• Wind and Structures
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• 제4권1호
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• pp.63-72
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• 2001

This paper presents results of a study on wind loads and wind induced dynamic response of bridge jointed twin-towered buildings. Utilizing the high-frequency force balance technique, the drag and moment coefficients measured in wind tunnel tests, and the maximum acceleration rms values on the top floor of towers, are analyzed to examine the influence of building's plan shapes and of intervals between towers. The alongwind, acrosswind and torsional modal force spectra are investigated for generic bridge jointed twin-towered building models which cover twin squares, twin rhombuses, twin triangles, twin triangles with sharp corners cut off, twin rectangles and individual rectangle with the same outline aspect ratio as the twin rectangles. The analysis of the statistical correlation among three components of the aerodynamic force corroborated that the correlation between acrosswind and torsional forces is significant for bridge jointed twin-towered buildings.

• The Journal of Asian Finance, Economics and Business
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• 제8권5호
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• pp.617-626
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• 2021

The study examines the existence of twin deficit in two emerging economies (Turkey and Iran) and also investigates the relation of twin deficit with specific macroeconomic indicators such as the GDP, money supply, foreign direct investment, and the interest rate both in short and long-run periods. The twin-deficit concept refers to a situation where the current account deficit and budget deficits exist in the same corresponding period of an economy. This study employs the Bound Test Autoregressive lag distributed (ARDL) model on time-series quarterly secondary data of Turkey and Iran from 1992 to 2019. The stationarity of variables has been ensured through the Augmented Dickey-Fuller (ADF) test at the level and the first difference. The results reveal the existence of a twin deficit in both the short and long-run periods only in Iran. Its existence could not be observed in the Turkish economy. The findings suggest a positive relationship between twin deficit and GDP, and a negative relationship between twin deficit and FDI and M2. At the same time, the relationship of the twin deficit with interest rate could not be found in the Iranian economy. The findings may be helpful for economic managers of both countries in executing their economic policies.

• 대한조선학회논문집
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• 제41권1호
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• pp.15-22
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• 2004

Twin-skeg type stern shapes are recently adopted for very large commercial ships. However it is difficult to apply a CFD system to a hull form having twin-skeg, since grid topology around a twin-skeg type stern is more complicated than that of a conventional single-screw ship, or of an open-shaft type twin-screw ship with center-skeg. In the present study a surface mesh generator and a multi-block field grid generation program have been developed for twin-skeg type stern. Furthermore, multi-block flow solvers are utilized for potential and viscous flow analysis around a twin-skeg type stern The present computational system is applied to a 15,000TEU container ship with twin-skeg to prove the applicability. Wave profiles and wake distribution are calculated using the developed flow analysis tools and the results are compared with towing tank measurements.

• International Journal of Advanced Culture Technology
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• 제10권3호
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• pp.397-403
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• 2022

The world is paying a lot of attention to digital twins to preoccupy future technological competitiveness. Digital twins can be used in various fields such as manufacturing, medical care, and cities. Various market research institutes predict that the market size of digital twins will gradually expand. Korea has also selected digital twin as one of the representative tasks of the Korean version of the New Deal and is promoting related policies. However, a common platform or standard for building digital twins is not enough. Interoperability is a very important characteristic for the purpose of creating new value through interconnection between digital twins rather than independently developing and utilizing digital twins. The Digital Twin Consortium is an international council for the effective development and utilization of digital twins, and is working to solve the problem of digital twin interoperability. The Digital Twin Consortium recently published the 'Digital Twin System Interoperability Framework', and this paper analyzes the digital twin interoperability based on it.

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

• 한국연소학회:학술대회논문집
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• 한국연소학회 2004년도 제28회 KOSCO SYMPOSIUM 논문집
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• pp.49-56
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• 2004

A two-dimensional twin-jet counterflow system has been designed, in which two streams from two double-slit nozzles form a counterflow. This flow system enables one to systematically investigate various effects on non-premixed flames, including the non-premixed flame interaction, the edge flame behavior and the effect of curvature. Non-premixed flame interaction in the twin-jet counterflow system has been investigated numerically for methane fuel diluted with nitrogen. Three types of non-premixed flame(conventional counterflow flame, crossed twin-jet flame and petal shaped flame) were simulated depending on the combination of fuel/oxidizer supply to each nozzle. The extinction characteristics of non premixed methane flame in the twin-jet counterflow have been investigated numerically. The boundary of the existence of petal-shaped flames was identified for the twin-jet counterflow flames. Due to the existence of the unique petal-shaped flames, the extinction boundary for the twin-jet counterflow can be extended significantly compared to that for the conventional counterflow non-premixed flames, through the interaction of two flames. Through the comparison of the crossed twin-jet flame and the conventional counterflow flame, structure of the crossed twin-jet counterflow flame is analysed. Through the comparison of the petal shaped flame and the conventional counterflow flame, the extension of the extinction boundary for the twin-jet counterflow is investigated.

• 기술사
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• 제33권3호
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• pp.59-63
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• 2000

The purpose of this study is to understand the method of scheduling of Petronas twin tower project. Petronas twin tower is the highest building in the world today. Kuala Lumpur City Center Berhad which is owner of Petronas twin tower, managed this construction project by use of useful scheduling techniques, that is, milestone, NSC, NS, PDM, rolling wave, hammock. Now we consider this techniques and try to apply to our construction management.

• 정보처리학회 논문지
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• 제13권2호
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• pp.26-33
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• 2024

최근에 들어 디지털 트윈 기술에 대한 관심이 급증하고 있다. 디지털 트윈은 컴퓨터 기반 시뮬레이션을 통해 물리적 현상이나 사물을 모사함으로써 대상을 최적화하는 기술이다. 현재는 특정 분야에 국한되는 프로세스를 최적화하기 위한 단일 디지털 트윈이 개발되고 있지만, 독립된 디지털 트윈만으로는 현실의 방대하고 복합적인 프로세스를 분석하기 어렵다. 이를 극복하고자 도입된 개념이 연합 디지털 트윈이다. 지금까지 연합 디지털 트윈의 연구 방향은 주로 도시와 같이 거시적인 대상을 최적화하는 방식에 중점을 두었다. 그러나 트윈이 상호 연계된다는 특성을 활용하면 기존에 구현되었던 단일 디지털 트윈의 모듈화도 가능할 것으로 보인다. 본 연구에서는 프로세스 최적화와 관련된 기능상의 관점에서 단일 디지털 트윈과 연합 디지털 트윈의 개념 및 상호 관계를 정립하고, 이를 토대로 연합 디지털 트윈을 활용한 단일 디지털 트윈의 모듈화 기법을 설계한다. 아울러, 실제 면 제조 공정 사례를 바탕으로 모듈화 기법을 적용한 모델을 설계함으로써 제안하는 방법론의 효용성을 논의하고자 한다.

• 한국수정란이식학회지
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• 제11권3호
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• pp.301-307
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• 1996

This study was carried out to produce twin calves by embryo transfer in Hanwoo and investigate the pregnancy and twin rate by recipient's conditions. All recipients were bred at estrus by artificial insemination with Hanwoo semen and then transfered an additional embryo produced in vivo or in vitro to tbe uterine horn contralateral to the corpus luteum on Day 7. The results obtained were as follows ; 1. The pregnancy rate was higher in young recipients of 3 years (68.8%) than in old ones of 10 years and greater(36.4%). And for CL size pregnancy rate was 57.9, 45.4 and 60.1% in large, medium and small size of CL of recipients, respectively. 2. 447recipients were transferred an additional embryos at 7th day after Al and average pregnancy rate was 57.5% and twin production rate was 22.2%. 3. Average pregnancy and twin production rate by direct transfer methods of frozenthawed IVF embryos was 56.0 and 16.7%. 4. The ratio of male to female twin in a total of 55 twin pairs was 54.6%, and average gestation lengths of male to female and female to female twin were 280.6$\pm$5.4 and 279.715.4 days, respectively. Average birth weight of twins was beavior in male and male twin(23.2i5.8kg) than in male and female twin(20.5$\pm$2.6kg).

• Genomics & Informatics
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• 제3권4호
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• pp.159-165
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• 2005

The Korean Twin Register (n=154,783 pairs) was reported in 2002 as the first nationwide twin study in Korea and the largest study in Asia. The Twin Register has the information of disease outcomes since 1990, and basic clinical and questionnaire data from biennial health examination provided by Korea National Health Service. The author attempted to calculate some of the genetic parameters of cancers in this population. Common cancers in Korea known to have familial aggregation (colon and breast) and cancers of which familial aggregation is unclear (stomach cancer) were examined for their familial recurrence risks. There were 699 stomach cancers, 438 breast and 491 colorectal cancers cases in the twin register between 1991 and 2003. Like-sex twins showed recurrence risks (${\lambda}_{LS}$) of 5.1 (95% CI 3.7-6.9) for stomach cancers, 15.5 (95% CI1 0.9-20.2) for female breast cancers, and 28.1 (95% CI 23.5-34.4) for colon cancers. Colorectal cancers of female like-sex twins show significantly higher familial recurrence risk 40.7 (95% CI 34.6-47.4), suggesting higher genetic contribution in women than in men. The results show increased familial risks compared with previous studies from the same register and are largely compatible with other studies. The data of the Twin Register could be used for estimating population level genetic parameters, as well as base of the various studies.