• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.3
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• pp.349-355
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• 2013

Recently, there is an increasing need to produce more precise products with small deviations from defined target values. Machine capability is the ability of a machine tool to produce parts within a tolerance interval. Capability indices are a statistical way of describing how well a product is machined compared to defined target values and tolerances. Today, there is no standardized way to acquire a machine capability value. This paper describes a method for evaluating machine capability indices in machining centers. After the machining of specimens, the straightness, roundness, and positioning accuracy were measured by using CMM (coordinate measuring machine). These measured values and defined tolerances were used to evaluate the machine capability indices. It will be useful for the industry to have standardized ways to choose and calculate machine capability indices.

• Journal of Positioning, Navigation, and Timing
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• v.12 no.4
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• pp.343-348
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• 2023

The ionosphere acts as the largest error source in the Global Navigation Satellite System (GNSS) signal transmission. Ionospheric total electron content (TEC) is also easily affected by changes in the space environment, such as solar activity and geomagnetic storms. In this study, we analyze changes in the regional ionosphere using the Qusai-Zenith Satellite System (QZSS), a regional satellite navigation system. Observations from 9 GNSS stations in South Korea are used for estimating the QZSS TEC. In addition, the performance of QZSS TEC is analyzed with observations from day of year (DOY) 199 to 206, 2023. To verify the performance of our results, we compare the estimated QZSS TEC and CODE Global Ionosphere Map (GIM) at the same location. Our results are in good agreement with the GIM product provided by the CODE over this period, with an averaged difference of approximately 0.1 TECU and a root mean square (RMS) value of 2.89 TECU.

• Journal of the Korean Society of Clothing and Textiles
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• v.16 no.2
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• pp.263-275
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• 1992

This study intends to provide strategic positioning of brand image analysed from the view point of perceptual dimensions of clothing consumers. Consumers are segmented on the basis of the attributes of brand image, and in each segment, perceptual map is composed according to multidimensional scaling. The results are as follows; 1. According to the Benefit Segmentation, it is statistically significant that the consumers are divided into 'product-factor oriented group 'and' image-factor oriented group'. 2. From the analysis of perceptual map upon the 'similarity of brand image,'image-factor oriented group 'perceives more differently than 'product-factor oriented group' 3. From the analysis of perceptual map with the evaluation of attributes of brand image, price, promotion and design are significant determinants in 'total consumer group'. In addition, store image is significant determinant in' image-factor oriented group' and quality is significant determinant in' product-factor oriented group'. According to the evaluation of consumers on 8 brands with determining attribute-vector, ranks of brands in each segment are similar in the vector of price and promotion but different in the vector of design between segment groups. 4. From the analysis of perceptual map upon the preference of brand image, the distribution of preference and position of ideal point are different between segment groups. 5. With evaluation of purchase habit, statistically significant differences are found between groups segmented in the degree of importance of attributes, purchasing motive, purchasing time, sources of information and expenses for clothes.

• Journal of Korean Society for Geospatial Information Science
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• v.10 no.1 s.19
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• pp.83-90
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• 2002

Control point survey by GPS can save labor and time and can obtain result of high accuracy, but if excessive error is contained to Control point that is used to GPS relative positioning, the error that has influence on new point is propagated to various configuration. therefore poor triangulation points that are caused by careless management are existed, a product of the triangulation points still are in many case. In order to select new point, this study carried out error-analysis of surrounding-control-points and performed selective process of control point. The propriety parts of control points that are used to verify precision is identified by means of comparing existing product with or GPS product about some control points after directly observe each baseline by using EDM. As the error is analyzed by static positioning the optimum control point is selected, the precision of survey data by EDM is improved than GPS data.

• Journal of Astronomy and Space Sciences
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• v.18 no.2
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• pp.129-136
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• 2001

The accuracy of GPS applications is heavily dependent on the satellite ephemeris and earth orientation parameter. Specially applications like as the real time monitoring of troposphere and ionosphere require real time or predicted ephemeris arid earth orientation parameter with very high quality. IGS is producing IGS ultra rapid product called IGU for real time applications which includes the information of ephemeris and earth orientation. IGU is being made available twice everyday at 3:00 and 15:00 UTC arid covers 48 hours. The first 24 hours of it are based on actual GPS observations and the second 24 hours extrapolated. We will construct the processing strategy for yielding ultra rapid product and demonstrate the propriety through producing it using 48 hours data of 32 stations.

• Journal of Digital Convergence
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• v.12 no.11
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• pp.273-279
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• 2014

In this paper, we propose a novel algorithm for three dimensional positioning system and implement a system over indoor wireless channel. A commercial modules are used for mobile and fixed nodes which are product of German company Nanotron Co. This module adopts chirp spread spreading scheme as modulation method to improve the ranging resolution and the module satisfies the IEEE standard 802.15.4a. The distance computation is based on received signal strength(RSS) levels and trilateration method. A testbed was set up to measure and compare the positioning estimation error of the proposed algorithm. The experiments results showed that the accuracy of location estimation was sufficiently good as much as 1m distance error in a wireless environment in an office building.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.11
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• pp.1551-1558
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• 2021

Beacon signals used in indoor positioning system are reflected and distorted, resulting in noise signals. KF(Kalman Filter) has been widely used to remove this noise. In order to apply the KF, optimization process considering the signal type, signal strength, and environmental elements of each product is required. In this paper, we propose a solution to the optimization problem of KF Parameters using GA(Genetic Algorithm) in BLE(Bluetooth Low Energy) Beacon-based indoor positioning system. After optimizing KF Parameters by applying the proposed technique with a certain distance between Beacon and receiver, we compared the estimated distance passed through KF with the unfiltered distance. The proposed technique is expected to reduce the time required and improve accuracy of KF Parameters optimization in an indoor positioning system based on RSSI (Received Signal Strength Indication).

• Fashion, Industry and Education
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• v.16 no.2
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• pp.30-39
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• 2018

This study investigates the importance of brand and retailer associations when consumers evaluate a product category extension in the context of brand and retailer collaborations. Although brand extensions are considered to reduce costs for introducing a new product category, limited study has focused on the role of brand and retailer associations in the context of brand and retailer collaborations. Using a total of 440 participants, a hypothesized model was tested using a structural equation modeling (SEM). The results show that brand and retailer associations influence the perceived fit between a brand and a retailer. In addition, the image fit and quality fit are significantly related to brand and retailer attitudes as well as brand extension evaluation. Since consumers may use their associations with brands or retailers when they perceive product differentiation, market position, and brand extensions, the role of brand or retailer associations is important to marketers, retailers, and consumers. Given the importance of brand and retailer collaborations as a brand positioning strategy in the global branding and retail setting, the findings of this study contribute to brand and retail management by providing empirical evidence on how consumers perceive new products from extended brands in the marketplace when a brand collaborates with a retailer.

• Product Safety
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• no.6 s.150
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• pp.62-65
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• 2006

위성항법장치 즉, GPS는 Global Positioning System의 약자로서, 비행기 · 선박 · 자동차뿐만 아니라 세계 어느 곳에서든지 인공위성을 이용하여 자신의 위치를 정확히 알 수 있는 시스템이다. 우리에게는 현재 지피에스(GPS)라고 더 잘 알려져 있다. GPS는 원래 미국에서 군사적 목적으로 1978년부터 개발이 시작되었다. 당초에는 요격미사일의 유도 등을 위하여 주로 사용되었으나, 냉전시대가 끝나면서부터 민간 영역으로 그 이용 범위가 점차 확대되어 현재는 항공기, 선박, 차량의 자동항법시스템 등에서 매우 유용하게 사용되고 있다. 그렇다면 지금부터 그 구성과 원리 등에 대해서 자세히 알아보도록 하자.

• Proceedings of the Technology Innovation Conference
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• 2000.06a
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• pp.105-120
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• 2000

Rapid spread of Internet, there appear so many commercial wedsites. Websites are not only tools to advertise a company or a product, but also value-added products inself. So we need a systematic approach(planning, design, implementation) to develop a website. But existing reserches on website development have corvered only technological issues such as network and HCI(Human Computer Intercation). In this research a framework is proposed to develop a website systematically using database of existing websites. This framework is composed of several stages-target customer segmentation, determination of services on website, dtermination of business model, functinal positioning, and evaution.