• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.6
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• pp.635-642
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• 2014

In this paper, an efficient technique is developed to predict failure probability of three failure modes(case rupture, fracture and bolt breakage) related to solid rocket motor case due to the inner pressure during the mission flight. The overall procedure consists of the steps: 1) design parameters affecting the case failure are identified and their uncertainties are modelled by probability distribution, 2) combustion analysis in the interior of the case is carried out to obtain maximum expected operating pressure(MEOP), 3) stress and other structural performances are evaluated by finite element analysis(FEA), and 4) failure probabilities are calculated for the above mentioned failure modes. Axi-symmetric assumption for FEA is employed for simplification while contact between bolted joint is accounted for. Efficient procedure is developed to evaluate failure probability which consists of finding first an Most Probable Failure Point(MPP) using First-Order Reliability Method(FORM), next making a response surface model around the MPP using Latin Hypercube Sampling(LHS), and finally calculating failure probability by employing Importance Sampling.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.7
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• pp.827-833
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• 2019

There are several factors to consider for a ship to enter or depart a port safely. It is particularly important to identify the tides in the port to reduce the risk of stranding the ship. Most previous studies have focused on finding and analyzing harmonic constants. However, the research on the analysis and accuracy of harmonic constants in other hydrographic agencies is lacking. In this study, six Korean ports (Incheon, Gunsan, Yeosu, Busan, Ulsan, and Sokcho) were compared to the British and Korean tide tables based on actual information. To find the cause of tidal difference, the tide height, tide time, and form factor were calculated using harmonic constants. The information was then compared with British and Korean data. As a result of the difference in analysis of actual information and tide tables, there was a difference between the actual tide height and time at each port. The cause was found to be the difference in the harmonic constant, tide, and form factor between the UK and Korea. Therefore, this study, the Korean standard port should be added to the British tide table, and harmonic constants, which are the criteria for creating tides, must be constantly updated with the latest information. Additionally, the tide tables produced in each country are more accurate than the tide tables produced in UK.

• Science of Emotion and Sensibility
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• v.11 no.4
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• pp.531-540
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• 2008

This study, based on the college life style and the courage to make that the purpose of the design process of finding out the correlation. Chinese students study the life style can be categorized into 4 kinds. The courage to top a crowded bottom with a broad form of courage prefer to be brought down, getting smaller and smaller. Regular and relevant inclination stores are independent of trust. 2 as a whole are crowded with smooth curves and the courage to the asymmetric shape is preferred. Active investment, emphasis on foreign languages, tends to prefer shopping on the Internet were related.3 outstanding courage, just a little crowded in the cylindrical form is preferred. Trust the big stores, stores see the taste, his taste for products that are relevant to the tendency of pursuing said. 4, a lot of the colony gradient technique Protruding prefer to be in the form of courage. Home will, that tends to emphasize the brand and design were related. Home will, that tends to emphasize the brand and design were related. To recap the contents of the consumer lifestyle, based on the characteristics of their favorite cosmetics containers vary designs. Different forms, depending on their courage to feel emotions that can see the image. Therefore, the design in courage cosmetics on the characteristics of these granular for consumer research, the granular form of product research and the relationship between the elements in their care are made. The marketing strategy is in the consumer market, but needs more fine-grained analysis methods that can tell people.

• Journal of Communications and Networks
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• v.17 no.1
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• pp.58-66
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• 2015

Aeronautical communication networks (ACN) is an emerging concept in which aeronautical stations (AS) are considered as a part of multi-tier network for the future wireless communication system. An AS could be a commercial plane, helicopter, or any other low orbit station, i.e., Unmanned air vehicle, high altitude platform. The goal of ACN is to provide high throughput and cost effective communication network for aeronautical applications (i.e., Air traffic control (ATC), air traffic management (ATM) communications, and commercial in-flight Internet activities), and terrestrial networks by using aeronautical platforms as a backbone. In this paper, we investigate the issues about connectivity, throughput, and delay in ACN. First, topology of ACN is presented as a simple mobile ad hoc network and connectivity analysis is provided. Then, by using information obtained from connectivity analysis, we investigate two communication models, i.e., single-hop and two-hop, in which each source AS is communicating with its destination AS with or without the help of intermediate relay AS, respectively. In our throughput analysis, we use the method of finding the maximum number of concurrent successful transmissions to derive ACN throughput upper bounds for the two communication models. We conclude that the two-hop model achieves greater throughput scaling than the single-hop model for ACN and multi-hop models cannot achieve better throughput scaling than two-hop model. Furthermore, since delay issue is more salient in two-hop communication, we characterize the delay performance and derive the closed-form average end-to-end delay for the two-hop model. Finally, computer simulations are performed and it is shown that ACN is robust in terms of throughput and delay performances.

• Journal of the Korea Furniture Society
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• v.20 no.6
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• pp.543-551
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• 2009

The history repeatedly shows that designers have sought their creative inspiration from fine arts. was also influenced by contemporary art such as surrealism or installment works. This thesis aims to examine the inter-relationship between contemporary art and contemporary furniture design with examples of organic modernism and minimalism furniture design. Also, will be analyzed in light of such interdisciplinary relationship, explaining the significances of in scholastic perspective. The previous research analysis of finding out examples of how fine art and design sought mutual exchanges to develop will help to examine the significance of in the context of art history. This analysis could be used as an important academic material to understand the origin and characteristics of modern design furniture. The features of surrealism and minimalism will be discussed in light of their influences on and interactive relationship with organic modernism furniture design. This provides important basic material to further analyze . Furthermore, the artistic language and plastic features of contemporary sculptors and installment artists such as Jean Arp, Richard Serra and Anish Kapoor will be examined to show how integrated and combined main features of those artists. extracted cognitive and phenomenological aspects from Serra's works that overwhelm viewers with their massive scales. Somewhat abstract yet somewhat primitive and dynamic features of Arp's works was also referred to . are made of FRP, composed of three partitions and six stools. This work was analyzed in aspect of form, composition and function. They have organic and flexible formations with free composition availability which endow free disassemble and arrangement. Also, they have cognitive features as of small elements are freely dispersed upon spaces to bestow certain presences. Based on this, this thesis could develop scholastic researches that examine the mutual and interactive relationship between contemporary art and furniture design with much more detailed discussions and examples.

• Journal of Korean Association for Spatial Structures
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• v.12 no.3
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• pp.97-104
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• 2012

In the design procedure of the cooling tower the form-finding of the shell is the most important process, because the shape of the shell determines the sensitivity of dynamic behaviour of the whole tower against wind excitation. In engineering practice, geometric parameters of the shell are generally determined based on natural frequency analysis. 32 cooling tower shell geometries were selected through variation of the geometric parameters of an existing cooling tower shell. They were evaluated based on the first natural frequency. From the result three representative cooling towers are selected for the analysis of the structural behaviour by means of linear FE-method. As a result, a hyperbolic rotational shell with the small radius overall will yield the shell geometry with a higher first natural frequency and thus a wind-insensitive structure.

• Journal of Digital Contents Society
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• v.16 no.6
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• pp.909-916
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• 2015

This paper presents a method to display the 3D vector fields by analyzing phase space. This method is based on the connections between ordinary differential equations and the topology of vector fields. The phase space analysis should be geometric interpolation of an autonomous system of equation in the form of the phase space. Every solution of it system of equations corresponds not to a curve in a space, but the motion of a point along the curve. This analysis is the basis of this paper. This new method is required to decompose the hexahedral cell into five or six tetrahedral cells for 3D vector fields. The critical points can be easily found by solving a simple linear system for each tetrahedron. The tangent curves can be integrated by finding the intersection points of an integral curve traced out by the general solution of each tetrahedron and plane containing a face of the tetrahedron.

• Survey Research
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• v.8 no.2
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• pp.91-115
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• 2007

OES survey as the national official statistics aims to provide the basic data for the national labor market policy and research such as the basic statistics for human resource supply policy, the prediction of employment by occupations, the decision of occupation, the occupational training and the finding jobs et al., at the levels of industrial and occupational classifications(3-digit). In order to achieve this objective, we analyze the OES data in 2005 and 2006 and propose the new sampling design using the long form data in Korea (10% sample data of census 2005). In this paper, we provide the criterion of sample allocation and derive the formular for estimator and error of it including the weighting procedure. From the proposed sampling design, we would expect that it contributes to the supply policy of human resource and the research for labor market.

• Journal of Information Processing Systems
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• v.14 no.3
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• pp.680-693
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• 2018

Nowadays, third-party applications form an important part of the mobile environment, and social networking applications in particular can leave a variety of user footprints compared to other applications. Digital forensics of mobile third-party applications can provide important evidence to forensics investigators. However, most mobile operating systems are now updated on a frequent basis, and developers are constantly releasing new versions of them. For these reasons, forensic investigators experience difficulties in finding the locations and meanings of data during digital investigations. Therefore, this paper presents scenario-based methods of forensic analysis for a specific third-party social networking service application on a specific mobile device. When applied to certain third-party applications, digital forensics can provide forensic investigators with useful data for the investigation process. The main purpose of the forensic analysis proposed in the present paper is to determine whether the general use of third-party applications leaves data in the mobile internal storage of mobile devices and whether such data are meaningful for forensic purposes.

• Korean Institute of Interior Design Journal
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• v.14 no.4 s.51
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• pp.19-26
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• 2005

Digital technology continually makes a space evolves. The real-time behavior design communicates the data with the situation of circumference of the space(visitors moving, interior and exterior situations). The space form was changed because it interfaces in real time. The purpose of this study was finding out the characteristics of real-time behavior space design through the analysis of space formative languages, sensorium, S-R and material. This study will be the one of basic references for the digital space design. The boundary of this study set limits to the works of digital space designer who applies the real-time exchanging data to their design among the digital space design works from 1996 to 2004. But it excepted from the real-time behavior space in virtual realty. Therefore, the objects of this study were the works of onl and NOX(paraSITE, Trans-port 2001, Muscle, MotormeCCa, Handdrawspace, Saltwater Pavilion, Son-O-House, H2O Expo). The method was the contents analysis of space formative languages(Greg Lynn's ten space formative languages; bleb, blob, branch, flower, fold, lattice, teeth, shred, skins and strand), sensorium, S-R and material. The results of the study are as follows: 1) The organizational elements; Space formative languages(bleb, blob, fold, shred, skins, strand), stimulation(Human Participation, Human Moving, Weather Conditions), and response(Spatial Moving, Sound Pattern, Lighting Pattern, color Pattern, Activating Particles, Moving Picture, Virtual Friend) 2) The material Use; Sound, lights, and network have been used in the space. Immaterial matter will be used the main material of space design in 21"'century, 3)The spatial types; formal changing of space, projecting immaterial elements, and changing the sound.