• Title/Summary/Keyword: supply

Search Result 19,940, Processing Time 0.048 seconds

Factors that Influence Physician Salary Payment through Analyzing on Internet Invitation Webpage in Korea (초빙광고 자료를 활용한 봉직 의사의 급여수준과 관련요인)

  • Kang, Hyun Goo;Lee, Ji Hyung;Jung, Da-Doo;Lee, Moo-Sik
    • Journal of agricultural medicine and community health
    • /
    • v.46 no.1
    • /
    • pp.12-22
    • /
    • 2021
  • Backgrounds: Proper distribution and supply of physicians are factors that affect national health care systems. This study investigated the payment distribution levels and the determinants that influence the salary levels of hospital hired physicians. Methods: We analyzed 4,014 job advertisements posted on an internet invitation information site about physician recruitment from May 2016 to May 2019. We used univariate analysis to determine the relationship between average monthly salary and the other related variables. Multiple regression analysis was used to determine the predictors of physician salary level. Results: The average monthly salary for the service physician was 15.4 million won, highest for orthopedic surgeons with 22.24 million won, and lowest for diagnostic laboratory physician with 11.4 million won. The factors significantly associated with average monthly salary were; non-major specialty, housing provision, no severance pay, and incentives(p<0.05). Non-major specialty, incentives, and the regions were predictors of the average standardized monthly salary(p<0.05). Conclusion: Factors associated with average monthly salary as revealed by this study were; medical specialty, hospital regional location, housing provision, payment of retirement allowance, and payment of other incentives respectively. However, this study was a cross-sectional study, and further studies will be required.

The Influence of the Characteristics of Drainage Basin on Depositional Processes of the Alluvial Fan: An Example from the Cretaceous Duwon Formation in Goheung Area (유역분지 특성에 따른 충적선상지의 퇴적작용: 고흥군 백악기 두원층의 예)

  • Lee, Kyung Jin;Park, Seung-Ik;Lee, Hyojong;Gihm, Yong Sik
    • Economic and Environmental Geology
    • /
    • v.54 no.4
    • /
    • pp.441-456
    • /
    • 2021
  • The Cretaceous Duwon Formation was studied on the basis of sedimentologic analysis in order to unravel geologic conditions for the development of the streamflow-dominated alluvial fan under arid to semi-arid climatic conditions. The Duwon Formation unconformably overlies the Paleoproterozoic gneiss (basement). Based on the sedimentologic analysis, the Duwon Formation is interpreted to have been deposited in gravelly braided stream (FA-1) near the basement, laterally transitional to sandy braided stream (FA-2) and floodplain environments (FA-3) with distance (< 7 km) from the basement. Lateral changes in sedimentary facies and the well development of calcrete nodules in FA-3, together with radial paleocurrent directions measured in FA-1, are suggestive of the deposition of the Duwon Formation in streamflow-dominated alluvial fan under arid to semi-arid climatic conditions. Recent analysis of detrital zircon chronology suggests that sediments of the Duwon Formation were derived from the southwestern part of the Korean peninsula, including the western part of Yeongnam Massif and the southwestern part of Okcheon Belt. This implies the alluvial fan where the Duwon Formation accumulated had the large drainage basin. Because the large drainage basin can supply the significant amounts of water and temporarily store the sediments within the basin, watery floodwater carried sediments to the alluvial fan rather than the debris flows. Furthermore, the drainage basin largely composed of coarse-grained metamorphic and igneous rocks produced sand-grade sediments, preventing evolution of floodwater into debris flows. We suggest that combined effects of the large drainage basin and its coarse-grained metamorphic and igneous rocks provided favorable conditions for the development of streamflow-dominated alluvial fan, despite arid to semi-arid climatic conditions during sedimentation.

Analysis of Literatures Related to Crop Growth and Yield of Onion and Garlic Using Text-mining Approaches for Develop Productivity Prediction Models (양파·마늘 생산성 예측 모델 개발을 위한 텍스트마이닝 기법 활용 생육 및 수량 관련 문헌 분석)

  • Kim, Jin-Hee;Kim, Dae-Jun;Seo, Bo-Hun;Kim, Kwang Soo
    • Korean Journal of Agricultural and Forest Meteorology
    • /
    • v.23 no.4
    • /
    • pp.374-390
    • /
    • 2021
  • Growth and yield of field vegetable crops would be affected by climate conditions, which cause a relatively large fluctuation in crop production and consumer price over years. The yield prediction system for these crops would support decision-making on policies to manage supply and demands. The objectives of this study were to compile literatures related to onion and garlic and to perform data-mining analysis, which would shed lights on the development of crop models for these major field vegetable crops in Korea. The literatures on crop growth and yield were collected from the databases operated by Research Information Sharing Service, National Science & Technology Information Service and SCOPUS. The keywords were chosen to retrieve research outcomes related to crop growth and yield of onion and garlic. These literatures were analyzed using text mining approaches including word cloud and semantic networks. It was found that the number of publications was considerably less for the field vegetable crops compared with rice. Still, specific patterns between previous research outcomes were identified using the text mining methods. For example, climate change and remote sensing were major topics of interest for growth and yield of onion and garlic. The impact of temperature and irrigation on crop growth was also assessed in the previous studies. It was also found that yield of onion and garlic would be affected by both environment and crop management conditions including sowing time, variety, seed treatment method, irrigation interval, fertilization amount and fertilizer composition. For meteorological conditions, temperature, precipitation, solar radiation and humidity were found to be the major factors in the literatures. These indicate that crop models need to take into account both environmental and crop management practices for reliable prediction of crop yield.

Estimation of irrigation return flow from paddy fields on agricultural watersheds (농업유역의 논 관개 회귀수량 추정)

  • Kim, Ha-Young;Nam, Won-Ho;Mun, Young-Sik;An, Hyun-Uk;Kim, Jonggun;Shin, Yongchul;Do, Jong-Won;Lee, Kwang-Ya
    • Journal of Korea Water Resources Association
    • /
    • v.55 no.1
    • /
    • pp.1-10
    • /
    • 2022
  • Irrigation water supplied to the paddy field is consumed in the amount of evapotranspiration, underground infiltration, and natural and artificial drainage from the paddy field. Irrigation return flow is defined as the excess of irrigation water that is not consumed by evapotranspiration and crop, and which returns to an aquifer by infiltration or drainage. The research on estimating the return flow play an important part in water circulation management of agricultural watershed. However, the return flow rate calculations are needs because the result of calculating return flow is different depending on irrigation channel water loss, analysis methods, and local characteristics. In this study, the irrigation return flow rate of agricultural watershed was estimated using the monitoring and SWMM (Storm Water Management Model) modeling from 2017 to 2020 for the Heungeop reservoir located in Wonju, Gangwon-do. SWMM modeling was performed by weather data and observation data, water of supply and drainage were estimated as the result of SWMM model analysis. The applicability of the SWMM model was verified using RMSE and R-square values. The result of analysis from 2017 to 2020, the average annual quick return flow rate was 53.1%. Based on these results, the analysis of water circulation characteristics can perform, it can be provided as basic data for integrated water management.

Development of Electret to Improve Output and Stability of Triboelectric Nanogenerator (마찰대전 나노발전기의 출력 및 안정성 향상을 위한 일렉트렛 개발)

  • Kam, Dongik;Jang, Sunmin;Yun, Yeongcheol;Bae, Hongeun;Lee, Youngjin;Ra, Yoonsang;Cho, Sumin;Seo, Kyoung Duck;Cha, Kyoung Je;Choi, Dongwhi
    • Korean Chemical Engineering Research
    • /
    • v.60 no.1
    • /
    • pp.93-99
    • /
    • 2022
  • With the rapid development of ultra-small and wearable device technology, continuous electricity supply without spatiotemporal limitations for driving electronic devices is required. Accordingly, Triboelectric nanogenerator (TENG), which utilizes static electricity generated by the contact and separation of two different materials, is being used as a means of effectively harvesting various types of energy dispersed without complex processes and designs due to its simple principle. However, to apply the TENG to real life, it is necessary to increase the electrical output. In addition, stable generation of electrical output, as well as increase in electrical output, is a task to be solved for the commercialization of TENG. In this study, we proposed a method to not only improve the output of TENG but also to stably represent the improved output. This was solved by using the contact layer, which is one of the components of TENG, as an electret for improved output and stability. The utilized electret was manufactured by sequentially performing corona charging-thermal annealing-corona charging on the Fluorinated ethylene propylene (FEP) film. Electric charges artificially injected due to corona charging enter a deep trap through the thermal annealing, so an electret that minimizes charge escape was fabricated and used in TENG. The output performance of the manufactured electret was verified by measuring the voltage output of the TENG in vertical contact separation mode, and the electret treated to the corona charging showed an output voltage 12 times higher than that of the pristine FEP film. The time and humidity stability of the electret was confirmed by measuring the output voltage of the TENG after exposing the electret to a general external environment and extreme humidity environment. In addition, it was shown that it can be applied to real-life by operating the LED by applying an electret to the clap-TENG with the motif of clap.

Fabrication of Portable Self-Powered Wireless Data Transmitting and Receiving System for User Environment Monitoring (사용자 환경 모니터링을 위한 소형 자가발전 무선 데이터 송수신 시스템 개발)

  • Jang, Sunmin;Cho, Sumin;Joung, Yoonsu;Kim, Jaehyoung;Kim, Hyeonsu;Jang, Dayeon;Ra, Yoonsang;Lee, Donghan;La, Moonwoo;Choi, Dongwhi
    • Korean Chemical Engineering Research
    • /
    • v.60 no.2
    • /
    • pp.249-254
    • /
    • 2022
  • With the rapid advance of the semiconductor and Information and communication technologies, remote environment monitoring technology, which can detect and analyze surrounding environmental conditions with various types of sensors and wireless communication technologies, is also drawing attention. However, since the conventional remote environmental monitoring systems require external power supplies, it causes time and space limitations on comfortable usage. In this study, we proposed the concept of the self-powered remote environmental monitoring system by supplying the power with the levitation-electromagnetic generator (L-EMG), which is rationally designed to effectively harvest biomechanical energy in consideration of the mechanical characteristics of biomechanical energy. In this regard, the proposed L-EMG is designed to effectively respond to the external vibration with the movable center magnet considering the mechanical characteristics of the biomechanical energy, such as relatively low-frequency and high amplitude of vibration. Hence the L-EMG based on the fragile force equilibrium can generate high-quality electrical energy to supply power. Additionally, the environmental detective sensor and wireless transmission module are composed of the micro control unit (MCU) to minimize the required power for electronic device operation by applying the sleep mode, resulting in the extension of operation time. Finally, in order to maximize user convenience, a mobile phone application was built to enable easy monitoring of the surrounding environment. Thus, the proposed concept not only verifies the possibility of establishing the self-powered remote environmental monitoring system using biomechanical energy but further suggests a design guideline.

Effect of Strategic Orientation on Information Technology Competency and Corporate Performance in Small and Medium-Sized Enterprises(SMEs) (중소기업의 전략적 지향성이 정보기술역량과 기업성과에 미치는 영향)

  • Yang, Hee-Jong;Jang, Gil-Sang
    • The Journal of the Convergence on Culture Technology
    • /
    • v.7 no.4
    • /
    • pp.693-704
    • /
    • 2021
  • This study empirically verified the effect of strategic orientation on information technology(IT) competency and corporate performance for organizational members engaged in small and medium-sized enterprises (SMEs). In the research model proposed in this study, strategic orientation affects corporate performance, and IT competency is used as a mediating variable in this process. For this study, a survey was conducted on organizational members working in small and medium-sized manufacturers located in Ulsan Metropolitan City. A total of 320 questionnaires were distributed, and 277 copies were used in this study. The collected data were statistically analyzed using SPSS 24.0. The research results are as follows: First, customer orientation, market orientation, and technology orientation of strategic orientation were found to have a positive (+) effect on both information technology knowledge and information technology operation of IT competency. And it was found that both customer orientation and technology orientation of strategic orientation only affects the information technology infrastructure of IT competency. Second, it was found that customer orientation and technology orientation of strategic orientation had a positive (+) effect on corporate performance, but market orientation had no effect on corporate performance. Third, it was found that information technology knowledge, information technology operation, and information technology infrastructure of IT competency had a positive (+) effect on corporate performance. Fourth, as a result of examining the mediating effect of information technology competency between strategic orientation and corporate performance, information technology knowledge, information technology operation, and information technology infrastructure of IT capability were found to have a partial mediating effect between customer orientation and technology orientation of strategic orientation and corporate performance. These research results suggest that in today's fourth industrial revolution era, customer-oriented and technology-oriented management strategies should be established to improve the competitive advantage and performance of small and medium-sized enterprises(SMEs) in the supply chain with large enterprises, and at the same time information technology capabilities such as information technology knowledge, information technology operation, and information technology infrastructure should be strengthened.

The prediction of the stock price movement after IPO using machine learning and text analysis based on TF-IDF (증권신고서의 TF-IDF 텍스트 분석과 기계학습을 이용한 공모주의 상장 이후 주가 등락 예측)

  • Yang, Suyeon;Lee, Chaerok;Won, Jonggwan;Hong, Taeho
    • Journal of Intelligence and Information Systems
    • /
    • v.28 no.2
    • /
    • pp.237-262
    • /
    • 2022
  • There has been a growing interest in IPOs (Initial Public Offerings) due to the profitable returns that IPO stocks can offer to investors. However, IPOs can be speculative investments that may involve substantial risk as well because shares tend to be volatile, and the supply of IPO shares is often highly limited. Therefore, it is crucially important that IPO investors are well informed of the issuing firms and the market before deciding whether to invest or not. Unlike institutional investors, individual investors are at a disadvantage since there are few opportunities for individuals to obtain information on the IPOs. In this regard, the purpose of this study is to provide individual investors with the information they may consider when making an IPO investment decision. This study presents a model that uses machine learning and text analysis to predict whether an IPO stock price would move up or down after the first 5 trading days. Our sample includes 691 Korean IPOs from June 2009 to December 2020. The input variables for the prediction are three tone variables created from IPO prospectuses and quantitative variables that are either firm-specific, issue-specific, or market-specific. The three prospectus tone variables indicate the percentage of positive, neutral, and negative sentences in a prospectus, respectively. We considered only the sentences in the Risk Factors section of a prospectus for the tone analysis in this study. All sentences were classified into 'positive', 'neutral', and 'negative' via text analysis using TF-IDF (Term Frequency - Inverse Document Frequency). Measuring the tone of each sentence was conducted by machine learning instead of a lexicon-based approach due to the lack of sentiment dictionaries suitable for Korean text analysis in the context of finance. For this reason, the training set was created by randomly selecting 10% of the sentences from each prospectus, and the sentence classification task on the training set was performed after reading each sentence in person. Then, based on the training set, a Support Vector Machine model was utilized to predict the tone of sentences in the test set. Finally, the machine learning model calculated the percentages of positive, neutral, and negative sentences in each prospectus. To predict the price movement of an IPO stock, four different machine learning techniques were applied: Logistic Regression, Random Forest, Support Vector Machine, and Artificial Neural Network. According to the results, models that use quantitative variables using technical analysis and prospectus tone variables together show higher accuracy than models that use only quantitative variables. More specifically, the prediction accuracy was improved by 1.45% points in the Random Forest model, 4.34% points in the Artificial Neural Network model, and 5.07% points in the Support Vector Machine model. After testing the performance of these machine learning techniques, the Artificial Neural Network model using both quantitative variables and prospectus tone variables was the model with the highest prediction accuracy rate, which was 61.59%. The results indicate that the tone of a prospectus is a significant factor in predicting the price movement of an IPO stock. In addition, the McNemar test was used to verify the statistically significant difference between the models. The model using only quantitative variables and the model using both the quantitative variables and the prospectus tone variables were compared, and it was confirmed that the predictive performance improved significantly at a 1% significance level.

Experimental Study on Ignition and Explosion Hazard by Measuring the Amount of Non-volatile (NVR) and Explosion Limit of Biodiesel Mixture (바이오디젤 혼합물의 가열잔분측정과 폭발한계 측정을 통한 발화 및 폭발위험성에 대한 실험적인 연구)

  • Kim, Ju Suk;Koh, Jae-Sun
    • Journal of the Society of Disaster Information
    • /
    • v.18 no.1
    • /
    • pp.182-193
    • /
    • 2022
  • Purpose: By measuring and evaluating the risk of biodiesel through non-volatile residue (NVR) and flash point and explosion limit measurement at a specific temperature according to ASTM test standards, the risk of chemical fire causative substances is identified and a universal evaluation method By derivation and securing the risk-related data of the material, it can be used for the identification and analysis of the cause of the fire, and it can be applied to the risk assessment of other chemical substances Method: In order to measure the risk of biodiesel, it was measured using the non-volatile residue(NVR) measurement method, which measures how much flammable liquid is generated at a specific temperature. Heating was tested by applying KS M 5000: 2009 Test Method 4111. In addition, the flash point was measured using the method specified in ASTM E659-782005, and the energy supply method was measured using the constant temperature method. In addition, the explosion limit measurement was conducted in accordance with ASTM E 681-04 「Standard test method for concentration limits of flammability of chemicals(Vapors and gases)」 test standard. Result: As a result of checking the amount of combustible liquid by the non-volatile residue (NVR)measurement method, the non-volatile residue(NVR) of general diesel when left at 105±2℃ for 3 hours was about 30% (70% of volatile matter) and about 4% of biodiesel. In addition, similar results were obtained for the non-volatile residue(NVR)heating temperature of 150±2℃, 3 hours and 200±2℃ for 1 hour, and white smoke was generated at 200℃ or higher. In addition, similar values were obtained as a result of experimentally checking the explosion (combustion) limits of general diesel, general diesel containing 20% biodiesel, and 100% biodiesel. Therefore, it was confirmed that the flammability risk did not significantly affect the explosion risk. Conclusion: The results of this study suggested the risk judgment criteria for mixtures through experimental research on flammable mixtures for the purpose of securing the effectiveness, reliability, and reproducibility of the details of the criteria for determining dangerous substances in the existing Dangerous Materials Safety Management Act. It will be possible to provide reference data for the judgment criteria for flammable liquids that are regulated in the field. In addition, if the know-how for each test method is accumulated through this study, it is expected that it will be used as basic data in the research on risk assessment of dangerous substances and as a basis for research on the determination of dangerous substances.

Development of Smart Digital Agriculture Technology for Food Crop Production in Korea-The Path Forward Based on Expert Feedback (식량작물 생산에 대한 스마트디지털 농업기술의 발전 방향 - 전문가 설문조사 연구)

  • Song, Ki Eun;Jung, Jae Gyeong;Cho, Seungho;Kim, Jae Yoon;Shim, Sangin
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.67 no.1
    • /
    • pp.27-40
    • /
    • 2022
  • Building self-sustainable rural infrastructure and environment through smart digital agriculture technology innovation is one of the major goals of the Korean agricultural administration as a part of the nation's 4th industry revolution. To identify areas for improving and effectively investing in the acceleration of rural development, 207 experts in the areas of crop science and smart digital agriculture technology were interviewed for their opinions and suggestions on 22 questions designed to recognize fundamental agricultural issues to be addressed and solutions to advance technology innovation and rural development. Majority of the participants expected smart digital agriculture technologies to resolve major agricultural issues and help build a better rural environment. To overcome technology gaps and resolve issues more effectively, further investment in training new technology experts and building stronger agricultural technology infrastructure is urgent, and persistent and systematic support from agricultural administration appears to be the key for accelerating the process. While the leading global groups of both public and private sectors have advanced their technologies beyond the field application stage, most of the Korean technologies remain at the early pilot stage. Aging population and lack of labor in rural areas, unknown future climate change, and challenges in sustainable rural development are expected to be resolved by smart digital agriculture technologies. Technological innovations by research institutes should be promptly deployed in the crop production field, and farm training systemically organized by local technology centers can accelerate farming revolution. Standardization of equipment and data systems is another key to the success of digitalization of food crop production and food supply chains nationwide.