• Transactions of the Korean Society of Machine Tool Engineers
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• v.12 no.2
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• pp.71-78
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• 2003

This research proposes an implementation method of linearized equations of motion for multibody systems with closed loops. The null space of the constraint Jacobian is first pre-multiplied to the equations of motion to eliminate the Lagrange multiplier and the equations of motion are reduced down to a minimum set of ordinary differential equations. The resulting differential equations are functions of all relative coordinates, velocities, and accelerations. Since the variables are tightly coupled by the position, velocity, and acceleration level coordinates, direct substitution of the relationships among these variables yields very complicated equations to be implemented. As a consequence, the reduced equations of motion are perturbed with respect to the variations of all variables, which are coupled by the constraints. The position velocity and acceleration level constraints are also perturbed to obtain the relationships between the variations of all relative coordinates, velocities, and accelerations and variations of the independent ones. The Perturbed constraint equations are then simultaneously solved for variations of all variables only in terms of the variations of the independent variables. Finally, the relationships between the variations of all variables and these of the independent ones are substituted into the variational equations of motion to obtain the linearized equations of motion only in terms of the independent variables variations.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.05a
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• pp.331-334
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• 2009

An air-independent propulsion (AIP) system based on fuel cell technologies was developed for space and underwater applications in the present study. Hydrogen peroxide was selected as an oxidizer for space and underwater power applications where air independence is a must. Catalytic decomposition of hydrogen peroxide was used to generate oxygen and water. The pure oxygen was provided to a fuel cell and the water was stored separately. Sodium borohydride in the solid state was used as a hydrogen source in the present study. Pure hydrogen can be generated by a catalytic hydrolysis reaction. A fuel cell system was fabricated to validate the fuel cell based air-independent power system and was evaluated at the various conditions.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.8
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• pp.1303-1308
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• 2003

This research proposes an implementation method of linearized equations of motion for multibody systems with closed loops. The null space of the constraint Jacobian is first pre-multiplied to the equations of motion to eliminate the Lagrange multiplier and the equations of motion are reduced down to a minimum set of ordinary differential equations. The resulting differential equations are functions of ail relative coordinates, velocities, and accelerations. Since the coordinates, velocities, and accelerations are tightly coupled by the position, velocity, and acceleration level constraints, direct substitution of the relationships among these variables yields very complicated equations to be implemented. As a consequence, the reduced equations of motion are perturbed with respect to the variations of all coordinates, velocities, and accelerations, which are coupled by the constraints. The position, velocity and acceleration level constraints are also perturbed to obtain the relationships between the variations of all relative coordinates, velocities, and accelerations and variations of the independent ones. The perturbed constraint equations are then simultaneously solved for variations of all coordinates, velocities, and accelerations only in terms of the variations of the independent coordinates, velocities, and accelerations. Finally, the relationships between the variations of all coordinates, velocities, accelerations and these of the independent ones are substituted into the variational equations of motion to obtain the linearized equations of motion only in terms of the independent coordinate, velocity, and acceleration variations.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.893-898
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• 2004

This research proposes an implementation method of linearized equations of motion for multibody systems with closed loops. The null space of the constraint Jacobian is first pre multiplied to the equations of motion to eliminate the Lagrange multiplier and the equations of motion are reduced down to a minimum set of ordinary differential equations. The resulting differential equations are functions of all relative coordinates, velocities, and accelerations. Since the coordinates, velocities, and accelerations are tightly coupled by the position, velocity, and acceleration level constraints, direct substitution of the relationships among these variables yields very complicated equations to be implemented. As a consequence, the reduced equations of motion are perturbed with respect to the variations of all coordinates, velocities, and accelerations, which are coupled by the constraints. The position, velocity and acceleration level constraints are also perturbed to obtain the relationships between the variations of all relative coordinates, velocities, and accelerations and variations of the independent ones. The perturbed constraint equations are then simultaneously solved for variations of all coordinates, velocities, and accelerations only in terms of the variations of the independent coordinates, velocities, and accelerations. Finally, the relationships between the variations of all coordinates, velocities, accelerations and these of the independent ones are substituted into the variational equations of motion to obtain the linearized equations of motion only in terms of the independent coordinate, velocity, and acceleration variations.

• Journal of Distribution Science
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• v.11 no.9
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• pp.51-57
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• 2013

Purpose - This study investigates the effect of visual merchandising display (VMD) of local specialty retailer of private label apparel (SPA) brands, such as space, display, and presentation on brand awareness, brand image, and purchase intention. It investigates consumers' VMD awareness and purchase intention of SPA brands to help business activities of local SPA enterprises. Research designs, data, methodology - This study uses SPSS 18.0 to study eight local SPA brands and has 193 effective usable copies from a sample of 200. Results - The display and presentation of VMDs of SPA brands had a positive influence on brand awareness and brand image, which in turn had a positive influence on purchase intention. Conclusions - As SPA brands are increasingly located in supercenters, they face space constraints and find it difficult to display their facade and signs effectively. Therefore, decisions pertaining to display, presentation, and space should consider whether these SPA brands are launched as independent specialty shops or in supercenters. The space for VMD is considered important in independent shops. However, shops that open in supercenters should pay more attention to presentation rather than space.

• The Korean Journal of Air & Space Law and Policy
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• v.9
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• pp.435-443
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• 1997

Passing 26 years from 1970 when the first satellite was launched into the orbit, Japan developed and successfully launched H-II from Tanegashima Space Center in 1994. During those period, Japanese space policy has experienced a big shake from independent development to technology import from the US, and back again to independent development. In general, the H-II rocket which was manufactured by 100% domestic technology, brings Japan from the old era (experimental stage) to the new era (practical use stage). Fundamental Policy of Japan's Space Activities, which decides such policy as mentioned, was revised in January, 1996 this year after an interval of 7 years. This revised outline confirms the result of Japanese space technology until present and identifies the future direction and framework of her space activities for a period of coming ten years on the basis of a ong-term perspective towards the 21st century. However, when comparing with the last Fundamental Policy in 1989, there seems no big change in it, and a long-term perspective is also not seen there. The description varies on some important points in international space law, like international cooperation, protection of environment, commercial use, etc. In addition, the immaturity as well as the necessity of broader discussion are felt because neither this Fundamental Policy nor The National Defense Program Outline treated any national and international security matters concerning outer space. Considering the present time when Japan enters into the practical use of outer space, such as application, commercial use and launching service, etc, it is doubtful whether new Fundamental Policy was properly planned or not. It seems necessary to use several measures by which the public opinion, opinions from industry and debate on the security are reflected in the policy making.

• Phonetics and Speech Sciences
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• v.2 no.4
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• pp.185-192
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• 2010

The acoustic vowel space has been used as an acoustic parameter in dysarthric speech. The aim of this work was to examine mathematical formulae for acoustic vowel space and to apply these to Korean speakers with idiopathic Parkinson's disease(IPD). Five acoustic parameters were chosen from earlier works and one new parameter was proposed, the pentagonal vowel space. The six parameters included triangular vowel space (3 area), irregular quadrilateral vowel space (4 area), irregular pentagonal vowel space (5 area), vowel articulatory index (VAI), formant centralization ratio (FCR) and F2i/F1u ratio (F2 ratio). An experimental group of 32 IPD patients(male:female=16:16) and a control group of twenty healthy people (male:female=8:12) participated in the study and repeated vowels (/a-i-u-e-o/) three times. A correlation analysis was performed among the six parameters, 2-way ANOVA was done with gender and groups as independent factors, and an independent sample t-test was conducted between the male and the female group as post hoc comparison. All parameters were highly correlated with each other and only the FCR showed a high negative correlation with the others. The results of ANOVA showed a significant difference in F2 ratio, 3 area, 4 area and 5 area between gender and in 4 area and 5 area between groups. For the male members of the two groups, significant statistical differences were found in all parameters whereas no such differences were found for the female members. These findings indicated that the vowel space of the female group was wider than the vowel space of the male group. These differences may have been caused by gender-specific speech styles rather than by patho-physiological mechanisms. We also claim that the pentagonal vowel space is better than the other vowel spaces at representing the disordered speech in natural speech situations.

• Genomics & Informatics
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• v.18 no.1
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• pp.2.1-2.11
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• 2020

In this paper, we propose a new approach to detecting outliers in a set of segmented genomes of the flu virus, a data set with a heterogeneous set of sequences. The approach has the following computational phases: feature extraction, which is a mapping into feature space, alignment-free distance measure to measure the distance between any two segmented genomes, and a mapping into distance space to analyze a quantum of distance values. The approach is implemented using supervised and unsupervised learning modes. The experiments show robustness in detecting outliers of the segmented genome of the flu virus.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.401-406
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• 1991

An integrated control design and modeling method of multibody space structures is presented as a tool to control an d describe the large rotational motions of the space structures. The structures representeed with three separated substructures have independent control systems but linked with joints interacting the dynamic motions of the substructures. The effect of the structural flexibility to the control performance was analyzed and the simulation results showed that effectiveness of the designed control logic in controlling the motions of the multi-body space structures.

• Journal of the Korean housing association
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• v.6 no.1
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• pp.89-101
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• 1995

This study is to analyze dwelling environmental planning in old age of middle age. For this purpose. the data were collected by using questionnaire distributed to 332. The data were analyzed by Chisquare test. The major findings of this research were as follow: 1. In housing plan of old age. they prefer new house .that is not exisiting house. independent house and ordindry housing region in the suburbs of urban. 2. It is 69.3～99 square meter what size of house is suitable for independent life of aged person for living with children. it is 102.3～132 square meter. 3. In the stage of independent or semi-independent life. they want aged couple-independent life. In the stage of dependent life. they want to be cared with children. 4. The garden(madang) is the most important space for age couple in establishing housing plan. They want to amplity life recuperation center and job providing facilities. In old age housing project. they prefer housing type with facility that combine old age house with young age house. According to increasement of dependence. the service support system required flexi-care-system.