• The Journal of the Acoustical Society of Korea
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• v.29 no.1
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• pp.62-68
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• 2010

This paper proposes a new masking threshold adjustment strategy to improve the performance for speech signals in low bit-rate audio coding. After determining formant regions, the masking threshold is adjusted by using the energy ratio of each sub-band to the average energy of each formant. More quantization noises are added to the bands that have relatively large energy, but less distortion is allowed in spectral valley regions by allocating more bits, which reflects the concept of perceptual weighting widely used in speech coding. From the results of objective speech quality measure, we verified that the proposed method improves quality for the speech input signals compared to the conventional one.

• Phonetics and Speech Sciences
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• v.12 no.1
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• pp.11-17
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• 2020

Non-tonal language speakers may have difficulty learning second language lexical tones. In the present study, we explored this issue with Korean-speaking learners of Mandarin Chinese (i.e., non-tonal first language speakers) by examining their perception and production of Mandarin lexical tones. In the perception experiment, the Korean learners were asked to listen to the tone of each stimulus and assign it to one of four Mandarin lexical tones using the response keys; in the production experiment, the learners provided speech production data for the lexical tones and then their productions were identified by native listeners of Mandarin Chinese. Our results showed that the Korean learners of Mandarin Chinese had difficulty in perceptually distinguishing Tone 2 and Tone 3, with the most frequent production error being the mispronunciation of Tone 3 as Tone 2. We also investigated whether unfamiliar non-native phonemes (i.e., Chinese phonemes) that do not exist in the native language phonemic inventory (i.e., Korean) may hinder the processing of the non-native lexical tones. We found no evidence for such effects, neither for the perception nor for the production of the tones.

• Journal of Broadcast Engineering
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• v.21 no.6
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• pp.920-928
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• 2016

Recently high dynamic range imaging technique is hot issue in computer graphic area. We present a progressive tone mapping algorithm, which is based on weighted least squares optimization framework. Our approach combines weighted least squares filtering with iCAM06 model. To show more perceptual high dynamic range images in conventional display, we decompose high dynamic range image into base layers and detail layers. The base layers are obtained by using weighted least squares filter. Then, we adopt chromatic adaption function and non-linear compression function to deal with base layers. Only the base layers reduce contrast, and preserving detail. The image quality assessment shows that our tone mapped image is more similar to original high dynamic range image. Moreover, the subjective result shows our algorithm produces more reliable and pleasing image.

• Proceedings of the Korean Society for Quality Management Conference
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• 2006.04a
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• pp.3-7
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• 2006

현대 기업은 경영 전략의 방향 및 평가를 위하여 고객만족도를 조사한다. 특히 서비스업에서는 많은 경우 SERVQUAL 점수를 이용하여 고객만족도를 평가한다 SERVQUAL은 고객의 기대와 지각의 차이를 조사하여 고객만족도를 평가하며 22 개의 평가항목은 5가지의 품절특성 (유형성, 신뢰성, 대응성, 확신성 공감성)에 대한 SERVQUAL 접수로 산출된다. WSERVQUAL 접수는 SERVQUAL 점수에 단순평균방식과 상대적 중요도를 가중한 가중접수로 계산되는 방법으로 상대적 중요도를 파악하기 위하여 기존에서는 중요도에 대한 고객의 의견을 파악하여 적용하였으나 본 논문에서는 임성욱의 잠재적 고객만족 개선지수 (PCSI Index)를 적용하여 고객의 향후 잠재적 만족개선정도에 관한 내용을 포함한 가중치를 산정할 수 있는 방법론을 제시하였다.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.6 no.1
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• pp.1-12
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• 2001

Tidal computations of $M_2,\;S_2,\; K_1$ and $O_1$ constituents in the northeast Asian sea are presented by blending the Topex/Poseidon (T/P) altimeter data into a hydrodynamic model with $5'{\times}5'$ resolution. A series of sensitivity experiments on a weighting factor, which is the control parameter in the blending method, are carried out using $M_2$ constituent. The weighting factor is set to be in inverse proportion to the square root of water depth to reduce noises which could occur in data-assimilative model by blending T/P data. Model results obtained by blending the T/P-derived $M_2,\;S_2,\; K_1$ and $O_1$ constituents simultaneously are compared with all T/P-track tidal data; Average values of amplitude and phase errors are close to zero. Standard deviations of amplitude and phase errors are approximately 2 cm and less than 10 degrees respectively. The data-assimilative model results show a quite good agreement with T/P-derived tidal data, particularly in shallow water region (h<250m). In deep water regions, T/P-derived tidal data show unreasonable spatial variations in amplitude and phase. The data-assimilative model results differ from T/P-derived data, but are improved to show reasonable spatial variations in amplitude and phase. In addition, the T/P-blended model results are in good agreement with coastal tide gauge data which are not blended into the model.

• 한국벤처창업학회:학술대회논문집
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• 2021.11a
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• pp.189-195
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• 2021

최근 고령화로 인한 수명연장은 노후생활비용 부담의 가중을 통해 고령자들의 노후파산 가능성을 높이는 핵심 위협요인이 되고 있기 때문에 이를 위한 사적자산의 안정적, 장기적인 관리와 증식이 필수적이다. 자산관리 자문/일임 서비스를 이용하는 것은 이를 해결할 수 있는 좋은 대안이지만 과거에는 서비스 이용가능 대상이 대형 금융기관을 거래하는 거액자산가들로 국한되어 있었다. 그런데 최근 기술혁신과 더불어 플랫폼을 기반으로 하는 웰스테크(디지털 자산관리) 서비스가 빠른 속도로 대중화되고 있어, 이를 활용하면 보다 많은 고령자들이 자산관리에 대한 부담을 경감할 수 있을 것으로 예상된다. 본 연구에서는 이런 이유로 최근 주목받는 웰스테크(디지털 자산관리) 자문/일임 서비스에 대한 고령자들의 사용의도에 영향을 미치는 특성 및 요인들을 파악하고자 한다. 이를 위해 기술수용이론 중 소비자가 얻는 혜택과 희생을 모두 고려하는 '가치기반수용모델(Value Based Model)'을 기본 모형으로 하되 웰스테크(디지털 자산관리) 자문/일임서비스의 특성을 고려하여 '가격효용성'을 혜택 요인에 추가하였다. 또한 고령자의 특성을 고려하여 희생 요인에 '인지된 위험'을, 별도의 요인으로 '사회적 영향'을 각각 추가하였다. 예상되는 연구결과로는 지각된 혜택에 해당하는 유용성, 즐거움, 가격효용성은 모두 인지된 가치에 유의한 (+)의 영향을 미칠 것으로 예상되는 반면, 지각된 희생에 해당하는 기술성과 인지된 위험은 모두 인지된 가치에 유의한 (-)의 영향을 미칠 것으로 예상된다. 또한 추가변수인 사회적 영향은 인지된 가치에 유의한 (+)의 영향을 미칠 것으로 예상된다.

• Journal of Radiation Protection and Research
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• v.15 no.2
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• pp.87-100
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• 1990

For the quantitative evaluation and assessment of radiation exposure from terrestrial component of natural environmental radiation, successive thermoluminescence dosimetry and periodical in-situ gamma ray spectrometry were carried out for a period of 24 months. LiF PTFE dise TLDs and $3&{\phi}{\times}3'$cylindrical NaI(Tl)scintill ation detector in association of portable multichannel analyzer (4096 ch) were used in this study. The doses measured were evaluated and assessed in terms of effective dose equivalent. As a concomitant output, the dose equivalent due to ionizing component of cosmic ray was able to be evaluated. According to the results obtained in terms of variance weighted mean, the annual effective dose equivalents of terrestrial gamma ray and cosmic ray ionizing component in Taejeon area came out to be $564{\pm}4\;{\mu}Sv(64.8{\pm}0.5nSv{\cdot}h^{-1}$ and $300{\pm}2\;{\mu}Sv(34.3{\pm}0.2nSv{\cdot}h^{-1}$, respectively, which are reasonable comparably with that appeared in UNSCEAR Report[28]as per caput annual effective dose equivalent in 'areas of normal background radiation'.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.793-795
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• 2007

The present study investigates the effect of the flight path of military aircraft on noise map and its WECPNL distribution. Aircraft noise modeling and simulation are made on a Korean military airport by INM(Integrated Noise Model) 6.2 version, and the flight path of military aircraft is modeled by combining takeoff, overfly, approach and touch-and-go modes. The present INM simulations are conducted for two cases with different overfly modes and show that the change of overfly mode remarkably affects the noise influence region and the WECPNL distribution around the aircraft.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.604-608
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• 2007

The INM simulation program is used to estimate the condition of the exposed area to the noise near a military airport in Korea. $WECPNL_k$, the evaluation unit of korean airport noise, is different from the ICAO $WECPNL_I$ that is used in the simulation program. Therefore, it is inappropriate to compare these units each other directly. This study presents method of comparison between them by using $LA_{MAX}$. The aircraft events are classified into three classes, as departure, overfly and approach. In result, the measurement and simulation seemed to be similar at departure and approach pattern. However, overfly pattern had higher errors between measurement and simulation. Finally, it is necessary to examine the method to determine flight events and duration for the $WECPNL_k$ application.

• Korean Institute of Interior Design Journal
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• v.24 no.2
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• pp.108-116
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• 2015

The probability of visual perception occurrence varies in case the expectation of using each unit space of which the whole space consists because the size of space subject to analysis is very large or the organization is complicated in the analysis of spatial visual configuration. Therefore, it is necessary to compensate space analysis and index measurement by applying weight to the point of view for the probability of experiencing space. This study proposed a method of analyzing visibility ratio by applying the integration of space syntax theory as weight, and grasped the effect in comparison with the visibility ratio when weight was not applied.