• International Journal of Naval Architecture and Ocean Engineering
• /
• 제6권2호
• /
• pp.392-405
• /
• 2014

SSPA experiences a growing interest in twin skeg ships as one attractive green ship solution. The twin skeg concept is well proven with obvious advantages for the design of ships with full hull forms, restricted draft or highly loaded propellers. SSPA has conducted extensive hull optimizations studies of LNG ships of different size based on an extensive hull data base with over 7,000 models tested, including over 400 twin skeg hull forms. Main hull dimensions and different hull concepts such as twin skeg and single screw were of main interest in the studies. In the present paper, one twin skeg and one single screw 170 K LNG ship were designed for optimally selected main dimension parameters. The twin skeg hull was further optimized and evaluated using SHIPFLOW FRIENDSHIP design package by performing parameter variation in order to modify the shape and positions of the skegs. The finally optimized models were then built and tested in order to confirm the lower power demand of twin skeg designed compaed with the signle screw design. This paper is a full description of one of the design developments of a LNG twin skeg hull, from early dimensional parameter study, through design optimization phase towards the confirmation by model tests.

• 비파괴검사학회지
• /
• 제29권6호
• /
• pp.550-556
• /
• 2009

In an application of a time reversal(TR) focusing of array transducer on a defect inside the test material, we employ a new time delay focusing technique based the TR process. In order to realize this idea, a multi-channel ultrasonic system is constructed capable of applying necessary time delays to each channel. The TR-based focusing procedure first measures the backscattered signals after firing one of the array elements. A phase slope method is then used to determine the time-of-flights of the backscattered signals received by all elements of the array. These time delays are used to adjust the time of excitation of the elements for transmission focusing on the defect. In addition to the TR focusing, the classical phased array focusing is also considered for comparison. Experimental results show that the TR-based time delay focusing produces much stronger backscattered signals than the phased array focusing, demonstrating the enhanced capability of the TR focusing.

• 정보교육학회논문지
• /
• 제19권3호
• /
• pp.271-278
• /
• 2015

본 연구에서 알고리즘 능력을 측정하여 정보 영재를 판별할 수 있는 도구를 개발하였다. 판별 도구는 Computational Thinking의 Concept을 재구성하여 해당 영역이 중점적으로 포함되어있는 문항을 제작하였다. 문항의 유형을 단일 속성 문항, 복합 동일 속성 문항, 복합 집중 속성 문항으로 나누어 세분화하였으며 문제 해결방식을 전체 스크립트 제작, 스크립트의 일부 수정, 스크립트의 결과 추측하기로 나누어 스크래치 프로그램으로 개발하였다. 개발한 판별도구를 영재학생들에게 적용한 결과 문항의 타당도와 신뢰도가 높은 것으로 나타났다.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
• /
• pp.98-101
• /
• 2006

As an alternative of conventional prestressed concrete (PSC) girders, various types of PSC girders are being developed and applied in bridge structures. Incrementally prestressed concrete girder is one of these newly developed girders. According to design concept, these new types of PSC girders have considerable advantages to reduce their self-weight and make spans longer. However, dynamic interaction between bridge superstructures and passing trains would be sometimes one of critical issues in these more flexible railway bridges. Therefore, it is very important to evaluate modal parameters of newly designed bridges before conducting dynamic analyses. In the present paper, a 25 meters long full scale PSC girder was fabricated as a test specimen and modal testing was carried out to evaluate modal parameters including natural frequencies and modal damping ratios at every prestressing stage. In the modal testing, a digitally controlled vibration exciter as well as an impact hammer is applied to obtain frequency response functions more exactly and the modal parameters are evaluated varying with construction stages. Prestressed force effects on changes of modal parameters are analyzed at every incremental prestressing stage.

• 한국정보통신학회:학술대회논문집
• /
• 한국해양정보통신학회 2000년도 춘계종합학술대회
• /
• pp.252-256
• /
• 2000

본 논문에서는 수준별 학습을 위한 웹 기반 교육도구를 설계 및 구현 하고자 하였다. 구현한 시스템의 구성은 크게 교사가 사용할 관리자 영역과 학생이 사용할 사용자 영역으로 나누어져 있다. 관리자 영역에서는 학습자의 학습을 도울 수 있도록 하기 위하여 단원별 강의안 등록, 수준별 평가문제의 출제 및 평가를 위한 기능을 제공한다 사용자인 학생은 누구나 사용자 등륵만 하면 사이버스쿨(Cyber shool)에 로긴(Login)하여 자신의 수준에 맞는 학습을 하고, 평가를 받을 수 있다 평가 후에는 즉시 자신의 점수를 확인하고 점수를 따른 보충학습, 또는 심화학습을 할 수 있다. 본 시스템에서는 학습자들에게 수준에 맞는 학습을 제공함으로써 학습의 흥미를 유도하고, 학업 성취도를 향상시키고자 하였다.

• 비파괴검사학회지
• /
• 제19권5호
• /
• pp.340-346
• /
• 1999

액체/고체 경계면에 표면파가 발생할 때 나타나는 최소반사 및 후방복사 현상을 이용하여 brass와 aluminum 시편 그리고 copper/stainless steel, nickel/brass, nickel/aluminum 도금시편에 대한 표면 탄성파 속도의 주파수 의존성이 측정되었다. 측정된 속도의 분산관계는 일반화 램 표면파의 분산 특성과 잘 일치하였다. 시편들의 분산 특징에 따라 최소반사와 후방복사에 의해 결정된 속도 차이의 경향이 다르게 나타났다. 이러한 대응 관계는 두 현상의 생성 메커니즘과 군속도의 도입으로 설명되었다.

• 비파괴검사학회지
• /
• 제35권6호
• /
• pp.389-397
• /
• 2015

Recently, wave propagation imaging based on laser scanning-generated elastic waves has been intensively used for nondestructive inspection. However, the proficiency of the conventional software based system reduces when the scan area is large since the processing time increases significantly due to unavoidable processor multitasking, where computing resources are shared with multiple processes. Hence, the field programmable gate array (FPGA) was introduced for a wave propagation imaging method in order to obtain extreme processing time reduction. An FPGA board was used for the design, implementing post-processing ultrasonic wave propagation imaging (UWPI). The results were compared with the conventional system and considerable improvement was observed, with at least 78% (scanning of $100{\times}100mm^2$ with 0.5 mm interval) to 87.5% (scanning of $200{\times}200mm^2$ with 0.5 mm interval) less processing time, strengthening the claim for the research. This new concept to implement FPGA technology into the UPI system will act as a break-through technology for full-scale automatic inspection.

• The Journal of Asian Finance, Economics and Business
• /
• 제7권7호
• /
• pp.279-291
• /
• 2020

This study aims to develop the concept of innovation models with the marketing channel construct approach, marketing innovation, product segmentation, and customer insight; as well as improvements to the theory of resource-based combined with the method of service-dominant logic. This study approach is based on quantitative descriptive conducted with three stages of testing scenarios. The first test is the mapping of the innovation model construct through testing the validity and reliability with the moderation of customer orientation variables. The second scenario examines the relationship of influence between the independent variables on the dependent variable of 29 hypothetical analysis equation modeling. The unit of analysis was conducted on 497 SMEs involved in the food and beverage sectors, with the criteria being SMEs must have a rating of 4-5 points on the Go-Food applications software. The results shown that: 1) the construct used to develop an innovative model both directly and via moderation is positive and significant; 2) Through a complicated relationship that involves all components of the variable, it outlines a positive and significant effect except for the path of analysis (μ5). The theoretical and managerial implications state that the service-dominant logic approach and resource-based view theory have extreme reliability and interrelations.

• The Journal of Asian Finance, Economics and Business
• /
• 제7권10호
• /
• pp.391-399
• /
• 2020

This study aims to analyze the relationship of e-HRM implementation to employee performance both directly and indirectly through the intervening of the Human Resource service Quality variable, both practically and theoretically. This study uses variance-based structural equation modeling (SEM) techniques with partial least square (PLS) statistical testing tools to test the direct relationship of e-HRM and the performance and relationship moderated by Human Resources service quality tested on 200 civil servants in five offices under the coordination of the Government of the South Sulawesi Province of Indonesia. The data collection model in this study uses an online survey. The data analysis stages through the explanatory concept consist of, first, the interpretation of the distribution of the average frequency of respondents' answers; second, outer-loading; third, determination of the validity and reliability; fourth, the coefficient of determination test and partial test; fifth, the GoF model; sixth, validity test; and seventh, hypothesis testing. This study explores four hypotheses in a comprehensive fashion; the results of this study show that all hypotheses have positive and significant effects both through direct and intervening relationships. Among the three direct relationships, the relationship of e-HRM variables on HR Service Quality is greatest and most dominant.

• ETRI Journal
• /
• 제40권1호
• /
• pp.72-88
• /
• 2018

In the fifth generation (5G) era, the radio internet protocol capacity is expected to reach 20 Gb/s per sector, and ultralarge content traffic will travel across a faster wireless/wireline access network and packet core network. Moreover, the massive and mission-critical Internet of Things is the main differentiator of 5G services. These types of real-time and large-bandwidth-consuming services require a radio latency of less than 1 ms and an end-to-end latency of less than a few milliseconds. By distributing 5G core nodes closer to cell sites, the backhaul traffic volume and latency can be significantly reduced by having mobile devices download content immediately from a closer content server. In this paper, we propose a novel solution based on software-defined network and network function virtualization technologies in order to achieve agile management of 5G core network functionalities with a proof-of-concept implementation targeted for the PyeongChang Winter Olympics and describe the results of interoperability testing experiences between two core networks.