• IEIE Transactions on Smart Processing and Computing
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• v.3 no.3
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• pp.135-141
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• 2014

The inherent feature of the highly efficient spectrum usage has made Orthogonal Frequency Division Multiplexing (OFDM) preferable for Communication Standards. This study evaluated the performance of a Least Square (LS) estimator for a comb-type pilot insertion scheme over a fast fading Rayleigh channel. A High Peak-to-Average Power Ratio (PAPR) is one of the major downsides of the OFDM. The effects of an increase in the number of subcarriers on PAPR and the performance of the LS Estimator were studied. Increasing the number of subcarriers while keeping the pilots overhead constant resulted in improved performance of the LS estimator but the PAPR increased with increasing number of subcarriers. Therefore some trade-off between the number of subcarriers and the performance of the OFDM system is needed. The Mean Square Error (MSE) expression was also derived for the LS estimator in the case of a comb-type pilot arrangement. The MSE expression clearly explains the effects of the number of subcarriers on the performance of the LS estimator.

• International Journal of Reliability and Applications
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• v.18 no.2
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• pp.21-44
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• 2017

Accelerated life tests (ALTs) are frequently used in manufacturing industries to evaluate the reliability of products within a reasonable amount of time and cost. Test units are subjected to elevated stresses which yield quick failures. Most of the previous works on designing ALT plans are focused on tests that involve a single stress. Many times more than one stress factor influence the product's functioning. This paper deals with the design of optimum modified ramp-stress ALT plan for Burr type XII distribution with Type-I censoring under two stress factors, viz., voltage and switching rate each at two levels- low and high. It is assumed that usage time to failure is power law function of switching rate, and voltage increases linearly with time according to modified ramp-stress scheme. The cumulative exposure model is used to incorporate the effect of changing stresses. The optimum plan is devised using D-optimality criterion wherein the ${\log}_{10}$ of the determinant of Fisher information matrix is maximized. The method developed has been explained using a numerical example and sensitivity carried out.

• The Journal of Korean Association of Computer Education
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• v.6 no.3
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• pp.207-216
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• 2003

An instructor in education generally takes the objective-type evaluation for grading. The subjective-type evaluation has the merit that it can estimate the high-recognition ability, but the problem of the objectivity and reliability of the evaluation. This paper proposes the model which grades for the subjective-type evaluation. and designs and implements the evaluation system using the synonym thesaurus. This system can process the diverse and wide subjective-type questions and provide the easy usage for a beginner. It also can reduce the time and endeavor for evaluation and provide the objectivity of the evaluation. The system results the 73% success rate. We expect that this system will become a basis of the research on the subjective-type evaluation.

• Korean Institute of Interior Design Journal
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• v.18 no.6
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• pp.3-11
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• 2009

The ratio of old persons among the total population is rapidly increasing and the apartment has become to the representative housing type in Korea. This means that many old persons would live in multi-family houses. Therefore the study was intended to examine the preferred characteristics of interior space organization in multi-family house by the aged. The characteristics were the number and usage of bedroom, necessity and type of dress room, type of living room, arrangement of work centers in kitchen, LDK type, the number and layout of bathroom, and type of entrance and balcony. The subjects were 122 old persons who lived in multi-family houses in Ulsan. The individual interview was carried out for collecting the data. The results were as the followings; The characteristics of interior space organization in multi-family houses preferred by the elderly were three bedroom, two bathroom, DK or LDK type, open planned living room, L shape arrangement of kitchen work center, entrance connected directly to outdoor space such as elevator hall or corridor, and the balcony located in front of living room and at the back of small bedroom. Even thouth the average age of population has increased, many apartments still be planned and provided without consideration of old persons. This study would contribute to plan the multi-family houses for the elderly.

• The Journal of the Korea Contents Association
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• v.22 no.2
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• pp.487-500
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• 2022

This study aims to examine visitors' usage intention of the mobile AR(Augmented reality) application for tourism in Korea. For this purpose, the study analyzed how three attributes of AR tourguide app such as interactivity, vividness, and novelty have influenced on the tourist in terms of three realms of their flow, their experience (education, entertainment, esthetics, and escapism), and their usage intention for the future. It conducted an online survey from 20 to 30 year-old 291 participants and used a structural equation modeling. Survey findings show that first, novelty has a positive influence on the state of flow in AR application after vividness; Interactivity does not any significant effect on the tourists' flow. Second, when tourists explore the flow in the AR tourguide app, it affects all realms of experience economy of education, entertainment, esthetics, and escapism. Third, when using AR tour guide app in the context of historical heritage site, the two dimensions of entertainment and education influence the usage intention but the other two of esthetics and escapism does not. This study has presented a theoretical contribution that it focuses on historical sites as one type of tourist attractions and suggests a new modeling integrating AR attributes, flow, experience, and usage intention. In addition, it can be used to become a practical reference for revising an user-oriented AR application and customer-tailored AR tourism.

• Journal of the Korean Association of Geographic Information Studies
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• v.19 no.1
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• pp.120-140
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• 2016

The purpose of this study is to assess the green space considering functional characteristics in order to provide the base data for efficient green planning and management. The study area was the park-type green spaces in Daegu and the functions were limited in nature-ecological, environment-control, and usage functions. Thirteen indicators were selected from the literature review and MCB analysis of expert survey. The weightings of functional indicators were established through AHP analysis of expert survey. According to the results of functional assessment, Naengcheon amusement, Deagu sports, and Dalchang amusement parks had scores of more than 80 in the case of nature-ecological function. Fifteen parks such as Bokhyeon, Manchon, and Cheonnae parks had scores of more than 75 in terms of environment-control function and eleven parks such as Suseong, Dalseong, and Wolbae parks had scores of more than 80 in usage function. The findings from this study can be used as the base data and guideline for construction of new park-type green space and continuous management and remodeling of current green space.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2011.04a
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• pp.111-115
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• 2011

The purpose of this study was the analysis of electric energy consumption with the case study of tower type apartment's opening of building surface. We analyze the relationship between tower type apartment's opening of building surface and using electric energy consumption. The results of this study are: 1) The highest energy consumption of electric energy was on August without any influence of opening types of building surface. 2) Also, the south-west sides consumption of August was 848 kWh on Type B(one side opening) and it was the highest usage. 3) A house if facing west used more electricity than facing east when its opening of building surface's datum level is facing south. However, the house of facing east used more power than west when its opening of building surface's datum level is facing north. 4) When opening of building surface is facing on north-west or north-east, the opening of building surface's side of west and east used more electric power than north-west or north-east sides.

• Journal of the Korean housing association
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• v.5 no.2
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• pp.29-40
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• 1994

The purpose of this study is to survey the transition of the type of openings in korean traditional archiectures. To do this, various types of openings at the backside of Daechung of 23 Hyang-Gyo Myung-Ryun-Dangs were investigated. After the classification in some groups according to their types and their periods of constuction, the tasnsition of the type of openings was analysed. Results are as follows. (1) The openings constructed form 16th to 17th century, the earliest form, is a ledged and battened panel window(or framed and ledged panel window) whose mullion is built on the frame of window. It is presumed that these types were widely used before 17th century. (2) The next type is ledged and battened panel window(door) (or framed and ledged panel window) which lacks a mullion. These types were thought to be customed after 18th century. (3) The lastest type, which is appeared from 19th to 20th century, is an characteristic backside opening(ledged and battened panel window or framed and ledged panel window) that among 3 column spacings the central one is enlarged in comparison with the right and left ones. Through this transition pattern of the openings, can be menifested that the trend of 20th century is to enlarge convenience of usage by constuctiong door and eliminating some windows.

• Journal of the Korean Society of Food Culture
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• v.30 no.5
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• pp.481-490
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• 2015

This research was conducted to examine the awareness and preference levels related to MSG (monosodium glutamate) according to well-being dietary life pursuit attitude factors as well as to improve opportunities to meet value conscious consumption of well-being-oriented customers. According to well-being dietary life pursuit attitude factors, respondents were divided to three clusters, indifference type, well-being-oriented type, and active health action type. Sensory evaluations were carried out on soybean paste soup (Doenjang-guk) and seasoned spinach with different levels of MSG. In the results, 74.4% of all respondents preferred Doenjang soup with 2% MSG, 65.4% preferred seasoned spinach with the same ratio of MSG, and 35.9% preferred seasoned spinach with 0.5% MSG. Regarding the acceptance level of MSG, addition of MSG to improve taste was acceptable to the indifference type (cluster 1). On the contrary, active health action type did not prefer MSG, wanted natural seasonings despite high prices, and preferred to dine at restaurants that serve MSG-free foods. Based on this study, restaurant companies should segment their customers on the basis of MSG usage and establish their positioning strategies according to their concepts.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.4
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• pp.435-443
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• 2014

Purpose: The purpose of this study was to analyze the design identity visual elements of optical shop brand$\underline{s}$ in order to provide objective data necessary for optical shop brands' design development. Methods: This study examined the design identity concept of the optical shop brands and analyzed visual elements of brand design identity with a focus on the symbols of domestic franchise optical shops, type of a symbol mark, representation style of logo type, color usage, use or non-use of character, etc. Results: Many symbols were directly associated with the eyeglasses, such as eyeglasses and eyes, face and iris. Along with that, letters or figures were also observed. For the type of symbol, most types were found to have the designs that took spherical and word mark shapes. Particularly, the word mark type had English words more often than Korean words. For logo types, the gothic format was dominant. In relation to the thickness of letter, thick boldface type was commonly used. The combination of 2 degrees was the color frequency used most often in the optical shop brand design. For the frequency of color usage, black and red colors were used most often. Particularly, the orange color, as well as the black color, was also often used for the main color of symbols or logo types. Meanwhile, the characters were used only in some optical shop. Most characters were animals and expressed in the cartoon and graphical forms. Conclusions: Typifier, symbol mark, logo type, color, and character are the elements forming the basic development system for brand design identity. Systematic design is needed which clearly ensures the function and role along with the mutual consistency as a important visual component of the optical shop brand.