• International Journal of Naval Architecture and Ocean Engineering
• /
• v.12 no.1
• /
• pp.578-595
• /
• 2020

Submarine pressure hulls must withstand high hydraulic pressure and be free of defects. To improve the precision of defect detection, we herein examined different probes for optimal defect assessment by applying the Phased Array Ultrasonic Testing (PAUT) method. Two sets of probe design parameters were selected by considering pressure hull characteristics and analyzed through modeling. PAUT probes were applied, and defect assessment results were compared based on ultrasonic signals of various simulated defects in specimens designed to be the same as actual pressure hulls. The final selected design parameters for the submarine probe, which were designed to minimize the grating lobe of wave interference effect and improve the ultrasonic resolution of pressure hull welds, were identified through the experiment. The improvement in the probe's ability to detect defects in a pressure hull was verified. Furthermore, the accuracy of defect length measurement was improved, enhancing the applicability of the technique.

• International Journal of Advanced Culture Technology
• /
• v.11 no.4
• /
• pp.385-392
• /
• 2023

The smart tourism service provides tourists with personal travel planner services and context-awareness-based tour guide services. In this paper, we propose the personal travel planner service that creates my travel itinerary using the smart tourism app and the travel planner system. The smart tourism app provides recommended travel products and POI tourist information used to create my travel itinerary. The smart tourism app also provides the smart tourism chatbot service that allows users to select POI tourist information easily and conveniently. The travel planner system consists of the smart tourism information system and the smart tourism chatbot system. The smart tourism information system provides users with travel planner services, recommended travel products, and POI tourism information through the smart tourism app. The smart tourism chatbot system consists of named entity recognition (NER), dialogue state tracking (DST), and Neo4J servers, and provides chatbot services as a smart tourism app. Users can create their own travel itinerary, modify the travel itinerary while traveling, and then register it as a recommended travel product to users, including acquaintances.

• Journal of the Korean earth science society
• /
• v.31 no.1
• /
• pp.51-62
• /
• 2010

The purpose of this study was to investigate how a science magazine played a role in filling the gap between scientists and the general public, and how it contributed to science popularization. We analyzed the linguistic features of the texts used in a science magazine. We used 12 articles (six written by journalists, and six written by scientists) from the Science Donga. Register analysis was conducted in order to define the linguistic features of the texts in terms of ideational meaning, interpersonal meaning and, textual meaning. Results of this study are as follows: (1) the articles written by journalists used a higher mental and verbal processes in which the conversations and thoughts of scientists were expressed. (2) Human agents were relatively explicit in the journalists' articles. However, they were implicit or omitted in the articles of scientists. (3) Interrogative sentences and inclusive imperative sentences, and even omissions were frequently found in the journalists' articles whereas scientists' articles mainly used declarative statements. (4) The clause density of journalist' articles and scientists' were similarly lower than that of science textbooks. (5) The information structure revealed by the patterns of Theme and Rheme that the journalists' articles used in science magazines was simpler than that of science textbooks, while the structure of scientists' articles was more complex than that of journalists'. Based on the linguistic features of the texts used in science magazines, we found that a science magazine contributes to science popularization in two faces: One is in that the articles of journalists present science contents in a way that the readers can follow with ease and feel well-acquainted. The other is that the modified articles of scientists help the general public get familiar with the culuture of science in terms of use of science language.

• Korean Journal of Computational Design and Engineering
• /
• v.20 no.2
• /
• pp.193-209
• /
• 2015

For reasons such as global warming, depletion of fossil fuels and the danger of nuclear energy the research and development of renewable energy is actively underway. Wind energy has advantages over another renewable energy in terms of location requirements, energy efficiency and reliability. Nowadays the research and development area is expanded to offshore because it can supply more wind reliability and free from noise pollution. In this study, the monopile offshore wind turbine transportation and installation (T&I) process are investigated. In addition, the schedule and cost for the process are estimated by discrete event simulation. For the simulation, simulation models for various means of T&I are developed. The optimum T&I execution plan with shortest duration and lowest cost can be found by using different mission start day and T&I means.

• Journal of the Society of Naval Architects of Korea
• /
• v.47 no.4
• /
• pp.598-605
• /
• 2010

The structural design of oil tankers and bulk carriers should be performed based on the Common Structural Rules(CSR) which were recently established by the International Association Classification Societies(IACS). At first, in the structural design viewpoint, the scantling and hullweight based on the CSR should be compared with those of existing rules, and then a minimum weight/cost design should be performed by considering the variation of the number of web and the material property. In this study, the optimum web space and material property will be proposed by performing a minimum weight/cost design of a large oil tanker, and the results will be compared with those of existing ship. The longitudinal members are determined by SeaTrust-Holdan developed by the Korean Register of Shipping(KR), and the transverse members are determined by NASTRAN and PULS.

• International Journal of Naval Architecture and Ocean Engineering
• /
• v.2 no.4
• /
• pp.200-210
• /
• 2010

In this paper, different evaluation methods of Hot Spot Stresses (HSS) have been applied to four different welded structure details in order to compare them and to illustrate their differences. The HSSs at failure-critical locations were calculated by means of a series of finite element analyses. There was good overall agreement between calculated and experimentally determined HSS on the critical locations. While different methods and procedures exist for the computation of the structural hot-spot stress at welded joints, the recommendations within the International Institute of Welding (IIW) guideline concerning the 'Hot Spot Stress' approach were found to give good reference stress approximations for fatigue-loaded welded joints. This paper recommends and suggests an appropriate finite element modeling and hot spot stress evaluation technique based on round-robin stress analyses and experimental results of several welded structure details.

• Journal of Fisheries and Marine Sciences Education
• /
• v.28 no.3
• /
• pp.790-798
• /
• 2016

Currently, web-based online games is becoming popular in supporting learning process due to their effective and efficient tool. However, online games have lack of security aspect, in particular due to increase in the number of personal information leakage. Since the data are transmitted over insecure channel, it will be vulnerable of being intercepted by attackers who want to exploit user's identity. This paper aims to propose an online web-based educational game, Vidyanusa which allows the students to register their personal information using a unique code, a user name and a password. It manages the users according to their schools, subject teachers and class levels. In addition, by adopting a unique code, the confidentiality of the user identity can be kept away from attackers. Moreover, in order to provide a secure data communication between client and server, Secure Socket Layer (SSL) protocol is adopted. The performance of the system after implementing SSL protocol is examined by loading a number of requests for various users. From the experiment result, it can be concluded that the SSL protocol can be applied to web-based educational system in order to offer security services and reliable connection.

• Annual Conference on Human and Language Technology
• /
• 1994.11a
• /
• pp.253-258
• /
• 1994

이 글에서 살펴본 바는 다음과 같다. 1) ISO 10646-1 한글 부호계의 운용 방안은, 앞으로 얼마동안은 2,350 완성형 소리마디를 쓸 수도 있겠지만, 길게 보아서는 첫가끝 부호계 238 글자로 통일하는 것이 바람직하다고 본다. 2) ISO 2022 틀을 따르면서 한글을 완벽하계 지원하는 한 바이트 한글 부호계를 개발하여, 국제 등록부 (International Register) 에 등록하여, Escape Sequence을 받아서, ISO 2022 를 따르는 분야에서 쓸 수 있도록 하여야하겠다. 3) ISO 10646-1 을 개정하여 4,516 소리마디를 넣자는 안은, 완성형으로만 한글을 지원하게 되어 바람직하지 않다고 본다. 모아쓰기 글자를 지원하는 세계 추세가 조합방식이므로, 10646-1 을 현재대로 두고, 첫가끝 방식의 238 글자를 쓰는 것이 바람직하다고 본다. 4) 10646-1 을 재대로 지원할 수 있는 세벌식 자판을 정부의 복수 표준으로 채택할 것을 제안한다.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.19 no.7
• /
• pp.22-34
• /
• 2020

Three-dimensional (3D) computer-aided design (CAD) models require different levels of detail (LODs) depending on their purpose. Therefore, it is beneficial to automatically simplify 3D CAD assembly models to meet the desired LOD. Feature-based 3D CAD assembly models typically have the lowest and highest feasible limits of LOD during simplification. In order to help users obtain a feasible simplification result, we propose a method to simplify feature-based 3D CAD assembly models by determining the lowest and highest limits of LOD. The proposed method is verified through experiments using a simplification prototype implemented as a plug-in type module on Siemens NX.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.43 no.3
• /
• pp.73-79
• /
• 2011

The annals of Joseon Dynasty is one of the UNESCO's Memory of the World Register. For the safety preservation of wax applied volumes of the annals of Joseon Dynasty, the aging behavior of beeswax and beeswaxed Hanji with $CO_2$, $O_3$, $SO_2$ and $NO_2$ gas has been evaluated. The weight loss of beeswaxed Hanji after aging under ozone gas were increased because of strong acidity of ozone. The acid value and relative intensity of carbonyl groups in beeswax were stabilized with aging time. The physical strength of dewaxed Hanji after ozone aging were rapidly decreased by aging time. The crystallinity of dewaxed Hanji were stabilized at all aging times.