• Title/Summary/Keyword: control strategies

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Effect of Cold Storage on Quality of Geocoris pallidipennis and Micromus angulatus (저온저장이 포식성 천적인 참딱부리긴노린재와 갈고리뱀잠자리붙이의 품질에 미치는 영향)

  • Seo, Meeja;Kim, Jeong Hwan;Seo, Bo Yoon;Park, Bueyong;Lee, Sang Gu;Kim, Kwang Ho;Cho, Jum Rae
    • Korean journal of applied entomology
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    • v.58 no.2
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    • pp.151-157
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    • 2019
  • It was available to store both nymphs and adults of Geocoris pallidipennis at $5^{\circ}C$ for 3 weeks without negative effects on their survival, fecundity, and Bemisia tabaci predation. Fecundities of G. pallidipennis showed the tendency to be decreased with increasing cold storage duration, but up to 4 weeks, storage at $5^{\circ}C$ didn't affect their fecundity. When Micromus angulatus adults were stored at $5^{\circ}C$ with honey solution as preys, it was possible to store up to 140 days showing approximately 50% of cumulative survival, but over 2 week cold storage was not suitable for their fecundity. With the increase of cold storage duration, the aphid predation by M. angulatus decreased, but it could be possible to cold store until 5 weeks without any significant effect on their aphid predation. Thus, short term cold storage of G. pallidipennis and M. angulatus could be useful for inundative biological strategies.

The Effects of Game User's Social Capital and Information Privacy Concern on SNGReuse Intention and Recommendation Intention Through Flow (게임 이용자의 사회자본과 개인정보제공에 대한 우려가 플로우를 통해 SNG 재이용의도와 추천의도에 미치는 영향)

  • Lee, Ji-Hyeon;Kim, Han-Ku
    • Management & Information Systems Review
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    • v.37 no.4
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    • pp.21-39
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    • 2018
  • Today, Mobile Instant Message (MIM) has become a communication means which is commonly used by many people as the technology on smart phones has been enhanced. Among the services, KakaoGame creates much profits continuously by using its representative Kakao platform. However, even though the number of users of KakaoGame increases and the characteristics of the users are more diversified, there are few researches on the relationship between the characteristics of the SNG users and the continuous use of the game. Since the social capital that is formed by the SNG users with the acquaintances create the sense of belonging, its role is being emphasized under the environment of social network. In addition, game user's concerns about the information privacy may decrease the trust on a game APP, and it also caused to threaten about the game system. Therefore, this study was designed to examine the structural relationships among SNG users' social capital, concerns about the information privacy, flow, SNG reuse intention and recommendation intention. The results from this study are as follow. First of all, the participants' bridging social capital had a positive effect on the flow of an SNG, but the bonding social capital had a negative effect on the flow of an SNG. In addition, awareness of information privacy concern had a negative effects on the flow of an SNG, but control of information privacy concern had a positive effect on the flow of an SNG. Lastly, the flow of an SNG had a positive effect on the reuse intention and recommendation intention of an SNG. Also, reuse intention of an SNG had a positive effect on the recommendation intention. Based on the results from this study, academic and practical implications can be drawn. First, This study focused on KakaoTalk which has both of the closed and open characteristics of an SNS and it was found that the SNG user's social capital might be a factor influencing each user's behaviors through the user's flow experiences in SNG. Second, this study extends the scope of prior researches by empirically analysing the relationship between the concerns about the SNG user's information privacy and flow of an SNG. Finally, the results of this research can provide practical guidelines to develop effective marketing strategies considering them for SNG companies.

Development of A Material Flow Model for Predicting Nano-TiO2 Particles Removal Efficiency in a WWTP (하수처리장 내 나노 TiO2 입자 제거효율 예측을 위한 물질흐름모델 개발)

  • Ban, Min Jeong;Lee, Dong Hoon;Shin, Sangwook;Lee, Byung-Tae;Hwang, Yu Sik;Kim, Keugtae;Kang, Joo-Hyon
    • Journal of Wetlands Research
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    • v.24 no.4
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    • pp.345-353
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    • 2022
  • A wastewater treatment plant (WWTP) is a major gateway for the engineered nano-particles (ENPs) entering the water bodies. However existing studies have reported that many WWTPs exceed the No Observed Effective Concentration (NOEC) for ENPs in the effluent and thus they need to be designed or operated to more effectively control ENPs. Understanding and predicting ENPs behaviors in the unit and \the whole process of a WWTP should be the key first step to develop strategies for controlling ENPs using a WWTP. This study aims to provide a modeling tool for predicting behaviors and removal efficiencies of ENPs in a WWTP associated with process characteristics and major operating conditions. In the developed model, four unit processes for water treatment (primary clarifier, bioreactor, secondary clarifier, and tertiary treatment unit) were considered. Additionally the model simulates the sludge treatment system as a single process that integrates multiple unit processes including thickeners, digesters, and dewatering units. The simulated ENP was nano-sized TiO2, (nano-TiO2) assuming that its behavior in a WWTP is dominated by the attachment with suspendid solids (SS), while dissolution and transformation are insignificant. The attachment mechanism of nano-TiO2 to SS was incorporated into the model equations using the apparent solid-liquid partition coefficient (Kd) under the equilibrium assumption between solid and liquid phase, and a steady state condition of nano-TiO2 was assumed. Furthermore, an MS Excel-based user interface was developed to provide user-friendly environment for the nano-TiO2 removal efficiency calculations. Using the developed model, a preliminary simulation was conducted to examine how the solid retention time (SRT), a major operating variable affects the removal efficiency of nano-TiO2 particles in a WWTP.

Analysis of Spatial Correlation between Surface Temperature and Absorbed Solar Radiation Using Drone - Focusing on Cool Roof Performance - (드론을 활용한 지표온도와 흡수일사 간 공간적 상관관계 분석 - 쿨루프 효과 분석을 중심으로 -)

  • Cho, Young-Il;Yoon, Donghyeon;Lee, Moung-Jin
    • Korean Journal of Remote Sensing
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    • v.38 no.6_2
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    • pp.1607-1622
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    • 2022
  • The purpose of this study is to determine the actual performance of cool roof in preventing absorbed solar radiation. The spatial correlation between surface temperature and absorbed solar radiation is the method by which the performance of a cool roof can be understood and evaluated. The research area of this study is the vicinity of Jangyu Mugye-dong, Gimhae-si, Gyeongsangnam-do, where an actual cool roof is applied. FLIR Vue Pro R thermal infrared sensor, Micasense Red-Edge multi-spectral sensor and DJI H20T visible spectral sensor was used for aerial photography, with attached to the drone DJI Matrice 300 RTK. To perform the spatial correlation analysis, thermal infrared orthomosaics, absorbed solar radiation distribution maps were constructed, and land cover features of roof were extracted based on the drone aerial photographs. The temporal scope of this research ranged over 9 points of time at intervals of about 1 hour and 30 minutes from 7:15 to 19:15 on July 27, 2021. The correlation coefficient values of 0.550 for the normal roof and 0.387 for the cool roof were obtained on a daily average basis. However, at 11:30 and 13:00, when the Solar altitude was high on the date of analysis, the difference in correlation coefficient values between the normal roof and the cool roof was 0.022, 0.024, showing similar correlations. In other time series, the values of the correlation coefficient of the normal roof are about 0.1 higher than that of the cool roof. This study assessed and evaluated the potential of an actual cool roof to prevent solar radiation heating a rooftop through correlation comparison with a normal roof, which serves as a control group, by using high-resolution drone images. The results of this research can be used as reference data when local governments or communities seek to adopt strategies to eliminate the phenomenon of urban heat islands.

The Effects of Relational Behaviors on Supply Chain Leadership and Financial Performance: The Role of Leader Ethicality (공급체인 리더의 관계적 행동이 리더의 리더십과 팔로워의 재무성과에 미치는 영향: 리더 윤리성의 역할)

  • Kim, Sang Deok
    • Asia Marketing Journal
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    • v.13 no.3
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    • pp.183-208
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    • 2011
  • After more than 25 years of accumulated research evidence, there is little doubt that leadership behavior is related to a wide variety of positive individual and organizational outcomes. Indeed, leadership behavior has been empirically linked to increased employee satisfaction, organizational commitment, extra effort, turnover intention, organizational citizenship behavior, and overall employee performance. However, it is important to point out that although leadership behavior has been linked to a number of positive organizational outcomes, research regarding the antecedents of such behavior is limited. Especially there is little research dealing with the antecedents of inter-organizational leadership behavior. Supply chain leadership can be defined as the activities undertaken by the supply chain leader to influence the management programs and strategies of supply chain members. Supply chain performance is influenced by leadership of supply chain leader. Although research on supply chain leadership can be broadly categorized, many researchers have been preoccupied with analyzing supply chain leadership by the power-influence approach measuring such as control, power, and power bases. Also they have not examined the relationship between leadership and financial performance. This study has started to overcome those research gaps. The purpose of this study is to investigate the effect of relational behaviors on supply chain leadership, and the effect of such leadership behavior on financial performance of supply chain followers. In addition, this study also try to find out moderating variable existing in the relationship. To be concrete, First, this study develops a model of the antecedents of four conceptually distinct forms of relational behaviors such as training, fair reward, offering vision, and inter-organizational communication, and tests the hypothesized differential effects of relational behavior forms on supply chain leadership. Second, this study tests the effect of supply chain leadership on financial performance. Third, this study investigates the extent to which this leadership-performance relationship is moderated by leader ethicality. The reason why this study deals with convenience store supply chain is that there is very strong inter-dependence between a franchisor and its suppliers. Their strong inter-dependence makes their relationship as the relationship between a superior and subordinates and creates an atmosphere that leadership occur without difficulty. For the purpose of empirical testing, 217 respondents of suppliers of convenience store supply chain in Korea were surveyed and the analysis utilizing partial least square model indicated that training, fair reward, inter-organizational communication had positive effects on supply chain leadership, and such leadership had positive effect on financial performance of followers. On the other hand, offering vision had no effect on supply chain leadership. In addition, leader ethicality had moderating effect on the relationship between supply chain leadership and financial performance.

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Identifying sources of heavy metal contamination in stream sediments using machine learning classifiers (기계학습 분류모델을 이용한 하천퇴적물의 중금속 오염원 식별)

  • Min Jeong Ban;Sangwook Shin;Dong Hoon Lee;Jeong-Gyu Kim;Hosik Lee;Young Kim;Jeong-Hun Park;ShunHwa Lee;Seon-Young Kim;Joo-Hyon Kang
    • Journal of Wetlands Research
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    • v.25 no.4
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    • pp.306-314
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    • 2023
  • Stream sediments are an important component of water quality management because they are receptors of various pollutants such as heavy metals and organic matters emitted from upland sources and can be secondary pollution sources, adversely affecting water environment. To effectively manage the stream sediments, identification of primary sources of sediment contamination and source-associated control strategies will be required. We evaluated the performance of machine learning models in identifying primary sources of sediment contamination based on the physico-chemical properties of stream sediments. A total of 356 stream sediment data sets of 18 quality parameters including 10 heavy metal species(Cd, Cu, Pb, Ni, As, Zn, Cr, Hg, Li, and Al), 3 soil parameters(clay, silt, and sand fractions), and 5 water quality parameters(water content, loss on ignition, total organic carbon, total nitrogen, and total phosphorous) were collected near abandoned metal mines and industrial complexes across the four major river basins in Korea. Two machine learning algorithms, linear discriminant analysis (LDA) and support vector machine (SVM) classifiers were used to classify the sediments into four cases of different combinations of the sampling period and locations (i.e., mine in dry season, mine in wet season, industrial complex in dry season, and industrial complex in wet season). Both models showed good performance in the classification, with SVM outperformed LDA; the accuracy values of LDA and SVM were 79.5% and 88.1%, respectively. An SVM ensemble model was used for multi-label classification of the multiple contamination sources inlcuding landuses in the upland areas within 1 km radius from the sampling sites. The results showed that the multi-label classifier was comparable performance with sinlgle-label SVM in classifying mines and industrial complexes, but was less accurate in classifying dominant land uses (50~60%). The poor performance of the multi-label SVM is likely due to the overfitting caused by small data sets compared to the complexity of the model. A larger data set might increase the performance of the machine learning models in identifying contamination sources.

How Did the COVID-19 Pandemic Affect Mobility, Land Use, and Destination Selection? Lesson from Seoul, Korea

  • Lee, Jiwon;Gim, Tae-Hyoung Tommy;Park, Yunmi;Chung, Hyung-Chul;Handayani, Wiwandari;Lee, Hee-Chung;Yoon, Dong Keun;Pai, Jen Te
    • Land and Housing Review
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    • v.14 no.4
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    • pp.77-93
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    • 2023
  • The COVID-19 pandemic has brought about significant social changes through government prevention and control measures, changes in people's risk perceptions, and lifestyle changes. In response, urban inhabitants changed their behaviors significantly, including their preferences for transportation modes and urban spaces in response to government quarantine policies and concerns over the potential risk of infection in urban spaces. These changes may have long-lasting effects on urban spaces beyond the COVID-19 pandemic or they may evolve and develop new forms. Therefore, this study aims to explore the potential for urban spaces to adapt to the present and future pandemics by examining changes in urban residents' preferences in travel modes and urban space use due to the COVID-19 pandemic. This study found that overall preferences for travel modes and urban spaces significantly differ between the pre-pandemic, pandemic, and post-pandemic periods. During the pandemic, preferences for travel modes and urban spaces has decreased, except for privately owned vehicles and green spaces, which are perceived to be safe from transmission, show more favorable than others. Post-pandemic preferences for travel modes and urban spaces are less favorable than pre-pandemic with urban spaces being five times less favorable than transportation. Although green spaces and medical facilities that were positively perceived during the pandemic are expected to return to the pre-pandemic preference level, other factors of urban spaces are facing a new-normal. The findings suggest that the COVID-19 pandemic has had a significant impact on urban residents' preferences for travel modes and urban space use. Understanding these changes is crucial for developing strategies to adapt to present and future pandemics and improve urban resilience.

The Impact of the Characteristics of Start-up CEOs on the Amount of Investment in Series A Round (스타트업 CEO 특성이 시리즈 A 투자단계 벤처기업의 투자금액에 미치는 영향)

  • Choi, Sung-Woo;Han, In-Goo;Yoon, Byung-Seop
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.17 no.4
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    • pp.17-30
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    • 2022
  • The purpose of this study is to analyze the impact of the characteristics of start-up CEOs on the performance of investment attraction from the perspective of Series A investment. The results of the study are as follows. First, when the educational level of start-up CEOs was high and startup CEOs had start-up experience and investment attraction experience, venture investors such as venture capital had a significantly positive (+) effect on the investment for start-ups. This was systematically significantly positive even when control variables were introduced. When start-up CEOs had work experiences, there was no significantly positive effect on the total investment amount for start-ups but a significantly positive (+) effect on the average investment amount. Second, the standardization coefficient of total investment amount was larger in the case of start-up experience than that in the case of investment attraction experience while the standardization coefficient of average investment amount was larger in the case of investment attraction experience than that in the case of start-up experience. This suggests that the start-up experience is important for the total investment amount while the investment attraction experience is important for the average investment amount. Third, when the sales of start-ups were high at the time of Series A investment, the total investment amount and the average investment amount were also significantly high. Even if early start-ups are less profitable or have losses, the start-ups with a certain level of sales seem to be attractive investment targets for venture capital. The results of this study are useful for the investment decisions of venture capital and the financing strategies of start-ups. The implications for pre-CEOs preparing for start-ups art that the total amount of investment will increase if they have expertise through degree acquisition, challenge start-ups, gain start-up experience and implement investment attraction. Even if CEOs of start-ups do not have start-up experience, the average amount of investment for start-ups can increase if they have work experience in related industries.

Sexual Trauma Survivors and Their Mental Health: Assessing Based on Types of the Traumatic Event (성적 트라우마 경험자의 정신건강: 트라우마 사건유형에 따른 비교 분석)

  • Soyoung Choi;Hyeyun Kim;Sumi Chae
    • Health Policy and Management
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    • v.34 no.2
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    • pp.129-140
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    • 2024
  • Background: The mental health issues caused by trauma can manifest differently depending on the characteristics of the traumatic event. Particularly, individuals who have experienced sexual trauma are known to have more negative mental health outcomes compared to those who have experienced non-sexual trauma. The mental health issues of individuals who have experienced sexual trauma are severe, and new forms of threats, such as digital sexual crimes, are emerging. This study aimed to investigate whether the type of traumatic event, particularly focusing on sexual trauma events, contributes to differences in mental health outcomes and to identify factors influencing suicidal ideation and potential post-traumatic stress disorder (PTSD) risk. Methods: Based on an online survey conducted nationwide among adults aged 20 to 50, participants were categorized based on the type of trauma they experienced (sexual trauma events and non-sexual trauma events). The study conducted propensity score matching (PSM) using demographic factors (sex, age group, subjective economic status, and marital status) and resilience protective factors (cognition of recoverability, social support, and protection experiences in childhood) as control variables, excluding the experience of sexual trauma events, to investigate their potential impact on mental health (suicidal ideation and potential PTSD risk). Subsequently, binary logistic regression analysis was conducted to identify factors influencing mental health. Results: Even after PSM, individuals who experienced sexual trauma exhibited more negative outcomes in terms of suicidal ideation and potential PTSD risk compared to those who experienced non-sexual trauma. The results of binary logistic regression analysis showed that sexual trauma survivors were 1.9 times more likely to have suicidal thoughts (odds ratio [OR], 1.911) and 2.5 times more likely to have a potential PTSD risk (OR, 2.472). Furthermore, as resilience protective factors became more negative, the likelihood of suicidal ideation and potential PTSD risk increased. Conclusion: This study emphasizes the importance of understanding and supporting individuals who have experienced sexual trauma, highlighting the necessity for strategies aimed at mitigating suicidal ideation and potential PTSD risk among sexual trauma survivors, while also facilitating recovery through the promotion of resilience protective factors.

The historical study on the Ukrainian territorial conflicts: Focusing on the Crimean War and the German-Soviet War (우크라이나 영토분쟁에 관한 사(史)적 연구: 크림전쟁과 독소전쟁의 사례를 중심으로)

  • Eunchae Lee;Ikhyun Jang
    • Analyses & Alternatives
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    • v.8 no.2
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    • pp.65-86
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    • 2024
  • This study delves into the geopolitical tensions surrounding Ukraine throughout modern European history, aiming to shed light on its significance in geopolitical discourse. Since the 19th century, European powers, particularly the Anglo-Saxons and Germans, have formulated distinct geopolitical strategies concerning the Eurasian continent, with Ukraine at its focal point. The Crimean War and the German-Soviet War serve as key events to analyze these powers' geopolitical ambitions and interests. The British Empire, driven by its doctrine of thwarting land powers with sea power, intervened in the Crimean War against Russia. Its objective was to disrupt Russian dominance over Ukraine, thereby hindering Russian expansion into the Black Sea and Central Europe. On the other hand, the Third Reich of Germany, fixated on creating a European sphere exclusive from Anglo-Saxon sea powers and the Russian land power, initiated the German-Soviet War. This move aimed to secure a vast territory, including Ukraine, to facilitate expansion into the Caucasus and establish a buffer zone against the Soviet Union. Three key insights emerge from this analysis. Firstly, the absence of a dominant power rooted in Ukraine since the fall of the Principality of Kiev made geopolitical clashes inevitable. Secondly, these clashes ultimately result in a hollow victory for all involved parties, signifying the high costs and minimal gains of such confrontations. Lastly, the root cause of these clashes lies in the discord between exclusive geopolitical visions that fail to accommodate sustainable coexistence among diverse geopolitical spheres. In essence, the study underscores Ukraine's pivotal role in shaping European geopolitics and highlights the recurring clashes driven by competing visions of dominance and control over its territory. From the Crimean War to the German-Soviet War, the struggle for influence over Ukraine reflects broader geopolitical dynamics and the pursuit of strategic advantage by major powers. Ultimately, the study emphasizes the enduring significance of Ukraine in European geopolitics and the complexities inherent in managing its geopolitical tensions.