• Title/Summary/Keyword: 회수년

Search Result 897, Processing Time 0.025 seconds

Optimization Process Models of Gas Combined Cycle CHP Using Renewable Energy Hybrid System in Industrial Complex (산업단지 내 CHP Hybrid System 최적화 모델에 관한 연구)

  • Oh, Kwang Min;Kim, Lae Hyun
    • Journal of Energy Engineering
    • /
    • v.28 no.3
    • /
    • pp.65-79
    • /
    • 2019
  • The study attempted to estimate the optimal facility capacity by combining renewable energy sources that can be connected with gas CHP in industrial complexes. In particular, we reviewed industrial complexes subject to energy use plan from 2013 to 2016. Although the regional designation was excluded, Sejong industrial complex, which has a fuel usage of 38 thousand TOE annually and a high heat density of $92.6Gcal/km^2{\cdot}h$, was selected for research. And we analyzed the optimal operation model of CHP Hybrid System linking fuel cell and photovoltaic power generation using HOMER Pro, a renewable energy hybrid system economic analysis program. In addition, in order to improve the reliability of the research by analyzing not only the heat demand but also the heat demand patterns for the dominant sectors in the thermal energy, the main supply energy source of CHP, the economic benefits were added to compare the relative benefits. As a result, the total indirect heat demand of Sejong industrial complex under construction was 378,282 Gcal per year, of which paper industry accounted for 77.7%, which is 293,754 Gcal per year. For the entire industrial complex indirect heat demand, a single CHP has an optimal capacity of 30,000 kW. In this case, CHP shares 275,707 Gcal and 72.8% of heat production, while peak load boiler PLB shares 103,240 Gcal and 27.2%. In the CHP, fuel cell, and photovoltaic combinations, the optimum capacity is 30,000 kW, 5,000 kW, and 1,980 kW, respectively. At this time, CHP shared 275,940 Gcal, 72.8%, fuel cell 12,390 Gcal, 3.3%, and PLB 90,620 Gcal, 23.9%. The CHP capacity was not reduced because an uneconomical alternative was found that required excessive operation of the PLB for insufficient heat production resulting from the CHP capacity reduction. On the other hand, in terms of indirect heat demand for the paper industry, which is the dominant industry, the optimal capacity of CHP, fuel cell, and photovoltaic combination is 25,000 kW, 5,000 kW, and 2,000 kW. The heat production was analyzed to be CHP 225,053 Gcal, 76.5%, fuel cell 11,215 Gcal, 3.8%, PLB 58,012 Gcal, 19.7%. However, the economic analysis results of the current electricity market and gas market confirm that the return on investment is impossible. However, we confirmed that the CHP Hybrid System, which combines CHP, fuel cell, and solar power, can improve management conditions of about KRW 9.3 billion annually for a single CHP system.

The Present Situation and Challenges of the Russian Music Industry: Centered on the Digital Sound Sources (러시아 음악 산업 현황과 과제 - 디지털 음원을 중심으로 -)

  • Kwon, ki-bae;Kim, Se-il
    • Cross-Cultural Studies
    • /
    • v.50
    • /
    • pp.395-424
    • /
    • 2018
  • The purpose of this paper is to examine the current situation and background of the Russian consumer music market, where digital music sources are making great strides in the noted recent years. In addition, music storage technology, media and change are considered together in this report. Moreover, Russia is the 12th largest music market in the world. The Russian music industry is following the recent trend of the global music industry, where the digital music market is growing rapidly on many different levels. The explosive growth of the digital sound sources in Russia's music industry is attributed to the explosive increase in available consumer downloads, streaming sound source service, and the increase in the number of digital sound sources using mobile technologies due to the development of the Internet. In particular, the sales of the available and accessible streaming sound sources are expected to grow explosively by the year 2020, which is expected to account for more than 85% of total digital music sales. In other words, the spread of smartphones and the resulting changes in the lifestyle of the Russians have created these changes for the global consumer of music. In other words, the time has come for anyone to easily access music and listen to music without a separate audio or digital player. And the fact that the Russian government's strong policy on the eradication of illegal copying of music is becoming an effective deterrent, as is also the factor that led to the increase of the share of the digital sound source to increase sales in Russia. Today, the Russian music industry is leading this change through the age and process of simply adapting to the digital age. Music is the most important element of cultural assets, and it is the beneficial content, which drives the overall growth of the digital economy. In addition, if the following five improvements(First, strengthen the consciousness of the Russian people about copyright protection; Second, utilizing the Big Data Internet resources in the digital music industry; Third, to improve the monopoly situation of digital music distributors; Fourth, distribution of fair music revenues; and Fifth, revitalization of a re-investment in the current Russian music industry) are effective and productive, Russia's role and position in the world music market is likely to expand.

A Study on the Satisfaction and Improvement Plan of Fraud Prevention Education about Technical and Vocational Education and Training (직업훈련 부정 예방교육 만족도 조사와 개선방안 연구)

  • Jeong, Sun Jeong;Lee, Eun Hye;Lee, Moon Su
    • Journal of vocational education research
    • /
    • v.37 no.5
    • /
    • pp.25-53
    • /
    • 2018
  • The purpose of this study is to find out the improvement plan through the satisfaction survey of the trainees involved in vocational training fraud preventive education. In order to do this, we conducted a satisfaction survey(4,263 persons) of 5,939 people who participated in the prevention education conducted by group education or e-learning in 2017. Finally we collected 4,237 effective responses data. Descriptive statistics and the regression analysis were conducted. The finding of the study were as follows. First, the education service quality(4.42), satisfaction level(4.44), understanding level(4.44) and help level(4.45) were significantly higher than those of participants in the preventive education 4 and above. Second, e-learning participants' perceived level of education service quality, satisfaction, comprehension, and help was higher in all variables than collective education's. Third, all of the sub-factors of preventive education service quality influenced satisfaction, understanding, and help in collective education and e-learning, respectively. In the collective education, the contents of education had the greatest influence, and in e-learning, the data composition had the greatest influence. Fourth, desirable education contents were cases of fraud training(70.7%), disposition regulations(47.9%), NCS course operation instructions(32.8%) and training management best practices(32.4%). Additional requirements also included the establishment of an in-depth course, the provision of anti-fraud education content for trainees, and screen switching and system stability that can be focused on e-learning. Therefore, this study suggests that first, it is necessary to activate e-learning for prevention education more, reflecting satisfaction of e-learning is higher than that of collective education. Second, it is necessary to diversify the content of preventive education and to provide it more abundantly, because it has the biggest influence in common with the satisfaction, understanding and help level of the preventive education. Third, education content next, the factors that have a relatively big influence on satisfaction are shown as delivery method and education place in the collective education. Therefore, it is necessary to prepare education place considering the assignment of instructor and convenience. Fourth, constructing data next, the factor that have a relatively great influence on understanding and help are found to be operator support, and more active operator support activities are required in e-learning. Fifth, it is required to delivery prevention activity for trainees participating in vocational training. Sixth, it is necessary to analyze the educational need to construct the contents of preventive education more systematically.

Korean Start-up Ecosystem based on Comparison of Global Countries: Quantitative and Qualitative Research (글로벌 국가 비교를 통한 한국 기술기반 스타트업 생태계 진단: 정량 및 정성 연구)

  • Kong, Hyewon
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
    • /
    • v.14 no.1
    • /
    • pp.101-116
    • /
    • 2019
  • Technology-based start-up is important in that it encourages innovation, facilitates the development of new products and services, and contributes to job creation. Technology-based start-up activates entrepreneurship when appropriate support is provided within the ecosystem. Thus, understanding the technology-based start-up ecosystem is crucial. The purpose of this study is as follows. First, in Herrmann et al.'s(2015) study, we compare and analyze the ecosystem of each country by selecting representative regions such as Silicon Valley, Tel Aviv, London and Singapore which have the highest ranking in the start-up ecosystem. Second, we try to deeply understand the start-up ecosystem based on in-depth interviews with various stakeholders such as VC investors, start-ups, support organizations, and professors related to the Korean start-up ecosystem. Finally, based on the results of the study, we suggest development and activation of Korean technology-based start-up ecosystem. As a result, the Seoul start-up ecosystem showed a positive evaluation of government support compared to other advanced countries. In addition, it was confirmed that the ratio of tele-work and start-up company working experience of employees was higher than other countries. On the other hand, in Seoul, It was confirmed that overseas market performance, human resource diversity, attracting investment, hiring technological engineers, and the ratio of female entrepreneurs were lower than those of overseas advanced countries. In addition, according to the results of the interview analysis, Seoul was able to find that start-up ecosystems such as individual angel investors, accelerators, support institution, and media are developing thanks to the government's market-oriented policy support. However, in order for this development to continue, it is necessary to improve the continuous investment system, expansion of diversity, investment return system, and accessibility to the global market. A discussion on this issue is presented.

Development of Simultaneous Analytical Method for Streptomycin and Dihydrostreptomycin Detection in Agricultural Products Using LC-MS/MS (LC-MS/MS를 이용한 농산물 중 Streptomycin 및 Dihydrostreptomycin 동시시험법 개발)

  • Lee, Han Sol;Do, Jung-Ah;Park, Ji-Su;Park, Shin-Min;Cho, Sung Min;Shin, Hye-Sun;Jang, Dong Eun;Choi, Young-Nae;Jung, Yong-hyun;Lee, Kangbong
    • Journal of Food Hygiene and Safety
    • /
    • v.34 no.1
    • /
    • pp.13-21
    • /
    • 2019
  • A method was developed for the simultaneous detection of an antibiotic fungicide, streptomycin, and its metabolite (dihydrostreptomycin) in agricultural products using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The samples were extracted using methanol adjusted to pH 3 using formic acid, and purified with a HLB (Hydrophilic lipophilic balance) cartridge. The matrix-matched calibration curves were constructed using seven concentration levels, from 0.001 to 0.1 mg/kg, and linearity of five agricultural products (hulled rice, potato, soybean, mandarin, green pepper), with coefficients of determination $(R^2){\geq}0.9906$, for streptomycin and dihydrostreptomycin. The mean recoveries at three fortification levels (LOQ, $LOQ{\times}10$, $LOQ{\times}50$, n = 5) were from 72.0~116.5% and from 72.1~116.0%, and relative standard deviations were less than 12.3% and 12.5%, respectively. The limits of quantification (LOQ) were 0.01 mg/kg, which are satisfactory for quantification levels corresponding with the Positive List System. All optimized results satisfied the criteria ranges requested in the Codex guidelines and the Food Safety Evaluation Department guidelines. The present study could serve as a reference for the establishment of maximum residue limits and be used as basic data for detection of streptomycin and dihydrostreptomycin in food.

A Safety Survey on Pesticide Residues in Dried Agricultural Products (건조농산물의 잔류농약 안전성 조사)

  • Lee, Hyo-Kyung;Oh, Moon-Seog;Jeong, Jin-A;Kim, Ki-Yu;Lee, Seong-Bong;Kim, Han-Taek;Kang, Hyang-Ri;Son, Ji-Hee;Lee, Yun-Mi;Lee, Mi-Kyoung;Lee, Byoung-Hoon;Kim, Ji-Won;Park, Yong-Bae
    • Journal of Food Hygiene and Safety
    • /
    • v.34 no.4
    • /
    • pp.340-347
    • /
    • 2019
  • We performed a safety survey on residual pesticides in dried agricultural products. A total of 110 samples of dried agricultural products distributed in Gyeonggi-do were analyzed for 263 pesticides according to multi class pesiticide multiresidue method. Ten types of pesticides were detected in 10 samples. Chlorpyrifos was detected in Ricinus communis leaves, chlorpyrifos, hexaconazole, pyridalyl in Chwinamul (wild aster), diniconazole, isoprothiolane, lufenuron in radish leaves, hexaconazole in Cirsium setidens (Korean thistle), bifenthrin, and chlorothalonil, boscalid, and pyraclostrobin in pepper leaves. The detection rate of pesticides was 9.1%, and among these samples, one was detected over Maximum Residue Limits (MRLs). In the validation study, the values of limit of detection (LOD), limit of quantitation (LOQ), coefficient of determination ($R^2$) and recovery were in the range of 0.002~0.027 mg/kg, 0.006~0.083 mg/kg, 0.9964~1.0000 and 74.8~118.9%, respectively. The Positive List System (PLS) was newly introduced as part of the safety management of residual pesticide in agricultural products in Korea in 2019. With the application of the PLS, if the MRL is not established, 0.01 mg/kg limit is applied uniformly. In spite, these of strengthened residue limits, the MRLs of dried agricultural products are still insufficient. Therefore, this study could be utilized as basic data for the setting of proper MRLs.

Determination of Mycotoxins in Agricultural Products Used for Food and Medicine Using Liquid Chromatography Triple Quadrupole Mass Spectrometry and Their Risk Assessment (LC-MS/MS를 이용한 식·약 공용 농산물의 곰팡이독소 분석 및 위해평가)

  • Choi, Su-Jeong;Ko, Suk-Kyung;Park, Young-Ae;Jung, Sam-Ju;Choi, Eun-Jung;Kim, Hee-sun;Kim, Eun-Jung;Hwang, In-Sook;Shin, Gi-Young;Yu, In-Sil;Shin, Yong-Seung
    • Journal of Food Hygiene and Safety
    • /
    • v.36 no.1
    • /
    • pp.24-33
    • /
    • 2021
  • For this study, we surveyed concentrations of 8 mycotoxins (aflatoxin B1, B2, G1, G2, ochratoxin A, fumonisin B1, B2 and zearalenone) in agricultural products used for food and medicine by liquid chromatography-tandem mass spectrometry and conducted a risk assessment. Samples were collected at the Yangnyeong Market in Seoul, Korea, between January and November 2019. Mycotoxins were extracted from these samples by adding 0.1% formic acid in 50% acetonitrile and cleaned up by using an ISOLUTE Myco cartridge. The method was validated by assessing its matrix effects, linearity, limit of detection (LOD), limit of quantification (LOQ), recovery and precision using four representative matrices. Matrix-matched standard calibration was used for quantification and the calibration curves of all analytes showed good linearity (r2>0.9999). LODs and LOQs were in the range of 0.02-0.11 ㎍/kg and 0.06-0.26 ㎍/kg, respectively. Sample recoveries were from 81.2 to 118.7% and relative standard deviations lower than 8.90%. The method developed in this study was applied to analyze a total of 187 samples, and aflatoxin B1 was detected at the range of 1.18-7.29 ㎍/kg (below the maximum allowable limit set by the Ministry of Food and Drug Safety, MFDS), whereas aflatoxin B2, G1 and G2 were not detected. Mycotoxins that are not regulated presently in Korea were also detected: fumonisin (0.84-14.25 ㎍/kg), ochratoxin A (0.76-17.42 ㎍/kg), and zearalenone (1.73-15.96 ㎍/kg). Risk assessment was evaluated by using estimated daily intake (EDI) and specific guideline values. These results indicate that the overall exposure level of Koreans to mycotoxins due to the intake of agricultural products used for food and medicine is unlikely to be a major risk factor for their health.

Simultaneous determination of 11-nor-Δ9-carboxy-tetrahydrocannabinol and 11-nor-Δ9-carboxy-tetrahydrocannabinol-glucuronide in urine samples by LC-MS/MS and its application to forensic science (LC-MS/MS를 이용한 소변 중 11-nor-Δ9-carboxy-tetrahydrocannabinol 및 11-nor-Δ9-carboxy-tetrahydrocannabinol-glucuronide의 동시 분석 및 법과학적 적용)

  • Park, Meejung;Kim, Sineun
    • Analytical Science and Technology
    • /
    • v.34 no.6
    • /
    • pp.259-266
    • /
    • 2021
  • Cannabis (Marijuana) is one of the most widely used drugs in the world, and its distribution has been controlled in South Korea since 1976. Identification of 11-nor-Δ9-carboxy-tetrahydrocannabinol (THCCOOH) in urine can provide important proof of cannabis use, and it is considered scientific evidence in the forensic field. In this study, we describe a simultaneous quantitative method for identifying THCCOOH and THCCOOH-glucuronide in urine, using simple liquid-liquid extraction (LLE), and liquid chromatography-tandem mass spectrometry (LC-MS/MS). THCCOOH-D3 and THCCOOH-glucuronide-D3 were used as internal standards. Validation results of the matrix effect, as well as recovery, linearity, precision, accuracy, process efficiency, and stability were all satisfactory. No carryover, endogenous or exogenous interferences were observed. The limit of detection (LOD) of THCCOOH and THCCOOH-glucuronide were 0.3 and 0.2 ng/mL, respectively. The developed method was applied to 28 authentic human urine samples that tested positive in immunoassay screening and gas chromatography/mass spectrometry (GC/MS) tests. The ranges of concentrations of THCCOOH and THCCOOH-glucuronide in the samples were less than LOQ~266.90 ng/mL and 6.43~2133.03 ng/mL, respectively. The concentrations of THCCOOH-glucuronide were higher than those of THCCOOH in all samples. This method can be effectively and successfully applied for the confirmation of cannabinoid use in human urine samples in the forensic field.

The Knowledge Transfer Network and Performance of Chinese Subsidiary in Korean MNCs : Focusing on Roles of Absorptive Capacity and Entry Mode (한국 다국적기업의 중국 자회사의 지식이전, 네트워크와 경영성과에 관한 연구 - 흡수능력과 진입방식의 역할을 중심으로 -)

  • Yoon, Ki-Chang
    • Korea Trade Review
    • /
    • v.41 no.5
    • /
    • pp.325-351
    • /
    • 2016
  • This study empirically investigated the relationship among knowledge transfer, network(firm network and government network) and performance Korean MNCs' subsidiaries in terms of absorptive capacity and entry mode roles in China. For this, absorptive capacity was established as an independent variable, mediating variable, and moderating variable. And the entry mode was divided into single investment and joint venture and set to the moderating variable. Data for the analysis of actual proof was randomly selected from the companies which was established more than 3 years before KOTRA 'The overseas expansion Korean company directory (2014)'. Questionnaires to 138 Chinese subsidiaries of Korean MNCs were collected by FAX and E-mail. AMOS was utilized and collected data investigated the role of the absorption capacity and entry mode as the covariance structure analysis. The empirical analysis showed that absorption capacity has a direct influence on management performance as an independent variable with the network (firm network and government network). It only has a partial mediating role between enterprise networks and management performance, and no meaningful result was gained as its moderationg role bewteen the exogenous variable and management performance. And in terms of Korean companies' moderating role in entering China, they have a moderating role between government network, absorption capacity and management performance, but did not show a statistically significant result between knowledge transfer, enterprise network and management performance. Absorption capacity, as the variable affecting overseas subsidiary's management performance, should not be considered a mediating or moderating variable, but an independent variable. Since the joint venture is showing higher performance than single investment when going into the Chinese market, implication is provided for options in overseas expansion. But this research has the limitation in generalization because it is aiming at the subsidiaries of the Korean company investing in China. Therefore, it is more desirable in the future to conduct a study of the subsidiary of the Korean company entering several countries. It also has limitations in generalization, because the research was conducted using a limited number of variables, despite there are various factors affecting the management performance of Chinese subsidiaries.

  • PDF

Moderating effects of perceived behavioral control on the relationships among exhibition sales promotions and purchase intention (전시회 판매촉진 활동이 지각된 행동통제의 조절효과와 구매의도에 미치는 영향연구)

  • Kim, Hyun Su;Kim, Mi So;Kim, Chul Won
    • Korea Science and Art Forum
    • /
    • v.31
    • /
    • pp.105-118
    • /
    • 2017
  • The purpose of study is to examine the effectiveness of exhibition sales promotions and purchase intention for reasonable visitors. Perceived behavior control determining moderating effects on the relationship among their sales promotions and purchase intention is used as a predictive variable of unexpected impulsive purchases or negative purchase intention contrary to business intention. A total of 315 visitors who experienced the sales promotions of G-Star 2016 in Busan respond to the questionnaire and 259 forms are used to analyze the data. The main results of this study were as follows. First, except to value-added sales promotion, all of sales promotions positively impact on visitors' purchase intention. Second, as a result of analyzing the moderating effects of the perceived behavioral control consisting of control belief and perceived power on the relationships among the sales promotions and purchase intention, the control belief moderated the sales promotions such as price-off and education on purchase intention. In addition, the perceived power moderated the sales promotions such as escape and entertainment on purchase intention. In a nutshell, the degree of perceived behavior control makes critically impact on the effectiveness of exhibition sales promotions. Based on this results, it yields new insights into the way of developing various sales promotion strategies according to different features of visitors.