• Speech Sciences
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• v.7 no.1
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• pp.17-29
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• 2000

The STC(Sinusoidal Transform Coding) is a vocoding technique that uses a sinusoidal speech model to obtain high- quality speech at low data rate. It models and synthesizes the speech signal with fundamental frequency and its harmonic elements in frequency domain. To reduce the data rate, it is necessary to represent the sinusoidal amplitudes and phases with as small number of peaks as possible while maintaining the speech quality. As a basic research to develop a low-rate speech coding algorithm using the sinusoidal model, in this paper, we investigate the speech quality depending on the number of sinusoids. By varying the number of spectral peaks from 5 to 40 speech signals are reconstructed, and then their qualities are evaluated using spectral envelope distortion measure and MOS(Mean Opinion Score). Two approaches are used to obtain the spectral peaks: one is a conventional STFT (Short-Time Fourier Transform), and the other is a multiresolutional analysis method.

• Journal of Astronomy and Space Sciences
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• v.19 no.4
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• pp.255-262
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• 2002

We present the infrared spectra of Herbig Ae/Be stars including the Infrared Space Ob-servatory (ISO) data. To investigate the overall properties of their circumstellar dust envelope and/or disk, we combine the IR spectra with photometric data ranging from the UV through the optical into the sub-mm region. We study the general characteristics of the spectral energy distributions using simple analysis. We plot the positions on the HR-diagram to compare with the theoretical pre-main-sequence evolution tracks.

• Asia Marketing Journal
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• v.20 no.1
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• pp.1-21
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• 2018

An increasing number of studies have examined the effects of corporate social responsibility (CSR) activities on corporate financial performance (CFP) in the service industry. However, the extant literature does not provide comprehensive insights into the conditions on which the CSR-CFP link relies. In this study, firms' marketing communication capability (MCC) is introduced as an important contingency variable, which determines the effects of CSR on the corporate financial performance, in the context of restaurant businesses. Multiple year data on the spending of public restaurant chains on different media are collected, and MCC is subsequently measured using the data envelope analysis. Then, a test is conducted to prove whether MCC moderates the relationship between CSR and firm financial performance. The empirical results support the hypothesis that MCC strengthens the effect of CSR on CFP. Through the findings, this research provides several interesting and important implications to the literature and managers of service firms.

• 지역과문화
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• v.6 no.2
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• pp.77-104
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• 2019

This study examines the efficiency of using local cultural resources in local governments. The study does so by DEA(Data Envelope Analysis) using data from the year 2017 for 17 local governments in Korea. In addition, this study tries to estimate environmental efficiency of local cultural resources. For this, the 'Total Efficiency' including the output variables related to the local cultural resource environment was analyzed. After than It compared the 'Total Efficiency' with the 'Utilization Efficiency', to estimate the 'Environmental Efficiency' of local cultural resources. The followings are results which are significant statistically. Firstly, it was evaluated that five of the 17 local governments utilized the local cultural resources efficiently. Secondly, it was result that the inefficiency of the other local governments was relatively influenced by the economies of scale than PTE(Pure Technical Efficiency). Thirdly, It has been confirmed that environmental aspects such as cultural properties and cultural infrastructure have a considerable impact on the increase or decrease of efficiency in local governments. The difference in the efficiency of local governments are influenced by the population density. In order to improve the efficiency in the future, it is necessary to adjust the appropriate level of input according to the local population estimate, which is a major consumer of the local cultural resource utilization. In addition, the local festivals and village festivals held by local governments should be checked to improve in quality by eliminating inefficiencies. Also, it should be considered of environmental factors together, when analyzing the efficiency of the local cultural resource in local governments.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.2
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• pp.258-266
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• 2012

Recently, Acoustic Emission (AE) technique is widely applied to develop the early fault detection system, and the problem about a signal processing method for AE signal is mainly focused on. In the signal processing method, envelope analysis is a useful method to evaluate the rolling element bearing problems and Wavelet transform is a powerful method to detect faults occurred on gearboxes. However, exact method for AE signal is not developed yet. Therefore, in this paper, two methods, which is Hilbert transforms (HT) and Hilbert-Huang transforms (HHT), will be compared for development a signal processing method for early fault detection system by using AE. AE signals were measured through a fatigue test. HHT has better advantages than HT because HHT can show the time-frequency domain result. But, HHT needs long time to process a signal, which has a lot of data, and has a disadvantage in de-noising filter.

• Industry Promotion Research
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• v.7 no.2
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• pp.1-13
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• 2022

This study of purpose is to examine the efficiency through the current status and performance of each institution providing the Daegu community service investment project, and to find a direction for the efficient operation of each institution. In order to promote efficient and effective project promotion by checking the management status that meets the purpose of the local community service investment project, to provide systematic services necessary to consumers, improve quality, and improve the environment, the accurate situation and situation through the efficiency analysis of the service provider organization It is necessary to identify problems, develop programs suitable for regional characteristics, and actively manage services. Specifically, it seeks to provide a more stable and sustainable local community service by measuring efficiency based on information from each institution and comparing and analyzing it among local governments. For this purpose, it is meaningful in analyzing the efficiency of each institution by using the DEA (data envelope analysis) method and presenting the goals and policy implications for efficient operation by comparing them by local government.

• Proceedings of the KSME Conference
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• 2001.06b
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• pp.392-397
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• 2001

This paper concerns on modal analysis of mechanical structures by using a continuous scanning laser Doppler vibrometer. In modal analysis the Hilbert transform based approach is superior to the Fourier transform based approach because of its fine accuracy and its flexible experimental settings. In this paper the Hilbert transform based approach is extended to measure area mode shape data of a structure by simply modifying the scanning pattern ranging the entire surface of the structure. The effectiveness of this proposed method is illustrated along with results of numerical simulation for a rectangular plate.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.4
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• pp.91-99
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• 2005

Flight compatibility certification is performed to substantiate the compatibility between ALQ-X ECM pod and KF-16D/RF-4C aircraft. A certification plan for the ALQ-X flight compatibility is established. Similarity analysis, mass/inertia analysis, structural analysis/test, and ground vibration test/flutter analysis are made to support the safety of MIL-HDBK-1763 Test 250 (Captive compatibility flight profile). Aircraft flew along flight envelope boundary with representative ALQ-X configurations. Handling qualities are evaluated by comparing flight characteristics of the aircraft with and without ALQ-X. Structural integrity and endurance is evaluated using measured flight test data. Results of these flight tests showed that ALQ-X is compatible with KF-16D/RF-4C without altering the flight envelope which has originally been certified for ALQ-88 and ALQ-119 ECM pods. ALQ-X certification program made following technical achievements: Type III certification for foreign designed fighter, flutter analysis program development using GVT results, and utilization of MIL-STD-1553B data bus in flight test.

• Asia-Pacific Journal of Business
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• v.9 no.3
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• pp.51-69
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• 2018

This study intends to investigate the management efficiency of social enterprises according to types based on the portion of the budget for employing disadvantaged social groups, in the region of Gyeonggi-do. Based on the performance list disclosed at Korea Social Enterprise Promotion Agency's website, 126 social enterprises certified during a period of five years from 2013 to 2017, 126 enterprises were analyzed by using data envelopment analysis (DEA) models comparing five types of the enterprises. The types was mainly identified by the job security of disadvantaged social groups. As for measurement variables, the input components included average wage, support fund, and the number of non-vulnerable employees and the number of vulnerable employees, sales, and net income were selected as output variables. In conclusion, the efficiency of Gyeonggi-do social enterprises decreased every year, and thus it is urgent to improve their efficiency, and priority should be given to the employment of vulnerable social groups, which both the job opportunity providing-type and the social service providing-type showed the highest performance.

• Physical Therapy Korea
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• v.13 no.1
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• pp.54-60
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• 2006

This study aimed to compare movement patterns of shoulder joints between the right and left symmetry in stroke patients and control subjects. This study proposes use of the voluntary response index (VRI) calculated from quantitative analysis of surface electromyographic (sEMG) and motion data recorded during voluntary movement as a feeding task. The VRI is comprised of two numeric values, one derived from the total muscle activity recorded for the voluntary motor task (magnitude), and the other from the sEMG distribution across the recorded muscles with the similarity index (SI). Five stroke patients and five age-matched healthy controls were recruited. Feeding motion was performed using the provided spoon five times with rests taken on a chair in between tasks. EMG data were digitized and analyzed on the basis of the root mean square (RMS) envelope of activity. The average amplitude of responses was calculated. Responsiveness and clinically meaningful levels of discrimination between stroke patients and control for EMG magnitude and SI were determined. The similarity index of the results from two successive examinations of both sides apart for stroke patients and control subjects were .86 and .95 in motion analysis and .84 and .99 in electromyographic analysis. The SI of sEMG data and motion data was significantly correlated in stroke patients. The data suggest that SI is a sensitive program for comparing and analyzing the symmetry of muscle activity and motion in both sides. This analysis method has a clinical value in grading muscular activity and movement impairment after brain injury.