• Journal of the Korean Society for Aviation and Aeronautics
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• v.17 no.3
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• pp.1-6
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• 2009

Since the success of the first flight, vast advancements have been made to the aircrafts with recent developments incorporating highly complex mechanisms, placing greater emphasis on the competence of the pilot. Studies are currently being undertaken to effectively source the trainee pilots with the most ideal level of aptitude for aviation with an aim to optimise the selection process with focus on economy and time, while research into identifying the optimal human characteristics for aviation is being done. As part of the selection process, number of tests is arranged with focus on the individual competence, suitability for flight, health status, aptitude and intelligence with the results of the tests used as reference materials during the selection procedure. This study has investigated the effect the academic competence has on the aptitude for aviation amongst many other abilities of human beings and the findings show that higher levels of aptitude have been demonstrated by the students who have displayed academic excellence across all the courses with statistics pointing to a positive correlation between the two subjects. This supports the theory that students who are academically superior have higher probability of being found to possess greater level of flight aptitude. The outcome of the study iterates the fact that academic competence of the students should not be regarded lightly in the selection process. Based on the current study, it is believed that a research into determining the relationship between the SAT results, average yearly grade and flight aptitude will help identify the key factors in possessing high level of flight aptitude with greater certainty.

• Journal of Fashion Business
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• v.10 no.3
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• pp.87-99
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• 2006

For comprehending the duties of fashion designer, Sharon(1989) has suggested to look at the procedure how the goods are being produced. The purpose of this research is to identify the task of domestic fashion designer by comparing and analyzing one's work range and performing level in the fashion merchandising process according to the brand types which one is involved in. The preliminary research for the questionnaire was conducted with 5 chief designers of woman's apparel manufactures in Seoul. They were asked to judge if designer's tasks fit to their carry-out operations in the pre-fixed questionnaire which had been done based on preliminary researches and literatures related with fashion merchandising process. The contents of research questionnaire are 11 questions to understand the general characteristics of companies and the participated subjects, and 42 questions to understand the designers' operations. For the selection of NB, among 503 domestic female apparel brands that were in 'Korean Textile Fashion yearbook (2002-2003), the companies that were located in Seoul and possible for cooperation by researcher's personal relationship were selected. For DB, cooperation was requested for brands that were located in Seoul among the 137 brands that participates on Domestic Collection. For GB, 50 stores were selected at random or by personal relationship among 32 GB shops such as Freya Town, Doosan Tower, New Zone, and so on. Total 300 questionnaire distributed to the designers, 192 copies were used for final data analysis. For data analysis, descriptive statistics and ANOVA, Sceffe test were used using SPSS V. 11 1. The participated fashion designers operated 41 categories of suggested 42 categories in the fashion merchandising process. 2. The ranges and contents of tasks in the fashion merchandising process that fashion designers mainly carry-out are very different according to the brand types and showed much different level of task carry-out. Only in the categories of 'fashion trend information' and 'design ideation', all three brand type showed the highest level of task performance. And the design related tasks presented common higher level of performance than the other tasks in all brand types. In order to comprehend the operation of fashion designer, various approaching methods are required according to various apparel manufactures' characteristics.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.4
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• pp.313-322
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• 2003

In this paper, the reverse link performance of imperfect power controlled cdma2000 cellular system that using array at a base station is analyzed, when MCGM beamforming algorithm and power control error is considered in shadowing. The blocking probability of the cdma2000 cellular system based on array parameters, E$\_$b//N$\_$0/ and interference statistics is calculated, and then the system capacity is calculated at a specific blocking probability. When the blocking probability is set 1 %, PCE(power control error) is 2 dB, M=2, 4, 8, 10, the capacity of cdma2000 is increased 2.3 ∼ 2.5 times higher than IS-95.

• YAKHAK HOEJI
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• v.52 no.6
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• pp.507-513
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• 2008

The purpose of this study is to analyze the factors affecting financial performance of community pharmacies after the implementation of the new drug policy in Korea: separation of drug prescription and dispensing (SPD). The online survey questionnaires were sent to the active pharmacists of the total 20,633 community pharmacies in Korea and 1,147 pharmacists responded to the survey (the response rate was 5.5%). The questionnaire asked simple financial data in order to compare their financial performances before and after the policy. With the SPSS package (version 12.0), two levels of data analysis were used: 1) descriptive statistics to see the financial status of the pharmacies; and 2) multiple regression analysis to find the factors. {or A multiple regression method was used for the data analysis.} The finding illustrated that the average net benefit of the pharmacies was 4,870 thousand won in August 2006, and the major factors affecting the net benefit were the location of pharmacy (geographical proximity to medical institutions), number of prescriptions, drug management services for patients, chain pharmacy membership. The findings of this study suggest that service improvement for patients, revitalization of non-prescription drug sales, professional management will contribute to promote community based pharmacy business.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.38 no.4
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• pp.1-10
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• 2001

The 3-step cell search has been considered for fast acquisition of the scrambling code unique to a cell in the W -CDMA system. In this paper, the performance of the cell search scheme is analyzed in Rayleigh fading channels. And the system parameters for cell search scheme and the design parameters for the receivers are examined. The probabilities of detection, miss and false alarm for each step are derived in closed forms based on the statistics of CDMA noncoherent demodulator output. Through the analysis, the effect of threshold setting and post detection integration for each step is investigated, and the optimal values of the power allocation for the synchronization channels are also considered. The number of post-detection integrations for each step is a design parameter for the receiver, and the optimum values may depend on not only the power allocation for each channel related to the cell search, but the false alarm penalty time. It is shown that optimal values could be determined through the analysis. Also, the cumulative probability distribution of the average cell search time is obtained.

• Journal of Communications and Networks
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• v.18 no.3
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• pp.387-396
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• 2016

Multiuser communication has been an important research area of underwater acoustic communications and networking. This paper studies the use of adaptive orthogonal frequency-division multiple access (OFDMA) in a downlink scenario, where a central node sends data to multiple distributed nodes simultaneously. In practical implementations, the instantaneous channel state information (CSI) cannot be perfectly known by the central node in time-varying underwater acoustic (UWA) channels, due to the long propagation delays resulting from the low sound speed. In this paper, we explore the CSI feedback for resource allocation. An adaptive power-bit loading algorithm is presented, which assigns subcarriers to different users and allocates power and bits to each subcarrier, aiming to minimize the bit error rate (BER) under power and throughput constraints. Simulation results show considerable performance gains due to adaptive subcarrier allocation and further improvement through power and bit loading, as compared to the non-adaptive interleave subcarrier allocation scheme. In a lake experiment, channel feedback reduction is implemented through subcarrier clustering and uniform quantization. Although the performance gains are not as large as expected, experiment results confirm that adaptive subcarrier allocation schemes based on delayed channel feedback or long term statistics outperform the interleave subcarrier allocation scheme.

• The KIPS Transactions:PartD
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• v.14D no.5
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• pp.459-470
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• 2007

A data stream is a massive unbounded sequence of data elements continuously generated at a rapid rate. Query processing for such a data stream should also be continuous and rapid, which requires strict time and space constraints. In most DSMS(Data Stream Management System), the selection predicates of continuous queries are grouped or indexed to guarantee these constraints. This paper proposes a new scheme tailed an ASC(Attribute Selection Construct) that collectively evaluates selection predicates containing the same attribute in multiple continuous queries. An ASC contains valuable information, such as attribute usage status, partially pre calculated matching results and selectivity statistics for its multiple selection predicates. The processing order of those ASC's that are corresponding to the attributes of a base data stream can significantly influence the overall performance of multiple query evaluation. Consequently, a method of establishing an efficient evaluation order of multiple ASC's is also proposed. Finally, the performance of the proposed method is analyzed by a series of experiments to identify its various characteristics.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.5897-5905
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• 2015

This paper investigates the differentials in productivity and growth performance between small and medium size and large size firms in Korean manufacturing industries. According to the empirical analysis based on the Mining and Manufacturing Survey of Statistics Korea, this paper finds the following facts. First, the level of contribution of capital deepening on the growth rate of output(value added) is relatively greater in the small and medium size firm group, while the level of contribution of total factor productivity on the growth rate is relatively greater in the large size firm group. Second, the productivity polarization among the firms has increased relatively greater in the large size firm group over the past decade.

• Journal of IKEEE
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• v.22 no.4
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• pp.953-958
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• 2018

In this study, a portable detection system was developed that can detect harmful gas and signals simultaneously in an enclosed space of industrial sites and underground facilities. The developed system is a sensor module for gas detection, a patch type 1 channel small ECG sensor, a module for three-axial acceleration detection sensor, and a system for statistics. In order to verify the performance of the system modules, the digital resolution, signal frequency, output voltage, and ultra-small modules were evaluated. As a result of the performance of the developed system, the digital resolution was 300 (rps) and the signal amplification gain was 500 dB or more, and the ECG module was manufactured with $50mm{\times}10mm{\times}10mm$ to increase patch utilization. It is believed that the product of this research will be valuable if it is used as an IoT-based management system for real-time monitoring of industrial workers.

• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.1
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• pp.51-63
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• 2022

Up-to-date statistics of crop cultivation status is essential for farm land management planning and the advancement in remote sensing technology allows for rapid update of farming information. The objective of this study was to develop a classification model of rice paddy or winter crop fields based on NDWI, NDVI, and HSV indices using Sentinel-2 satellite images. The 18 locations in central Korea were selected as target areas and photographed once for each during summer and winter with a eBee drone to identify ground truth crop cultivation. The NDWI was used to classify summer paddy fields, while the NDVI and HSV were used and compared in identification of winter crop cultivation areas. The summer paddy field classification with the criteria of -0.195