• Journal of Food Hygiene and Safety
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• v.38 no.6
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• pp.420-429
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• 2023

GC-MS/MS using liquid-liquid extraction (LLE) and C18 cartridges was used to identify and quantify levels of chlorpyrifos, chlorpyrifos-methyl, cypermethrin, deltamethrin and permethrin in bulk raw milk. A calibration curve spanning 10 ng/mL to 200 ng/mL was obtained with a satisfactory correlation coefficient of 0.99. The limits of detection (LOD) and limits of quantitation (LOQ) for chlorpyrifos, chlorpyrifos-methyl, cypermethrin, deltamethrin, and permethrin in the matrix ranged from 0.06 to 1.81 ng/mL and 0.19 to 6.04 ng/mL, respectively. The recoveries of 5 pesticides from spiked samples at 37.5-125 ng/mL ranged from 86.1 to 102.1%. The measurement of uncertainty of the GC-MS/MS method for these five pesticides was developed based on the analytical process and quantification. An analysis method that is easier and faster than the method specified in the Korean food standards codes for analyzing these five pesticides in raw material milk was developed. Moreover, the analytical method for chlorpyrifos, chlorpyrifos-methyl, cypermethrin, deltamethrin, and permethrin in bulk raw milk by GC-MS/MS was established.

• Korean Journal of Remote Sensing
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• v.39 no.5_1
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• pp.577-587
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• 2023

The utilization of crowdsourced spatial data has been actively researched; however, issues stemming from the uncertainty of data quality have been raised. In particular, when low-quality data is mixed into drone imagery datasets, it can degrade the quality of spatial information output. In order to address these problems, the study presents a methodology for automatically validating the geometric quality of crowdsourced imagery. Key quality factors such as spatial resolution, resolution variation, matching point reprojection error, and bundle adjustment results are utilized. To classify imagery suitable for spatial information generation, training and validation datasets are constructed, and machine learning is conducted using a radial basis function (RBF)-based support vector machine (SVM) model. The trained SVM model achieved a classification accuracy of 99.1%. To evaluate the effectiveness of the quality validation model, imagery sets before and after applying the model to drone imagery not used in training and validation are compared by generating orthoimages. The results confirm that the application of the quality validation model reduces various distortions that can be included in orthoimages and enhances object identifiability. The proposed quality validation methodology is expected to increase the utility of crowdsourced data in spatial information generation by automatically selecting high-quality data from the multitude of crowdsourced data with varying qualities.

• Journal of Venture Innovation
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• v.4 no.3
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• pp.69-87
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• 2021

This study was conducted focusing on the innovative behavior necessary for the long-term survival of an organization in a business environment in which uncertainty and complexity are increasing. To this end, the relationship between issue leadership and innovative behavior of organizational members was investigated from the perspective of Signaling theory, Path-Goal theory and Job Demands-Resources theory. In addition, the mediating role of learning agility and sub-components of learning agility was empirically analyzed. For empirical analysis, a survey was conducted with a total of 252 team leaders and team members working in multinational companies (142 in Korea, 110 in the US). The results of this study are as follows. Issue leadership was analyzed to have a positive (+) effect on the innovative behavior of employees. Learning agility was found to play a mediating role between issue leadership and innovative behavior. On the other hand, the mediating effect was tested for each of the sub-components of learning agility, such as feedback seeking, information seeking, reflecting, experimenting, agility. As a result, all five sub-components were found to play a mediating role between issue leadership and innovative behavior. In particular, it was analyzed that the mediating effect of agility was the largest. Next, information seeking appeared to be large. Although there are some studies that have identified the mediating role of learning agility between issue leadership and innovative behavior, this study is considered to have academic implication as there are few cases of subdivided study. At the practical level, it is expected to provide implications for where to focus more when trying to improve an organization's learning agility and innovation behavior

• Journal of Industrial Convergence
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• v.21 no.11
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• pp.85-95
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• 2023

The purpose of this study is to provide evidences throught scoping review of education intervention studies for post kidney transplantation management in the kidney transplant patients in Korea. Through the search engines RISS, KISS, DB pia and Pubmed, 13 articles were selected by searching for theses and academic journals published prior to the search date of May 21, 2023. According to the study result, relevant studies were 13, and the education programs provided to kidney transplant patients were classified into 1) overall health management after transplantation, 2) self-efficacy promotion exercise program, 3) exercise therapy, 4) drug education, and 5) stress coping. Knowledge, implementation, self-efficacy, anxiety, uncertainty, stress, and quality of life were confirmed as effects of the intervention. Based on the results of this study, it is necessary to develop integrated educational materials and systematic self-management programs that can manage various health problems that may occur after kidney transplantation, and it is suggeste that research on educational interventions for kidney transplant patients in nursing.

• Tunnel and Underground Space
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• v.33 no.5
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• pp.312-338
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• 2023

The underground disposal facility for spent nuclear fuel demands a specialized design, distinct from conventional practices, to ensure long-term thermal, mechanical, and hydraulic integrity, preventing the release of radioactive isotopes from high-temperature spent nuclear fuel. SKB has established design criteria for such facilities and executed practical design implementations for Forsmark. Moreover, in response to subsurface uncertainty, SKB has proposed an empirical approach involving monitoring and adaptive design modifications, alongside stepwise development. SKB has further introduced a unique support system, categorizing ground types and behaviors and aligning them with corresponding support types to confirm safety through comparative analyses against existing systems. POSIVA has pursued a comparable approach, developing a support system for Onkalo while accounting for distinct geological characteristics compared to Forsmark. This demonstrates the potential for domestic implementation of spent nuclear fuel disposal facility designs and the establishment of a support system adapted to national attributes.

• Tunnel and Underground Space
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• v.33 no.5
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• pp.414-424
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• 2023

In this study, a total of 326 data on a variety of geometric parameters of pick cutters and the corresponding cuttable rock conditions were collected and built as a database. Statistical analysis of the database showed that there is a significant positive correlation between the parameters that define the geometry of a pick cutter, especially between the parameters related to the length of a pick cutter and the geometry of a tungsten carbide insert. The diameter of a pick cutter shaft was also strongly correlated with the geometry of the inserts. On the other hand, it was difficult to find a clear correlation between the parameters for the rock conditions defined by the four conditions and the geometric parameters of pick cutters, which may be due to the uncertainty of the rock mass and the fact that the application of a pick cutter is presented as a range rather than a numerical single value. However, the mean values of geometric parameters of pick cutters tend to increase as a rock mass becomes harder. However, the pick length parameters are found to decrease as a rock mass becomes harder, which may be a way to reduce the moments that can occur when using long pick cutters in a hard rock condition.

• Journal of The Korean Astronomical Society
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• v.56 no.2
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• pp.231-252
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• 2023

We present the analysis results of the simultaneous multifrequency observations of the blazar 4C +28.07. The observations were conducted by the Interferometric Monitoring of Gamma-ray Bright Active Galactic Nuclei (iMOGABA) program, which is a key science program of the Korean Very Long Baseline Interferometry (VLBI) Network (KVN). Observations of the iMOGABA program for 4C +28.07 were conducted from 16 January 2013 (MJD 56308) to 13 March 2020 (MJD 58921). We also used γ-ray data from the Fermi Large Array Telescope (Fermi-LAT) Light Curve Repository, covering the energy range from 100 MeV to 100 GeV. We divided the iMOGABA data and the Fermi-LAT data into five periods from 0 to 4, according to the prosody of the 22 GHz data and the presence or absence of the data. In order to investigate the characteristics of each period, the light curves were plotted and compared. However, a peak that formed a hill was observed earlier than the period of a strong γ-ray flare at 43-86 GHz in period 3 (MJD 57400-58100). Therefore, we assumed that the minimum total CLEANed flux density for each frequency was quiescent flux (S_q) in which the core of 4C +28.07 emitted the minimum, with the variable flux (S_var) obtained by subtracting S_q from the values of the total CLEANed flux density. We then compared the variability of the spectral indices (α) between adjacent frequencies through a spectral analysis. Most notably, α_22-43 showed optically thick spectra in the absence of a strong γ-ray flare, and when the flare appeared, α_22-43 became optically thinner. In order to find out the characteristics of the magnetic field in the variable region, the magnetic field strength in the synchrotron self-absorption (B_SSA) and the equipartition magnetic field strength (B_eq) were obtained. We found that B_SSA is largely consistent with B_eq within the uncertainty, implying that the SSA region in the source is not significantly deviated from the equipartition condition in the γ-ray quiescent periods.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.17 no.6
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• pp.1-12
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• 2022

This paper put the goal on boosting up early startup investment by delivering and positioning SAFE as the main early startup investment type in Korea. In particular, this paper proves the better fitting of SAFE as to the early stage of venture investment than these of Convertible Note. This paper as referring the previous studies of SAFE as the major keystone issues determining active SAFE applying (legal positioning issue, tax treatment issue, failure of inducing the following investment with uncertainty over maturity) proposes boosting up policy of Korean SAFE. First, as to accounting treatment of SAFE, it suggests SAFE to recognize legally as "the capital" on the Korean Venture Investment Act of introducing SAFE actively as venture investment type. Second, as to tax treatment issue, it proposes on amending venture indication rule as the best alternative of resolving tax issue by accepting SAFE as the investment meeting to venture investment requirement. Third, as benchmarking foreign cases, it delivers the method of modifying foreign SAFE Contract Format by adding up more clauses about safety vehicles against the failure of the following investment and fixing maturity date and event. Ultimately, all resolutions of this paper fall on highlighting the role of Korean Venture Investment Act and Ministry of SMEs and Startups.

• Journal of Korea Water Resources Association
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• v.57 no.1
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• pp.45-58
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• 2024

Drought risk is expected to increase as the frequency, intensity, and duration of droughts increase due to climate change. Drought risk is related to not only hydro-meteorological factors, but also water supply and demand. Recently, along with climate change, socioeconomic factors have also been recognized to increase drought risk. Therefore, it is necessary to outlook the drought risk considering various conditions for coping with future extreme droughts in a timely manner. In addition, considering various drought scenarios help reduce the uncertainty in future drought outlook. In this study, drought scenarios considering climate change scenarios, population, and water demand were created to outlook drought risk for 160 administrative districts in Korea, then new levels of drought risk were assigned based on the results of drought risk outlook to suggest drought management measures. The results showed that the drought risk will increase in the future in 2020, 2025, and 2030, compared to past. Especially the drought risk is likely twice as high in 2030 under the baseline and high scenarios. Applying the drought outlook results from this study to the new methodology for setting the risk levels shows that most regions are in Response (V) in 2020 and 2030 for baseline and high scenarios.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.19 no.1
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• pp.1-21
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• 2024

Recently, venture capital investment has been shrinking globally due to high interest rates and economic slowdown. Korea is no exception. Due to the downturn in the M&A and public markets, increasing economic uncertainty, and the aftermath of corporate bankruptcies, venture capitalists are facing many difficulties in raising funds. In the changed economic environment, the investment decision factors of venture capitalists have also changed. However, studies on VCs' investment decisions have focused on the general economic environment. This study examines how VCs' investment decision-making factors change during economic recessions and booms. To this end, we interviewed active investors who have experienced both economic recessions and booms to compare how VCs' investment decision factors change: 1) personal characteristics of founders, 2) experience of founders, 3) product/service, 4) market, 5) financial situation, 6) contract terms and 7) venture capital co-investment. The results showed that founder's personal characteristics, experience, and product/service were more important during the economic recession. Market is slightly more important during economic booms. The importance of financial situation and investment conditions increased sharply during the recession compared to the boom. Finally, venture capital co-investment did not differ significantly between recessions and booms. By understanding the investment decision-making factors of venture capitalists in the recent difficult venture investment environment, this study aims to help startups raise funds and survive in a difficult market.