Multi-frame AR model을 이용한 LPC 계수 양자화

정원진,김무영,Jung, Won-Jin,Kim, Moo-Young 한국음향학회 2012 韓國音響學會誌 Vol.31 No.2

음성코딩 시 성도는 Linear Predictive Coding (LPC) 계수를 이용해서 모델링 한다. 일반적으로 LPC 계수는 양자화와 선형보간 관점에서 유리한 Line Spectral Frequency (LSF) 파라미터로 변경하여 사용한다. 10차 이상의 다차원 LSF 데이터를 벡터 양자화를 이용하여 직접 코딩하게 되면 벡터 내 상관관계 (intra-frame correlation)를 모두 이용할 수 있으므로 rate-distortion 관점에서는 높은 효율을 기대할 수 있다. 하지만, 계산량과 메모리 요구량이 높아져서 실제 코딩 시스템에서는 사용할 수 없게 되므로, 차원을 나누어 압축하는 Split Vector Quantization (SVQ)이 이용된다. 또한, LSF 데이터는 과거 벡터와의 벡터 간 상관관계 (inter-frame correlation)가 높으므로, 이를 이용한 Predictive Split Vector Quantization (PSVQ)이 사용되고 있다. PSVQ는 SVQ 보다 높은 rate-distortion 성능을 보인다. 본 논문에서는 음성 저장 장치를 위한 최적의 PSVQ를 구현하기 위해서 다수의 과거 프레임 정보와의 벡터 간상관관계 (inter-frame correlation)를 고려한 Multi-Frame AR-model 기반 SVQ (MF-AR-SVQ)를 제안하였다. 기존 PSVQ와 비교해 보았을 때, MF-AR-SVQ는 계산량과 메모리 요구량의 큰 증가 없이, 평균 spectral distortion 관점에서 약 1비트의 성능 향상을 보였다. For speech coding, a vocal tract is modeled using Linear Predictive Coding (LPC) coefficients. The LPC coefficients are typically transformed to Line Spectral Frequency (LSF) parameters which are advantageous for linear interpolation and quantization. If multidimensional LSF data are quantized directly using Vector-Quantization (VQ), high rate-distortion performance can be obtained by fully utilizing intra-frame correlation. In practice, since this direct VQ system cannot be used due to high computational complexity and memory requirement, Split VQ (SVQ) is used where a multidimensional vector is split into multilple sub-vectors for quantization. The LSF parameters also have high inter-frame correlation, and thus Predictive SVQ (PSVQ) is utilized. PSVQ provides better rate-distortion performance than SVQ. In this paper, to implement the optimal predictors in PSVQ for voice storage devices, we propose Multi-Frame AR-model based SVQ (MF-AR-SVQ) that considers the inter-frame correlations with multiple previous frames. Compared with conventional PSVQ, the proposed MF-AR-SVQ provides 1 bit gain in terms of spectral distortion without significant increase in complexity and memory requirement.

민족공동체의 구체적 전망으로서의 통일헌법-서울 향린교회

정원진 한신대학교 신학사상연구소 1994 신학사상 Vol.87 No.-

Effects of Mental Model and Intrinsic Motivation on Behavioral Intention of Smartphone Application Users

정원진,임형록 한국전자통신연구원 2016 ETRI Journal Vol.38 No.3

An application that has a simple user interface not only motivates a user to continue using the application, but also enables the user to develop their mental model for the application — the like of which is a product of their interaction with the application. In the information systems literature, little empirical research has been undertaken on the effects of the mental model and motivation on smartphone users’ behavioral beliefs. Therefore, the aim of this study is to suggest a research model that can examine the following: 1) the effects that the mental model has not only on smartphone users’ behavioral beliefs (that is, perceived usefulness and ease of use of an application) but also on their behavioral intention to use an application and 2) the effects that smartphone users’ intrinsic motivation has on their behavioral beliefs through an expansion of the mental model. A survey is conducted, and structural equation modeling is then used to analyze the survey data. The results, through consideration of variables such as intrinsic motivation, perceived usefulness, perceived ease of use, and user satisfaction, indicate that the mental model has an indirect effect on a user’s intention to use an application.

단체급식직원의 직무환경이 직무만족에 미치는 영향 - 코칭리더쉽을 매개효과 -

정원진,김경자,문석민 한국호텔리조트학회 2023 호텔리조트연구 Vol.22 No.3

This study investigated the relationship between the human environment, working environment, and job satisfaction, as well as whether coaching leadership plays a mediating role in this relationship. To achieve these aims, we conducted an empirical analysis based on previous studies and administered a sample survey to group meal workers. The survey was conducted over a 16-day period from October 15 to October 31, 2021. 300 copies of survey were distributed and analyzed 253 completed surveys. Our findings suggest that both the human and working environments have an impact on coaching leadership within the group catering service industry, and that the group catering service environment has an effect on job satisfaction. These results are statistically significant. Given the high reliance and dependence on the working environment and workforce in the group meal service industry, companies should strive to improve and develop their systems, including underdeveloped kitchens. Additionally, coaching leadership can contribute to achieving organizational goals by fostering a horizontal leadership culture in the workplace.

스마트폰 사용자가 지각한 모바일 쇼핑몰의 정보보안 수준이 쇼핑몰 이용의도에 미치는 영향

정원진,정석균 한국기업경영학회 2012 기업경영연구 Vol.19 No.4

As the use of computer and Internet in our daily lives continues to increase today, so do the computer crimes. Any illegal act involving a computer and Internet is referred to as computer crimes or cybercrimes. They also include unauthorized access and use, viruses and hackers, malwares and spywares, online theft and fraud, and other potential security and privacy problems. According to a study, millions of security incidents take place everyday and these incidents have a significant negative impact on the economy and society. Even some online activities with mobile devices such as mobile shopping can put users’ personal safety at risk. Regardless of wired or wireless, all computer and Internet users need to be aware of the security concerns. One of reasons smartphone users need to be aware of the security concerns when shopping online is that PC-based security methods may not be effective in smartphone settings. PCs and smartphones have totally different operating systems and hardware specifications. That means, PC-based security programs may not be compatible with the operating systems of smartphones. Because of this compatibility problem, many security programs running in PC-based Web pages frequently shows malfunctions in smartphone settings. When people face the failure of security systems, they hesitate or refuse to shop online. Thus, it is possible to infer that people will be likely to adopt mobile shopping depending on not only shopping malls’ real security level, but also their perceived security level. Based upon a comprehensive literature review, there has been little empirical research on the smartphone users’ perception of information security that may affect their intention to use mobile shopping malls. Therefore, the research goals of this study are to examine 1) the effects of smartphone users’ perceptions of information security on their intention to use mobile shopping malls and 2) the effects of two mediating variables, the satisfaction of service quality and the satisfaction of mobile shopping malls, between their antecedents and consequences. In order to collect data, a survey was conducted with university students and practitioners. Most measurement items for the latent variables were adapted from previous studies and some are modified to fit the context of this research. They are measured with a five-point Likert scale. The method employed for data analysis was Structural Equation Modeling (SEM) and the software used for the analysis was AMOS ver. 18. At first, the convergent and discriminant validities for all constructs were checked. The results of analysis showed that all constructs have adequate convergent and discriminant validities. The reliabilities of all constructs also reached the acceptable levels. The loadings of all items on their respective constructs were also quite high. Next, path coefficients were examined for the structural model. Smartphone users’ perceptions of information security was found to have an impact on the satisfaction of service quality (β =.261, p=.000). There was also an effect of the satisfaction of service quality on the satisfaction of mobile shopping malls (β =.655, p=.000). Finally, the results of analysis demonstrated that smartphone users’ intention to use mobile shopping malls was significantly influenced by the two variables, the satisfaction of service quality satisfaction (β =.330, p=.002) and the satisfaction of mobile shopping malls (β = .305, p=.003) respectively. Based upon the statistics above, all hypotheses were supported. In sum, the results implied that there is a relationship between smartphone users’ perceptions of information security and their intention to use mobile shopping malls. Another theoretical implication is that user satisfaction of service quality provided by mobile shopping malls was found to play as an important mediating variable as it was in previous studies. This study contributed to not only the validation o... 최근 스마트폰의 선풍적 인기에 힘입어 모바일 쇼핑 시장도 급속한 팽창이 예상되고 있다. 이러한장밋빛 전망에도 불구하고 모바일 쇼핑객의 쇼핑 만족도를 조사한 결과를 보면 정보보안에 대한 우려가 나타나고있다. 모바일 쇼핑객이 정보보안에 대해 우려를 갖게 되는 이유 중 하나는 PC 기반 보안시스템이 스마트폰에서는효과적이지 않을 수 있기 때문이다. 또한 모바일 기기에 특화된 쇼핑몰 웹 페이지를 이용하여 모바일 쇼핑을하거나, 혹은 스마트폰 기반의 모바일 쇼핑몰 애플리케이션을 설치하여 모바일 쇼핑을 할 경우에도 PC 환경에서의 보안 절차와 프로그램에 익숙한 사용자들은 이들과 다른 스마트폰 기반의 보안환경과 기술적 수준에대해 우려를 갖는다. 선행연구들에 대한 문헌조사에 의하면 스마트폰과 태블릿 PC같은 모바일 기기를 이용한쇼핑 시 정보보안을 포함한 서비스 품질이 쇼핑몰 만족도에 미치는 영향에 대한 연구는 다소 더디게 진행되고있다. 따라서 본 연구는 모바일 쇼핑객이 지각한 쇼핑몰의 정보보안 수준이 서비스 품질 만족도에 미치는 영향,그리고 서비스 품질 만족도가 쇼핑몰 만족도와 이용의도에 미치는 영향을 실증적으로 탐구해 보고자 하는데연구목적을 두고 있다. 최근 스마트폰을 이용하여 모바일 쇼핑몰을 방문한 경험이 있는 쇼핑객을 대상으로설문을 실시한 후 구조방정식을 이용하여 자료를 분석하였다. 분석 결과 모바일 쇼핑객의 지각된 정보보안수준이 서비스 품질 만족도와 쇼핑몰 만족도를 매개로 쇼핑몰 이용의도에 많은 영향을 미치고 있음을 확인할 수 있었다.

상황 데이터 품질의 의사결정 성과에 미치는 영향

정원진,김종원 한국경영정보학회 2005 Asia Pacific Journal of Information Systems Vol.15 No.3

Data Warehousing, Contextual Data Quality, and Problem Solving Performance

정원진 한국정보시스템학회 2005 情報시스템硏究 Vol.14 No.2

샬롬-"부활을 살자"

정원진 우리신학연구소 1997 갈라진 시대의 기쁜소식 Vol.- No.282

샬롬-성숙한 유일신앙

정원진 우리신학연구소 1997 갈라진 시대의 기쁜소식 Vol.- No.277

한국 청소년의 복부비만과 관련된 생활습관

정원진,조영규,강재헌,박현아,김경우,강주호,김누리,김혜진,김옥현 대한가정의학회 2010 Korean Journal of Family Medicine Vol.31 No.7

Background: It has been reported that the abdominal obesity can cause various metabolic abnormalities not only in adults but also in adolescents. This study was conducted to investigate lifestyle habits related to abdominal obesity in Korean adolescents. Methods: This study is a cross-sectional study on 561 adolescents (305 boys and 256 girls) aged 12-18 years from the Korean National Health and Nutrition Examination Survey 2005. The abdominal obesity was defined as waist circumference at or above the 90th percentile for each age and gender based on the 2007 growth chart for Korean children. The frequency of physical activity, screen time, and the intake amount of energy and macronutrients were investigated as lifestyle habits. Results: The prevalence of abdominal obesity in Korean adolescents aged 12-18 years was 9.1% (Boys, 9.4%; Girls, 8.7%). The mean of daily screen time was 4.3 ± 0.1 hours (Boys, 4.4 ± 0.2 hours; Girls, 4.2 ± 0.2 hours). The subjects with daily screen time ≥ 5 hours had a 3.0 times increased risk of abdominal obesity compared to subjects with daily screen time < 3 hours (P-value = 0.004). The adjusted odds ratio of fat intake ≥ 35% of energy was 2.57 (95% confidence interval, 1.16to 5.68; P-value = 0.020) with fat intake < 25% of energy as reference. The relationship between long screen time and abdominal obesity was observed in girls and high fat intake was related to abdominal obesity in boys. Conclusion: This study shows that abdominal obesity in Korean adolescents is associated to long screen time and high fat intake. 연구배경: 복부비만은 성인 뿐 아니라 청소년에서도 대사장애의 위험을 증가시키는 것으로 알려졌다. 그러나 청소년의복부비만의 원인 및 관련 요인에 대한 연구 결과는 거의 보고되지 않았다. 본 연구는 청소년의 복부비만과 관련 있는 생활습관을 알아보기 위해 수행되었다. 방법: 본 연구는 2005년 국민건강영양조사에 참여한 만12-18세 청소년 561명(남아, 305명; 여아, 256명)을 대상으로한 단면연구이다. 2007년 소아 청소년 표준 성장도표를 참조하여, 성별 연령별 허리둘레 90백분위수 이상을 복부비만으로 진단하였고, 청소년의 생활습관으로 신체활동 빈도, screen time, 에너지 및 다량 영양소 섭취량을 조사하였다. 결과: 청소년의 복부비만 유병률은 9.1% (남아, 9.4%; 여아,8.7%)이었다. 청소년의 하루 평균 screen time은 4.3±0.1시간(남아, 4.4±0.2시간; 여아, 4.2±0.2시간)이었으며, 단백질, 지방, 탄수화물의 에너지 구성비는 각각 14.8±0.2%, 23.8±0.4%, 61.4±0.5%이었다. Screen time이 5시간 이상인 청소년은 3시간 미만인 청소년에 비해 복부비만으로 진단될 가능성이 약 3배 높았으며(P-value=0.004), 지방의 에너지 섭취 비율이 35.0% 이상인청소년은 25.0% 미만인 청소년에 비해 복부비만의 유병률이약 2.6배 높았다(P-value=0.020). 남아와 여아를 나누어 분석한결과, 긴 screen time은 여아에서, 지방의 에너지 섭취 비율 증가는 남아에서 복부비만과의 관련성이 컸다. 결론: 본 연구는 청소년의 복부비만이 긴 screen time 및 고지방식과 관련이 있음을 제시하였다. 향후 효과적인 근거 중심의 소아비만 관리 프로그램의 실행을 위해서는 본 연구의 결과가 고려되어야 할 것이다.