engineering and Technology
    • /
    • v.26 no.3
    • /
    • pp.401-410
    • /
    • 1994
  • Validation study of two radionuclide migration models for single fracture developed in geologic medium the hydrodynamic dispersion diffusion model(HDDM) and the channeling dispersion diffusion model(CDDM), was studied by migration experiment of tracers through an artificial granite fracture on the labolatory scale. The tracers used were Uranine and Sodium lignosulfonate know as nonsorbing material. The flow rate ranged 0.4 to 1.5 cc/min. Related parameters for the models were estimated by optimization technique. Theoretical breakthrough curves with experimental data were compared. In the experiment, it was deduced that the surface sorption for both tracers did not play an important role while the diffusion of Uranine into the rock matrix turned out to be an important mass transfer mechanism. The parameter characterizing the rock matrix diffusion of each model agreed well The simulated result showed that the amount of flow rate could not tell the CDDM from the HDDM quantitatively. On the other hand, the variation of fracture length gave influence on the two models in a different degree. The dispersivity of breakthrough curve of the CDDM was more amplified than that of the CDDM when the fracture length was increased. A good agreement between the models and experimental data gave a confirmation that both models were very useful in predicting the migration system through a single fracture.

  • PDF

Effect of Latent Heat Material Placement on Inside Temperature Uniformity of Insulated Transfer Boxes (단열용기의 잠열재 배치에 따른 내부 온도 균일성에 대한 영향)

  • HyungYong Ji;Dong-Yeol Chung;Seuk Cheun Choi;Joeng-Yeol Kim
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
    • /
    • v.29 no.1
    • /
    • pp.27-33
    • /
    • 2023
  • An optimized design of the transportation insulated box must be considered to control the thermal damage in order to maintain the fresh condition for temperature-sensitive medicine and frozen food safety. The inside temperature of the insulated box is a natural convection enclosure state, thermal stratification naturally occurs as time passes in case of with outside heat load. The latent heat material (LHM) placement inside the box maintains the target temperature of the product for temperature fluctuations during transport, and LHM application is a common and efficient method. In this work, inside temperature stratification in an insulated box depending on the LHM pack position is numerically simulated and experimented. The insulated box is made up of vacuum insulation panel (VIP), and LHM modules are placed over six faces inside the box, with the same weight. The temperature curves for 72 hrs as experiment results clearly show the temperature stratification in the upper, middle, and lower at the LHM melting time region. However, the temperature stratification state is uniformly changed in accordance with the condition of the upper and lower placement weight of the LHM pack. And also, the temperature uniformity by changed placement weight of LHM has an effect on maintaining time for target air temperature inside the box. These results provide information on the optimized design of the insulated box with LHM.

Case study of Lighting method to improve TV news viewers' attention span -Based on KBS News 9 Lighting Method Analysis- (TV뉴스 시청자의 집중도 향상을 위한 조명 기법의 사례 연구 -KBS 9시 뉴스 조명 기법 분석을 중심으로-)

  • Han, Hak-Soo
    • Journal of the Korea Society of Computer and Information
    • /
    • v.14 no.12
    • /
    • pp.97-107
    • /
    • 2009
  • Television News has significant impact on the information analysis of viewers by delivering world news to anonymous individuals everyday. We need to pay more attention to resolution considering the fact that even slight facial expression and the dress of TV anchor can be noticed by viewers in the high definition age, called HD TV, by radical changes in broadcasting situation. As a result, the beauty of expression that lighting technology has is extremely important in the high definition age. In news broadcast, as a phenomenon according to this change in trend, people have been looking for change in order to break with traditional TV news production by adopting DLP(Digital Lighting Processing) or LED(Light Emitting Diode). This effort has contributed to creating proper picture quality appropriate for HD TV. Nowadays Digital imaging is creating new trend in TV news production method from traditional analog-based lighting environment thanks to the development of IT(Information Technology) and digitalized lighting equipment. This change has led to building of HD studio and appropriate sets and lighting system. There are film set and projector which projects image on the screen and PDP, LCD, and DLP which has been used widely in recent years and LED which is often used as background in news program as examples, which has appeared since 1990s with HD TV. In this article, I analyzed the KBS News 9 lnce 1990s with in order to research the influence of television image component on the alyzed the KBS of TV article, I. I wille uggest the category of TV anchor image formulation in delivering information by means of lnce 1990s with based on the analysis result.

Development of an IMU-based Wearable Ankle Device for Military Motion Recognition (군사 동작 인식을 위한 IMU 기반 발목형 웨어러블 디바이스 개발)

  • Byeongjun Jang;Jeonghoun Cho;Dohyeon Kim;Kyeong-Won Park
    • Journal of Intelligence and Information Systems
    • /
    • v.29 no.2
    • /
    • pp.23-34
    • /
    • 2023
  • Wearable technology for military applications has received considerable attention as a means of personal status check and monitoring. Among many, an implementation to recognize specific motion states of a human is promising in that allows active management of troops by immediately collecting the operational status and movement status of individual soldiers. In this study, as an extension of military wearable application research, a new ankle wearable device is proposed that can glean the information of a soldier on the battlefield on which action he/she takes in which environment. Presuming a virtual situation, the soldier's upper limbs are easily exposed to uncertainties about circumstances. Therefore, a sensing module is attached to the ankle of the soldier that may always interact with the ground. The obtained data comprises 3-axis accelerations and 3-axis rotational velocities, which cannot be interpreted by hand-made algorithms. In this study, to discern the behavioral characteristics of a human using these dynamic data, a data-driven model is introduced; four features extracted from sliced data (minimum, maximum, mean, and standard deviation) are utilized as an input of the model to learn and classify eight primary military movements (Sitting, Standing, Walking, Running, Ascending, Descending, Low Crawl, and High Crawl). As a result, the proposed device could recognize a movement status of a solider with 95.16% accuracy in an arbitrary test situation. This research is meaningful since an effective way of motion recognition has been introduced that can be furtherly extended to various military applications by incorporating wearable technology and artificial intelligence.

Explainable Artificial Intelligence Applied in Deep Learning for Review Helpfulness Prediction (XAI 기법을 이용한 리뷰 유용성 예측 결과 설명에 관한 연구)

  • Dongyeop Ryu;Xinzhe Li;Jaekyeong Kim
    • Journal of Intelligence and Information Systems
    • /
    • v.29 no.2
    • /
    • pp.35-56
    • /
    • 2023
  • With the development of information and communication technology, numerous reviews are continuously posted on websites, which causes information overload problems. Therefore, users face difficulty in exploring reviews for their decision-making. To solve such a problem, many studies on review helpfulness prediction have been actively conducted to provide users with helpful and reliable reviews. Existing studies predict review helpfulness mainly based on the features included in the review. However, such studies disable providing the reason why predicted reviews are helpful. Therefore, this study aims to propose a methodology for applying eXplainable Artificial Intelligence (XAI) techniques in review helpfulness prediction to address such a limitation. This study uses restaurant reviews collected from Yelp.com to compare the prediction performance of six models widely used in previous studies. Next, we propose an explainable review helpfulness prediction model by applying the XAI technique to the model with the best prediction performance. Therefore, the methodology proposed in this study can recommend helpful reviews in the user's purchasing decision-making process and provide the interpretation of why such predicted reviews are helpful.

A Study on Robust Optimal Sensor Placement for Real-time Monitoring of Containment Buildings in Nuclear Power Plants (원전 격납 건물의 실시간 모니터링을 위한 강건한 최적 센서배치 연구)

  • Chanwoo Lee;Youjin Kim;Hyung-jo Jung
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.36 no.3
    • /
    • pp.155-163
    • /
    • 2023
  • Real-time monitoring technology is critical for ensuring the safety and reliability of nuclear power plant structures. However, the current seismic monitoring system has limited system identification capabilities such as modal parameter estimation. To obtain global behavior data and dynamic characteristics, multiple sensors must be optimally placed. Although several studies on optimal sensor placement have been conducted, they have primarily focused on civil and mechanical structures. Nuclear power plant structures require robust signals, even at low signal-to-noise ratios, and the robustness of each mode must be assessed separately. This is because the mode contributions of nuclear power plant containment buildings are concentrated in low-order modes. Therefore, this study proposes an optimal sensor placement methodology that can evaluate robustness against noise and the effects of each mode. Indicators, such as auto modal assurance criterion (MAC), cross MAC, and mode shape distribution by node were analyzed, and the suitability of the methodology was verified through numerical analysis.

Detection of Steel Ribs in Tunnel GPR Images Based on YOLO Algorithm (YOLO 알고리즘을 활용한 터널 GPR 이미지 내 강지보재 탐지)

  • Bae, Byongkyu;Ahn, Jaehun;Jung, Hyunjun;Yoo, Chang Kyoon
    • Journal of the Korean Geotechnical Society
    • /
    • v.39 no.7
    • /
    • pp.31-37
    • /
    • 2023
  • Since tunnels are built underground, it is impossible to check visually the location and degree of deterioration of steel ribs. Therefore, in tunnel maintenance, GPR images are generally used to detect steel ribs. While research on GPR image analysis employing artificial neural networks has primarily focused on detecting underground pipes and road damage, there have been limited applications for analyzing tunnel GPR data, specifically for steel rib detection, both internationally and domestically. In this study, a one-step object detection algorithm called YOLO, based on a convolutional neural network, was utilized to automate the localization of steel ribs using GPR data. The performance of the algorithm is then analyzed. Two datasets were employed for the analysis. A dataset comprising 512 original images and another dataset consisting of 2,048 augmented images. The omission rate, which represents the ratio of undetected steel ribs to the total number of steel ribs, was 0.38% for the model using the augmented data, whereas the omission rate for the model using only the original data was 7.18%. Thus, from an automation standpoint, it is more practical to employ an augmented dataset.