• Bulletin of the Korean Mathematical Society
• /
• v.26 no.2
• /
• pp.169-173
• /
• 1989

Let V={(x,y,z):f=z$^{n}$ -npz+(n-1)q=0 for n .geq. 3} be a compled analytic subvariety of a polydisc in $C^{3}$ where p=p(x,y) and q=q(x,y) are holomorphic near (x,y)=(0,0) and f is an irreducible Weierstrass polynomial in z of multiplicity n. Suppose that V has an isolated singular point at the origin. Recall that the z-discriminant of f is D(f)=c(p$^{n}$ -q$^{n-1}$) for some number c. Suppose that D(f) is square-free. then we prove that by Theorem 2.1 .mu.(p$^{n}$ -q$^{n-1}$)=.mu.(f)-(n-1)+n(n-2)I(p,q)+1 where .mu.(f), .mu. p$^{n}$ -q$^{n-1}$are the corresponding Milnor numbers of f, p$^{n}$ -q$^{n-1}$, respectively and I(p,q) is the intersection number of p and q at the origin. By one of applications suppose that W$_{t}$ ={(x,y,z):g$_{t}$ =z$^{n}$ -np$_{t}$ $^{n-1}$z+(n-1)q$_{t}$ $^{n-1}$=0} is a smooth family of complex analytic varieties near t=0 each of which has an isolated singularity at the origin, satisfying that the z-discriminant of g$_{t}$ , that is, D(g$_{t}$ ) is square-free. If .mu.(g$_{t}$ ) are constant near t=0, then we prove that the family of plane curves, D(g$_{t}$ ) are equisingular and also D(f$_{t}$ ) are equisingular near t=0 where f$_{t}$ =z$^{n}$ -np$_{t}$ z+(n-1)q$_{t}$ =0.}$ =0.

• Journal of the Korean Society for Precision Engineering
• /
• v.26 no.7
• /
• pp.134-141
• /
• 2009

Recently, many researchers have tried to develop wearable robots for various fields such as medical and military purposes. We have been studying robotic exoskeletons to assist the motion of persons who have problems with their muscle function in daily activities and rehabilitation. The upper-limb motions (shoulder, elbow and wrist motion) are especially important for such persons to perform daily activities. Generally for shoulder motion 300F is needed to describe its motion(extension/flexion, abduction/adduction, internal/external rotation) but we have used a redundant actuator thus making a 4 DOF system. In this paper, we proposed the mechanism design of the exoskeleton which consists of 4-DOF for shoulder and 1-DOF for elbow robotic exoskeleton to assist upper-limb motion. Then we compared the new mechanism design and prototype mechanism design. Here we also analyze the proposed system kinematically to find out and to avoid the singular point. This research will ensure that the proposed wearable robot system make human's motion more powerfully and more easily.

• Korean Institute of Interior Design Journal
• /
• v.23 no.5
• /
• pp.67-75
• /
• 2014

Architecture is not only coming out of the making of a building room but also contributing to the making of an urban room. "The inside is not a contradiction of the outside...architecturally opened". (De Carli, 1967) The urban room is felt as a sense of rapport between building and city because architecture makes the building room closed simultaneously open toward the city. Architecture exists between both rooms. There is the possibility of integrating, by the conception of interior, architecture and urbanism and thus, the possibility of giving a theoretical ground to Interior Architecture/Design; "all architecture is interior architecture". (Ottolini, 1996) It is in line with the idea of the "Fusing: Landscape/Urbanism/Architecture". (Holl, 2009) The paper deals with, through literature review, a possibility of the fusing: Interior/Architecture/Landscape/Urbanism. The first site explores the meaning of the urban place as a thing, which gives a possibility of combining the building interior and the urban interior. The second site illustrates the idea of the urban interior for dwelling. The urban interior is definitely a place of dwelling to keep human inhabitancy, which takes place in a united interior of the building interior and the urban interior. The third site clarifies the idea of the urban interior. While the building interior gives human being with the private stage, the urban interior provides him with the public stage of city life. The two different interiors constitute an interior world for his trajectory of dwelling. The last site traces the conceptual development of the urban interior. The trace comes to a conclusion that architecture, landscape, and urbanism can be unified by the conception of interior and the urban interior is an object of "Interior Architecture/Design". This paper is theorized as a twofold singular of the building interior and the urban interior. Ultimately, it is relevant to the theoretical principle of fusing interior/architecture/landscape/urbanism, and aims at offering a departing point to consider the urban interior as an object of "Interior Architecture/Design" and for the future studies of the urban interior.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.37 no.1
• /
• pp.28-35
• /
• 2009

This paper derives the equation of coordinated attitude formulation taking into account the orbital dynamics of a target vehicle and the attitude of a tracking satellite in geostationary orbit. The coordinated attitude is always to communicate with the ground station during the target tracking. Because the tracking satellite could perform high angle maneuver, MRP parameters having no singular point are used. Also for the sequential tracking of several target vehicles, the equation automatically making a coordinated attitude is suggested. Coordinated attitude flying and sequential tracking are confirmed through simulations. In short, this paper shows that a satellite could track a target vehicle and communicate with ground station simultaneously using the derived equation of coordinated attitude even though without a accuracy sensor.

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.383-388
• /
• 2005

Depth recovery in robot vision is an essential problem to infer the three dimensional geometry of scenes from a sequence of the two dimensional images. In the past, many studies have been proposed for the depth estimation such as stereopsis, motion parallax and blurring phenomena. Among cues for depth estimation, depth from lens translation is based on shape from motion by using feature points. This approach is derived from the correspondence of feature points detected in images and performs the depth estimation that uses information on the motion of feature points. The approaches using motion vectors suffer from the occlusion or missing part problem, and the image blur is ignored in the feature point detection. This paper presents a novel approach to the defocus technique based depth from lens translation using sequential SVD factorization. Solving such the problems requires modeling of mutual relationship between the light and optics until reaching the image plane. For this mutuality, we first discuss the optical properties of a camera system, because the image blur varies according to camera parameter settings. The camera system accounts for the camera model integrating a thin lens based camera model to explain the light and optical properties and a perspective projection camera model to explain the depth from lens translation. Then, depth from lens translation is proposed to use the feature points detected in edges of the image blur. The feature points contain the depth information derived from an amount of blur of width. The shape and motion can be estimated from the motion of feature points. This method uses the sequential SVD factorization to represent the orthogonal matrices that are singular value decomposition. Some experiments have been performed with a sequence of real and synthetic images comparing the presented method with the depth from lens translation. Experimental results have demonstrated the validity and shown the applicability of the proposed method to the depth estimation.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.33 no.4 s.111
• /
• pp.97-107
• /
• 2005

This study was carried out to construct accurate and scientific system of assessment indicators in selection of National Trust conservation areas, which was new concept of domestic environment movement and offer the raw data of new analytic method by introducing the fuzzy theory and weight for overcoming the uncertainty of ranking decision. To transform the Likert's scale granted to assessment indicators into the type of triangular fuzzy number(a, b, c), there was conversion to each minimum(a), median(b), and maximum(c) in applying membership function, and in using the center of gravity and eigenvalue, there was to decide the ranking. The rankings of converted values applied a mean importance and weight were confirmed that they were generally changed. Therefore, the ranking decision was better to accomplish objective and rational ranking decision by applying weight that was calculated in grouping of indicator than to judge the singular concept and to be useful in assessment of diverse National Trust site. In the future, because AHP, which was general method of calculating weight, was lacked, there was to understand the critical point to fix a pertinent weight, and to carry out the study applying engineering concept like fuzzy integral using $\lambda-measure$.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.41 no.5
• /
• pp.391-399
• /
• 2017

This paper presents the effects of the cutting speed and feed rate on the axial shape of flat end-milled down cut side walls. Experiments were performed using the cutting speed, tool diameter, and feed per tooth as variables, and the thrust force and axial shape were measured as the experimental results. The results of this study confirmed that a smaller feed per tooth, which is proportional to the value obtained by dividing the feed rate by the cutting speed, results in a higher axial shape accuracy. In addition, the axial shape can be simplified to a form in which two straight lines having different slopes meet at a singular point. Therefore, it was concluded that the shape accuracy could easily be estimated during the operation and improved by adjusting the feed per tooth.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.49 no.11
• /
• pp.159-166
• /
• 2012

There are several ways such as GPS(Global Positioning System) and INS (Inertial Navigation System) to track the location of moving vehicle. The GPS has the advantages of having non-accumulative error even if it brings about errors. In order to obtain the position information, we need to receive at least 3 satellites information. But, the weak point is that GPS is not useful when the 혠 signal is weak or it is in the incommunicable region such as tunnel. In the case of INS, the information of the position and posture of mobile with several Hz~several hundreds Hz data speed is recorded for velocity, direction. INS shows a very precise navigational performance for a short period, but it has the disadvantage of increasing velocity components because of the accumulated error during integration over time. In this paper, sensor fusion algorithm is applied to both of INS and GPS for the position information to overcome the drawbacks. The proposed system gets an accurate position information from experiment using SVD in a non-accessible GPS terrain.

• Journal of the Korean Society of Costume
• /
• v.66 no.1
• /
• pp.135-154
• /
• 2016

The purpose of this study is to research the characteristics and types applied to Korean and foreign luggage brands, and then develop pattern designs for the luggage by applying Korean cultural contents that meet the various fashion needs of travel goods. To select the Korean and foreign luggage brands, a web search was utilized by inputting the keyword, 'luggage brand'. The results, which were extracted from 200 web documents, produced 27 Korean brands and 29 foreign brands that met the requirements. For the data analysis, images and contents were collected through luggage brand websites, and then 927 pattern designs were extracted. The results were as follows. First, characters, figures, animals, and plants were commonly used for the pattern design motifs applied to Korean and foreign luggage. A notable trend was that these motifs were expressed in a stylistic way with a graphic touch. Also, a singular point was formed from the luggage overall, and regularly repeated patterns were very common as well. Secondly, pattern designs for luggage were developed through the application of 'Hangul', 'Hanbok', and 'Hanok'. Nine kinds of patterns were designed via the phases of change into a vector image and color adjustments, and were simulated in luggage design. Adobe Photoshop CS 7.0, and Adobe Illustrator CS 5.0 programs were used for the pattern designs and simulations. This study is meaningful in that it suggested pattern designs for different kinds of luggage in the motifs of Korean cultural contents. It can be used as a useful reference, as we are in a time period where travel goods have become individualized, advanced, and fashionable, as well as laying stress on original design based on cultural interpretation.

• Journal of the Korean Data and Information Science Society
• /
• v.26 no.6
• /
• pp.1259-1269
• /
• 2015

Recently, big data is positioning as a keyword in the academic circles. And usefulness of big data is carried into government, a local public body and enterprise as well as academic circles. Also they are endeavoring to obtain useful information in big data. This research mainly deals with analyses of box office success or failure of films using text mining. For data, it used a portal site 'D' and film review data, grade point average and the number of screens gained from the Korean Film Commission. The purpose of this paper is to propose a model to predict whether a film is success or not using these data. As a result of analysis, the correct classification rate by the prediction model method proposed in this paper is obtained 95.74%.