• Title/Summary/Keyword: performance enhancement

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Analyzing The Types of Policy Support Used by Venture-Backed Startups (벤처투자를 유치한 창업 기업의 정책지원 이용 유형 분석)

  • Jaesung James Park
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.18 no.4
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    • pp.177-191
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    • 2023
  • This study analyzes the types of linkages between major projects used by firms that attracted venture capital among firms that received government support in the field of SME startups. It identifies the types of linkages between support programs related to attracting venture investment and verifies the usefulness of integrated and cooperative support. The main findings of this study are as follows. First, Startup Success Packages, Startup Foundation Funds*, Youth Entrepreneurship Centers, and Training are the main programs used by startups and venture firms, and support-implementing agencies use these programs to provide support for each stage of growth. Second, the majority of startups and venture firms receiving policy support for job creation and manpower enhancement projects. Third, export-type growth companies receive continuous support from MSS, MOTIE, MSIT, and KIPO. Fourth, job creation programs drive the employment performance and creation of companies. Fifth, local government support projects tend to rely heavily on central government support programs. Sixth, growth companies in the startup and venture sector have a clear link to credit guarantee scheme by KIBO. These findings provide empirical evidence on the necessity and feasibility of integrated and collaborative support, and are expected to contribute to the direction of better support policies.

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A study on the application of residual vector quantization for vector quantized-variational autoencoder-based foley sound generation model (벡터 양자화 변분 오토인코더 기반의 폴리 음향 생성 모델을 위한 잔여 벡터 양자화 적용 연구)

  • Seokjin Lee
    • The Journal of the Acoustical Society of Korea
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    • v.43 no.2
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    • pp.243-252
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    • 2024
  • Among the Foley sound generation models that have recently begun to be studied, a sound generation technique using the Vector Quantized-Variational AutoEncoder (VQ-VAE) structure and generation model such as Pixelsnail are one of the important research subjects. On the other hand, in the field of deep learning-based acoustic signal compression, residual vector quantization technology is reported to be more suitable than the conventional VQ-VAE structure. Therefore, in this paper, we aim to study whether residual vector quantization technology can be effectively applied to the Foley sound generation. In order to tackle the problem, this paper applies the residual vector quantization technique to the conventional VQ-VAE-based Foley sound generation model, and in particular, derives a model that is compatible with the existing models such as Pixelsnail and does not increase computational resource consumption. In order to evaluate the model, an experiment was conducted using DCASE2023 Task7 data. The results show that the proposed model enhances about 0.3 of the Fréchet audio distance. Unfortunately, the performance enhancement was limited, which is believed to be due to the decrease in the resolution of time-frequency domains in order to do not increase consumption of the computational resources.

Targetoid Primary Liver Malignancy in Chronic Liver Disease: Prediction of Postoperative Survival Using Preoperative MRI Findings and Clinical Factors

  • So Hyun Park;Subin Heo;Bohyun Kim;Jungbok Lee;Ho Joong Choi;Pil Soo Sung;Joon-Il Choi
    • Korean Journal of Radiology
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    • v.24 no.3
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    • pp.190-203
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    • 2023
  • Objective: We aimed to assess and validate the radiologic and clinical factors that were associated with recurrence and survival after curative surgery for heterogeneous targetoid primary liver malignancies in patients with chronic liver disease and to develop scoring systems for risk stratification. Materials and Methods: This multicenter retrospective study included 197 consecutive patients with chronic liver disease who had a single targetoid primary liver malignancy (142 hepatocellular carcinomas, 37 cholangiocarcinomas, 17 combined hepatocellular carcinoma-cholangiocarcinomas, and one neuroendocrine carcinoma) identified on preoperative gadoxetic acid-enhanced MRI and subsequently surgically removed between 2010 and 2017. Of these, 120 patients constituted the development cohort, and 77 patients from separate institution served as an external validation cohort. Factors associated with recurrence-free survival (RFS) and overall survival (OS) were identified using a Cox proportional hazards analysis, and risk scores were developed. The discriminatory power of the risk scores in the external validation cohort was evaluated using the Harrell C-index. The Kaplan-Meier curves were used to estimate RFS and OS for the different risk-score groups. Results: In RFS model 1, which eliminated features exclusively accessible on the hepatobiliary phase (HBP), tumor size of 2-5 cm or > 5 cm, and thin-rim arterial phase hyperenhancement (APHE) were included. In RFS model 2, tumors with a size of > 5 cm, tumor in vein (TIV), and HBP hypointense nodules without APHE were included. The OS model included a tumor size of > 5 cm, thin-rim APHE, TIV, and tumor vascular involvement other than TIV. The risk scores of the models showed good discriminatory performance in the external validation set (C-index, 0.62-0.76). The scoring system categorized the patients into three risk groups: favorable, intermediate, and poor, each with a distinct survival outcome (all log-rank p < 0.05). Conclusion: Risk scores based on rim arterial enhancement pattern, tumor size, HBP findings, and radiologic vascular invasion status may help predict postoperative RFS and OS in patients with targetoid primary liver malignancies.

T1 Map-Based Radiomics for Prediction of Left Ventricular Reverse Remodeling in Patients With Nonischemic Dilated Cardiomyopathy

  • Suyon Chang;Kyunghwa Han;Yonghan Kwon;Lina Kim;Seunghyun Hwang;Hwiyoung Kim;Byoung Wook Choi
    • Korean Journal of Radiology
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    • v.24 no.5
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    • pp.395-405
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    • 2023
  • Objective: This study aimed to develop and validate models using radiomics features on a native T1 map from cardiac magnetic resonance (CMR) to predict left ventricular reverse remodeling (LVRR) in patients with nonischemic dilated cardiomyopathy (NIDCM). Materials and Methods: Data from 274 patients with NIDCM who underwent CMR imaging with T1 mapping at Severance Hospital between April 2012 and December 2018 were retrospectively reviewed. Radiomic features were extracted from the native T1 maps. LVRR was determined using echocardiography performed ≥ 180 days after the CMR. The radiomics score was generated using the least absolute shrinkage and selection operator logistic regression models. Clinical, clinical + late gadolinium enhancement (LGE), clinical + radiomics, and clinical + LGE + radiomics models were built using a logistic regression method to predict LVRR. For internal validation of the result, bootstrap validation with 1000 resampling iterations was performed, and the optimism-corrected area under the receiver operating characteristic curve (AUC) with 95% confidence interval (CI) was computed. Model performance was compared using AUC with the DeLong test and bootstrap. Results: Among 274 patients, 123 (44.9%) were classified as LVRR-positive and 151 (55.1%) as LVRR-negative. The optimism-corrected AUC of the radiomics model in internal validation with bootstrapping was 0.753 (95% CI, 0.698-0.813). The clinical + radiomics model revealed a higher optimism-corrected AUC than that of the clinical + LGE model (0.794 vs. 0.716; difference, 0.078 [99% CI, 0.003-0.151]). The clinical + LGE + radiomics model significantly improved the prediction of LVRR compared with the clinical + LGE model (optimism-corrected AUC of 0.811 vs. 0.716; difference, 0.095 [99% CI, 0.022-0.139]). Conclusion: The radiomic characteristics extracted from a non-enhanced T1 map may improve the prediction of LVRR and offer added value over traditional LGE in patients with NIDCM. Additional external validation research is required.

Preparation of Vinyl Waste-derived Separator and Enhancement of Electrochemical Performance using Electrospinning and Plasma Treatment (전기방사와 산소 플라즈마 처리를 활용한 폐비닐 기반의 분리막 합성 및 전기화학적 성능 향상 연구)

  • Chan-Gyo Kim;Yoon-Ho Ra;Suk Jekal;Chang-Min Yoon
    • Journal of the Korea Organic Resources Recycling Association
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    • v.32 no.1
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    • pp.31-38
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    • 2024
  • In this study, vinyl waste, which is the cause of environmental pollution, is recycled via an electrospinning method and applied as a separator that can be employed for energy storage devices. In detail, vinyl wastes are dissolved in a solution containing p-xylene and cyclohexanone, followed by electrospinning to obtain a vinyl waste-derived separator(VWS), and then the hydrophilic functional groups on the surface of VWS are introduced using a plasma treatment to improve wettability. Scanning electron microscopy analysis have verified that the shape and thickness of as-spun VWS vary depending on the concentration of vinyl waste. The surface hydrophility of VWS is modified by plasma treatment with applied powers ranging from 80 to 120W. The lowest contact angle is observed when the 100W power is applied to VWS(VWS-100W). In electrochemical analysis, the VWS-100W-based supercapacitor device shows the highest specific capacitance of 57.9 F g-1. This is ascribed to the high porosity achieved by electrospinning as well as the introduction of hydrophilic functional groups by the oxygen plasma treatment. In conclusion, vinyl waste is successfully recycled into separators for energy storage devices, suggesting a new way to reduce environmental pollution.

Preoperative Prediction for Early Recurrence Can Be as Accurate as Postoperative Assessment in Single Hepatocellular Carcinoma Patients

  • Dong Ik Cha;Kyung Mi Jang;Seong Hyun Kim;Young Kon Kim;Honsoul Kim;Soo Hyun Ahn
    • Korean Journal of Radiology
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    • v.21 no.4
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    • pp.402-412
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    • 2020
  • Objective: To evaluate the performance of predicting early recurrence using preoperative factors only in comparison with using both pre-/postoperative factors. Materials and Methods: We retrospectively reviewed 549 patients who had undergone curative resection for single hepatcellular carcinoma (HCC) within Milan criteria. Multivariable analysis was performed to identify pre-/postoperative high-risk factors of early recurrence after hepatic resection for HCC. Two prediction models for early HCC recurrence determined by stepwise variable selection methods based on Akaike information criterion were built, either based on preoperative factors alone or both pre-/postoperative factors. Area under the curve (AUC) for each receiver operating characteristic curve of the two models was calculated, and the two curves were compared for non-inferiority testing. The predictive models of early HCC recurrence were internally validated by bootstrap resampling method. Results: Multivariable analysis on preoperative factors alone identified aspartate aminotransferase/platelet ratio index (OR, 1.632; 95% CI, 1.056-2.522; p = 0.027), tumor size (OR, 1.025; 95% CI, 0.002-1.049; p = 0.031), arterial rim enhancement of the tumor (OR, 2.350; 95% CI, 1.297-4.260; p = 0.005), and presence of nonhypervascular hepatobiliary hypointense nodules (OR, 1.983; 95% CI, 1.049-3.750; p = 0.035) on gadoxetic acid-enhanced magnetic resonance imaging as significant factors. After adding postoperative histopathologic factors, presence of microvascular invasion (OR, 1.868; 95% CI, 1.155-3.022; p = 0.011) became an additional significant factor, while tumor size became insignificant (p = 0.119). Comparison of the AUCs of the two models showed that the prediction model built on preoperative factors alone was not inferior to that including both pre-/postoperative factors {AUC for preoperative factors only, 0.673 (95% confidence interval [CI], 0.623-0.723) vs. AUC after adding postoperative factors, 0.691 (95% CI, 0.639-0.744); p = 0.0013}. Bootstrap resampling method showed that both the models were valid. Conclusion: Risk stratification solely based on preoperative imaging and laboratory factors was not inferior to that based on postoperative histopathologic risk factors in predicting early recurrence after curative resection in within Milan criteria single HCC patients.

NORMOBARIC OXYGEN($O_2$) ADMINISTRATION EFFECT ON ATTENTION AND MEMORY FUNCTION IN TEENAGE ADOLESCENTS (10대 청소년의 주의력과 기억능력에 미치는 정상기압 산소흡입 효과)

  • Kim, Byung-Hyo;Kim, Young-Mi;Cho, Soo-Churl;Kim, Boong-Nyun
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.13 no.1
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    • pp.76-84
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    • 2002
  • Objectives:This study was conducted to investigate the effect of oxygen on attention and memory functions in healthy adolescents. Methods:The participant subjects were recruited from local advertisement. All subjects are students attending ordinary middle and high school. Their degree of achievement was average or below average. Before the study, its nature and purpose were fully explained to the patients and their parents, and a written informed consent was obtained from each child's parent and a written assent from each child for entire the procedure. The Ethics Committee and Clinical Research Committee of Gyeongsang National University Hospital approved the protocol. For baseline assessment, all subjects received tests for attention and memory. All tests were conducted by a certified psychologist. Stroop test, continuous performance test and trail making test A and B were used for evaluation of attention. As memory tests, we used memory assessment scale(MAS), standardized memory assessment tools. Ten to fourteen days after initial assessments, same tests was applied to the same subjects after prior 5 minute oxygen inhalation. Results:1) Attention test:Improved performances in trail making part B, and stroop test were found in normobaric oxygen inhalation group compared to air inhalation group. Improved reaction time in those tests seemed to reflect the enhanced executive prefrontal activity. 2) Memory test:More words and digits memorization were found in short-term memory subscale score in MAS in oxygen inhalation group compared to air inhalation group. This finding suggested the improved working memory function after oxygen inhalation. Conclusion:Though interpreted cautiously, these results suggested that normobaric oxygen inhalation could enhance executive function and working memory of prefrontal lobe. Further study, however, should be performed to investigate the mechanism of effects of oxygen on cognitive enhancement.

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Enhancement of Fermentative Hydrogen Production by Gas Sparging (기체 sparging에 의한 수소 발효의 효율 향상)

  • Kim, Dong-Hoon;Han, Sun-Kee;Kim, Sang-Hyoun;Bae, Byung-Uk;Shin, Hang-Sik
    • Journal of the Korea Organic Resources Recycling Association
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    • v.12 no.1
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    • pp.49-57
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    • 2004
  • The effect of gas sparging on continuous fermentative $H_2$ production was investigated using external gases ($N_2$, $CO_2$) with various flow rates (100, 200, 300, 400 ml/min). Gas sparging showed a higher $H_2$ yield than no sparging, indicating that the decrease of $H_2$ partial pressure by gas sparging had a good effect on $H_2$ fermentation. Especially, $CO_2$ sparging was more effective in the reactor performance than $N_2$ sparging. The composition of butyrate, the main metabolic product of $H_2$ fermentation by Clostridium sp., was much higher in $CO_2$ sparging. $H_2$ production increased with increasing flow rate only in $CO_2$ sparging. The best performance was obtained by $CO_2$ sparging at 300 ml/min, resulting in the highest $H_2$ yield of 1.65 mol $H_2/mol$ hexoseconsumed and the maximum $H_2$ production of 6.77 L $H_2/g$ VSS/day. Compared to $N_2$ sparging, there could be another beneficial effect in $CO_2$ sparging apart from lowering down the $H_2$ partial pressure. High partial pressure of $CO_2$ had little effect on $H_2$ producing bacteria but inhibitory effect on other microorganisms like lactic acid bacteria and acetogens which were competitive with $H_2$ producing bacteria.

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Olympic Advertisers Win Gold, Experience Stock Price Gains During and After the Games (오운선수작위엄고대언인영득금패(奥运选手作为广告代言人赢得金牌), 비새중화비새후적고표개격상양(比赛中和比赛后的股票价格上扬))

  • Tomovick, Chuck;Yelkur, Rama
    • Journal of Global Scholars of Marketing Science
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    • v.20 no.1
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    • pp.80-88
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    • 2010
  • There has been considerable research examining the relationship between stockholders equity and various marketing strategies. These include studies linking stock price performance to advertising, customer service metrics, new product introductions, research and development, celebrity endorsers, brand perception, brand extensions, brand evaluation, company name changes, and sports sponsorships. Another facet of marketing investments which has received heightened scrutiny for its purported influence on stockholder equity is television advertisement embedded within specific sporting events such as the Super Bowl. Research indicates that firms which advertise in Super Bowls experience stock price gains. Given this reported relationship between advertising investment and increased shareholder value, for both general and special events, it is surprising that relatively little research attention has been paid to investigating the relationship between advertising in the Olympic Games and its subsequent impact on stockholder equity. While attention has been directed at examining the effectiveness of sponsoring the Olympic Games, much less focus has been placed on the financial soundness of advertising during the telecasts of these Games. Notable exceptions to this include Peters (2008), Pfanner (2008), Saini (2008), and Keller Fay Group (2009). This paper presents a study of Olympic advertisers who ran TV ads on NBC in the American telecasts of the 2000, 2004, and 2008 Summer Olympic Games. Five hypothesis were tested: H1: The stock prices of firms which advertised on American telecasts of the 2008, 2004 and 2000 Olympics (referred to as O-Stocks), will outperform the S&P 500 during this same period of time (i.e., the Monday before the Games through to the Friday after the Games). H2: O-Stocks will outperform the S&P 500 during the medium term, that is, for the period of the Monday before the Games through to the end of each Olympic calendar year (December 31st of 2000, 2004, and 2008 respectively). H3: O-Stocks will outperform the S&P 500 in the longer term, that is, for the period of the Monday before the Games through to the midpoint of the following years (June 30th of 2001, 2005, and 2009 respectively). H4: There will be no difference in the performance of these O-Stocks vs. the S&P 500 in the Non-Olympic time control periods (i.e. three months earlier for each of the Olympic years). H5: The annual revenue of firms which advertised on American telecasts of the 2008, 2004 and 2000 Olympics will be higher for those years than the revenue for those same firms in the years preceding those three Olympics respectively. In this study, we recorded stock prices of those companies that advertised during the Olympics for the last three Summer Olympic Games (i.e. Beijing in 2008, Athens in 2004, and Sydney in 2000). We identified these advertisers using Google searches as well as with the help of the television network (i.e., NBC) that hosted the Games. NBC held the American broadcast rights to all three Olympic Games studied. We used Internet sources to verify the parent companies of the brands that were advertised each year. Stock prices of these parent companies were found using Yahoo! Finance. Only companies that were publicly held and traded were used in the study. We identified changes in Olympic advertisers' stock prices over the four-week period that included the Monday before through the Friday after the Games. In total, there were 117 advertisers of the Games on telecasts which were broadcast in the U.S. for 2008, 2004, and 2000 Olympics. Figure 1 provides a breakdown of those advertisers, by industry sector. Results indicate the stock of the firms that advertised (O-Stocks) out-performed the S&P 500 during the period of interest and under-performed the S&P 500 during the earlier control periods. These same O-Stocks also outperformed the S&P 500 from the start of these Games through to the end of each Olympic year, and for six months beyond that. Price pressure linkage, signaling theory, high involvement viewers, and corporate activation strategies are believed to contribute to these positive results. Implications for advertisers and researchers are discussed, as are study limitations and future research directions.

A research on priority of the role and function of industrial high school recognized by industrial education specialist (공업계열 고등학교 역할과 기능의 우선 순위에 관한 공업교육 전문가 인식)

  • Oh, Seung-gyun;Kim, JinSoo
    • 대한공업교육학회지
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    • v.33 no.2
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    • pp.97-119
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    • 2008
  • The purpose of this research is to clarify the elements of the function of the role of industrial high schools that its experts perceived. The content of this research is verify the function element required for the performance of the role of specialized education through content validity ratio(CVR). This research adopted the method of literature research and Delphi method, which is to collect and come to an agreement of the opinions of the 26 research panels. The first round is constructed by the semi-constructed questionnaire for the analysis of the opinions of the panels by inductive method. The second round is to categorize the result of the first one into 7 domains, and asked each category by Likert's 5 scale checklists, and statistically analyzed mean, medium, standard deviation, and quartile. The third round is to statistically analyze Mean, standard deviation, medium, and validity ratio(CVR) to reassure the opinions of the panels on the basis of the result of the first one. The categorized contents of the function required for the performance of the specialized education in this research is 'in-service visit and in-service training', 'licence acquiring education', 'employment counseling and job employment information', 'custom-made education connected with industry', 'career education' and 'enhancement of basic career competency'. The panels are divided into professors, teachers, professionals, and policy administrators, and they verified the validity rate of the function role and priority of emphasis. The result showed that the tendency of the education is converting from physical function-centered education to education of emotional attitude and competence of thought.