• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.34 no.1
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• pp.79-90
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• 2016

The study has purposed in evaluating experiences for achievable accuracy and precision of time series at 3-D coordinates. It has been estimated from the kinematic medium-range baseline processing of Continuously Operating Reference Stations (CORS) for the potential application of crustal displacement analysis during an earthquake event. To derive the absolute coordinates of local CORS, it is highly recommended to include some of oversea country references, since it should be compromised of an observation network of the medium-range baselines within the length range from tens of kilometers to about 1,000 kilometers. A data processing procedure has reflected the dynamics of target stations as the parameter estimation stages, which have been applied to a series of experimental analysis in this research at the end. From the analysis of results, we could be concluded in that the subcentimeters-level of positioning accuracy and precision can be achievable. Furthermore, the paper summarizes impacts of satellite ephemeris, data lengths and levels of initial coordinate constraint into the positioning performance.

• Journal of Positioning, Navigation, and Timing
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• v.12 no.4
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• pp.437-445
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• 2023

A space system refers to a network of sensors, ground systems, and space-craft operating in space. The security of space systems relies on information systems and networks that support the design, launch, and operation of space missions. Characteristics of space operations, including command and control (C2) between space-craft (including satellites) and ground communication, also depend on wireless frequency and communication channels. Attackers can potentially engage in malicious activities such as destruction, disruption, and degradation of systems, networks, communication channels, and space operations. These malicious cyber activities include sensor spoofing, system damage, denial of service attacks, jamming of unauthorized commands, and injection of malicious code. Such activities ultimately lead to a decrease in the lifespan and functionality of space systems, and may result in damage to space-craft and, lead to loss of control. The Cybersecurity Adversarial Tactics, Techniques, and Common Knowledge (ATT&CK) matrix, proposed by Massachusetts Institute of Technology Research and Engineering (MITRE), consists of the following stages: Reconnaissance, Resource Development, Initial Access, Execution, Persistence, Privilege Escalation, Defense Evasion, Credential Access, Discovery, Lateral Movement, Collection, Command & Control, Exfiltration, and Impact. This paper identifies cybersecurity activities in space systems and satellite navigation systems through the National Institute of Standards and Technology (NIST)'s standard documents, former U.S. President Trump's executive orders, and presents risk management activities. This paper also explores cybersecurity's tactics attack techniques within the context of space systems (space-craft) by referencing the Sparta ATT&CK Matrix. In this paper, security threats in space systems analyzed, focusing on the cybersecurity attack tactics, techniques, and countermeasures of space-craft presented by Space Attack Research and Tactic Analysis (SPARTA). Through this study, cybersecurity attack tactics, techniques, and countermeasures existing in space-craft are identified, and an understanding of the direction of application in the design and implementation of safe small satellites is provided.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.3 no.2
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• pp.31-44
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• 2008

A selection technique for innovative projects on the beginning stage has been presented in this article. It can be applied in projects assessment in HEI, enterprises, development institutes, etc. It is rather difficult to assess the project quality on the beginning stage of R&D due to the uncertainty in the technical and economic indices but the new development analysis on this stage is of a great interest. By innovative project quality as a management object we will mean those characteristics relating to the results capacity of the projects and its realization process to satisfy the requirements to the innovative products competitiveness and their innovative attractiveness for investors. The most important question in the innovative projects management is the determination of its quality level under modern conditions. The aim of the research is to analyze and evaluate the decision making during the project management process. The objectives and hypotheses are assessment of an innovative project with the application of McKinsey's model is better to realizes by 3 stages: a) selection of optimal criteria; b) determination of weighing coefficients; c) projects positioning in a matrix.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.939-944
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• 2007

Generally, development of a robot capable of fast movements or high payloads is progressed by the analysis of dynamic characteristics, DOF positioning, actuator selection, structure of links, and so on. This paper highlights the design of a robot manipulator handled by a human for man-machine cooperation. The requirements of the proposed system include its having multi-DOF(Degree of Freedom)and the capacity for a high payload in the condition of its maximum reach. The primary investigation factors are motion range, performance within the motion area, and reliabilityduring the handling of heavy materials. Traditionally, the mechanical design of robots has been viewed as a problem of packaging motors and electronics into a reasonable structure. This process usually transpires with heavy reliance of designerexperience. Not surprisingly, the traditional design process contains no formally defined rules for achieving desirable results, as there is little opportunity for quantitative feedback during the formative stages. This work primarily focuses on the selection of proper joint types and link lengths, considering a specific task type and motion requirements of the heavy material handling.

• Journal of the Korean Home Economics Association
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• v.39 no.4
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• pp.1-18
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• 2001

Korea huts been dramatically changed during the last century in many aspect of society, with the introduction of western culture in the beginning of 20th century. This study aims at understanding the changes in our traditional culture shown by costume as well as examining the aspects of the changes of traditional clothing according to age, by comparing the differences of our traditional dress Hanbok between ear1y and the late of the 20th century. Analysis of photographs showing Hanbok of both ages was used. 155 photographs of people wearing traditional Hanbok in the beginning of the 20th century were collected from the photo collection books portraying various living conditions of common people at that time. 748 Photographs of Hanbok worm today were obtained by taking pictures of various occasions like wedding ceremonies in 5 big cities during 1997. The process of analysis consists of 3 stages: setting standards, sorting, and grouping by positioning. The results showed that traditional Hanbok room in the early 20th century has maintained its basic silhouette and design during the century, but the methods of color coordination, ornamentation, construction have underdone many changes in detail. Consequently, traditional frame exits, but actually there are many variations of tradition produced by individual tastes and fashion trend. These changes show that continuing influx of the western culture which has made enormous social changes in Korea had an influence even on Hanbok.

• The Magazine of the IEIE
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• v.23 no.11
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• pp.89-100
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• 1996

A new stage-sliced pipiline structure is presented to design a high speed real time Global Positional Systems(GPS) applications. The CORDIC algorothm was revised to generate a pipeline structure, which will be used to produce a large amount of trigonometric computations rapidly. A stage-sliced approach was introduced to adjust the number of interative processes, and thereby to control the precision of computation results. Both the computation and the control circuits of the proposed architecture are included in a pipeline stage, which are intergrated into a stage slice. The circuit was prototyped using six FPGA chips : one is used for glue logics and five of the chips are used for pipeline slice implementation. A single FPGA chip comprising 7 pipeline stages provides one pipeline slice. To compensate and inter-slice time delay, dummy cycles are introduced in inter-slice signal exchanges.

• International Journal of Precision Engineering and Manufacturing
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• v.8 no.2
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• pp.64-69
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• 2007

Aerostatic planar XY stages are frequently used as the main frames of precision positioning systems. The machining and assembly process of the rails and bed of the stage is one of first processes performed when the system is built. When the system is complete, the 2D position, motion, and stage flatness errors are measured in tests. If the stage errors exceed the application requirements, the stage must be remachined and the assembly process must be repeated. This is difficult and time-consuming work. In this paper, a method for estimating the errors of a planar XY stage is proposed that can be applied when the rails and bed of the stage are evaluated. Profile measurements, estimates of the motion error, and 2D position estimation models were considered. A comparison of experimental results and our estimates indicated that the estimated errors were within $1{\mu}m$ of their true values. Thus, the proposed estimation method for 2D position and flatness errors of an aerostatic planar XY stage is expected to be a useful tool during the assembly process of guideways.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.21-26
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• 2006

This paper focuses on modeling and predicting differential GPS corrections transmitted by marine radio-beacon systems using artificial neural networks. Various neural network structures with various training algorithms were examined, including Linear, Radial Biases, and Feedforward. Matlab Neural Network toolbox is used for this purpose. Data sets used in building the model are the transmitted pseudorange corrections and broadcast navigation message. Model design is passed through several stages, namely data collection, preprocessing, model building, and finally model validation. It is found that feedforward neural network with automated regularization is the most suitable for our data. In training the neural network, different approaches are used to take advantage of the pseudorange corrections history while taking into account the required time for prediction and storage limitations. Three data structures are considered in training the neural network, namely all round, compound, and average. Of the various data structures examined, it is found that the average data structure is the most suitable. It is shown that the developed model is capable of predicting the differential correction with an accuracy level comparable to that of beacon-transmitted real-time DGPS correction.

• Archives of design research
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• v.18 no.3 s.61
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• pp.139-148
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• 2005

Generally, the brand has its life cycle as the product has. This life cycle is classified into the stages; introduction, growth, maturity and decline. Since the brand is little different from that of the product's, we can find some differences when it applies to the brand. The most effective method to perceive the brand to the consumers is advertisement, therefore in the advertisement design, it is important to figure out the current stage in the brand life cycle and use the most ideal design strategy in that stage. This study suggests the concept of the brand life cycle and the most effective strategy in each stages of the advertisement design. In the stage of the brand introduction, we apply the 'What is it? Strategy' which introduces the brand itself. In the stage of the growth, 'How does it Differ from? Strategy' is suggested as the advertisement strategy emphasizing the positioning which shows its differential competitive advantages among brands because in this stage there are many competitive brands in the market. In the stage of the maturity, we focus on the 'What does it Convey of? Strategy' stressing on the delivery of brand's value to consumers as consumers they purchase the brand. Finally in the stage of the decline, 'What does it Stand for? Strategy' is suggested in order to emphasize the generation of brand's symbolical meaning rather than to emphasize it's attributes or benefits. Therefore the advertisement design needs the contingent ideal design strategy according to the stages of brand life cycle and the effective brand management through it.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1883-1886
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• 2005

In this paper, a decoupled dual servo (DDS) stage for ultra-precision scanning system with large working range is introduced. In general, dual servo systems consist of a fine stage for short range and a coarse stage for long range. The proposed DDS also consists of a $XY\theta$ fine stage for handling and carrying workpieces and one axis coarse stage. Its coarse stage consists of air bearing guide system and a coreless linear motor with force ripple. The fine has four voice coil motors(VCM) as its actuator. According to a VCM's nature, there are no mechanical connections between coils and magnetic circuits. Moreover, VCM doesn't have force ripples due to imperfections of commutation components of linear motor systems - currents and flux densities. However, due to the VCM's mechanical constraints the working range of the fine is about $25mm^2$. To break that hurdle, the coarse stage with linear motors is used to move the fine about 500mm. Because of the above reasons, the proposed DDS can achieve higher precision scanning than other stages with only one servo. With MATLAB's Sequential Quadratic Programming (SQP), the VCMs are optimally designed for the highest force under conditions and constraints such as thermal dissipations due to its coil, its size, and so on. And for their movements without any frictions, guide systems of the DDS are composed of air bearings. To get precisely their positions, a linear scale with 5nm resolution are used for the coarse stage's motion and three plane mirror laser interferometers with 5nm for the fine's $XY\theta$ motions. With them, on scanning the two stages have same trajectories. The control algorithm is named Parallel method. The embodied ultra-precision scanning system has sub 100nm following error and in-positioning stability.