• Journal of Applied Biological Chemistry
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• v.63 no.3
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• pp.267-274
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• 2020

The dissipation characteristics and kinetics of fungicide mandipropamid and insecticide thiamethoxam in lettuce under greenhouse conditions were investigated at three different lettuce-growing fields for estimating the pre-harvest residue limits (PHRLs). The analytical methods were fully validated for the quantitation of pesticide residues using High-Performance Liquid Chromatography-Photo Diode Array detector or Ultraviolet-Visible Detector and applied to real samples. The lettuces suitable for shipment were harvested during 10 days including pre-harvest interval after treatment at the recommended dose by safe-use guidelines. The initial mean residues in different fields were 6.68-17.87 and 4.96-8.31 mg/kg for mandipropamid and thiamethoxam, respectively, which decreased to 16-54 and 14-44% in 10 days. The clothianidin, a metabolite of thiamethoxam, was detected in <0.02 to 0.37 mg/kg. The dissipation of both pesticides followed first-order kinetics over a period of 10 days after application. Based on the residue data, the mean dissipation rate constant (λ) and biological half-lives (T_1/2) were estimated to be -0.1060 and 6.5 days of mandipropamid and -0.1236 and 5.6 days of thiamethoxam. The PHRLs for lettuce on the 10th and 5th day before harvesting were calculated to be 63.24 and 43.56 mg/kg for mandipropamid, and 44.66 and 25.88 mg/kg for thiamethoxam, with -0.0746 and -0.1091 of the upper 95% confidence intervals of dissipation rate constant, respectively. This work would be useful as guidance for adjusting the shipment date and contribute to stabilizing the income of farmers in Korea.

• Korean Journal of Agricultural and Forest Meteorology
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• v.18 no.1
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• pp.16-29
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• 2016

The total area of paddy field was estimated to be 55 % of the cultivated lands in South Korea, which is approximately 1 million hectares. Organisms inhabiting paddy fields if they are sensitive to environmental changes can be environmental indicator of paddy fields. Biological indicators such as phenology and distributional range are evaluated as intuitive and quantitative method to analyze the impact of climate change. This study aims to estimate flight time change of Hydrophilidae species' based on the RCP 8.5 climate change scenario. Unmanned monitoring systems were installed in Haenam, Buan, Dangjin and Cheorwon relative to the latitudinal gradient. In the three regions excepting Cheorwon, it was able to measure the abundance of flying Hydrochara affinis and Sternolophus rufipes. Degree-day for the flight time was determined based either on field measurement values and estimates of 2020s, 2050s and 2080s from KMA climate change scenario data. As a result, it is found that date of both species of initial flight becomes 15 days earlier, that of peak flight becomes 22 days earlier and that of final flight does 27 days earlier in 2080s compared to 2020s. The climate change impact on flight time is greater in coastal area, rural area and valley than inland area, urban area and plan. H. affinis and S. rufipes can be used as climate change indicator species.

• Journal of Distribution Science
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• v.13 no.12
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• pp.53-63
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• 2015

Purpose - Recently, creating shared value (CSV) has attracted attention through plan sustainability and the growth of corporate management. Porter and Kramer (2011) defined the core concept of CSV as social value, economic profits, improvements in the economic social condition, and reinforcing competitiveness. The purpose of CSV, which is to pursue economic profits through a social solution to the problem, agrees with managing the objective of a social enterprise that prioritizes the pursuit of profits through the realization of a social purpose. Today, CSV studies focus on CSR and sustainability and reinforce competitiveness. However, few studies focused on the social economy. Precedent studies examined CSV using a company example, and few studies exist from the perspective of consumers and the point of view of a market society. Research design, data, and methodology - Therefore, this study examines CSV in comparison to a background of the social economy. This study also investigates and analyzes the concept of social value from the point of view of consumers, social problems, consumption value, corporate value, and the influence of consumers. This article develops three hypotheses. Hypothesis 1 investigates the correlation with social innovation that consumers thought as being necessary for social innovation by a company. Hypothesis 2 is used to confirm the influence of consumers in CSV. Therefore, this article investigates the influence of consumers on consumption action for companies that are indifferent to social problems. Hypothesis 3 is used to verify the correlation between the value that consumers demand through consumption and the corporate value that companies pursue other than profits. The three hypotheses were adopted and met the standard for suitability. Results - The importance of the CSV study from the consumer perspective was confirmed using the influence of consumers on CSV. Because the objective of company activities is either the consumer or the market, the influence that extends to interactions between the company and consumers to ensure the success of a business is significant. Regarding the CSV study, because it was an initial study, various approaches are subsequently developed. However, conceptual and practical case studies on CSV currently exist that may be used to verify the factors that comprise CSV. Therefore, the company example may enable verification of the factors that influence the composition of CSV through identification from the consumer perspective. In addition, studying CSV as an action result (of consumer satisfaction, of a company's profits and competitiveness, and of society's cancellation of a social problem) may enable the realization of a practice paradigm as opposed to simply thought and faith. Conclusions - First, this study confirms the social value of a business through the feasible and common pursuit of consumers by corporations. Second, customer influence accounts for an important part of CSV. Third, shared value commonly provides a necessary advantage to consumers, corporates, and society, and contributes to the economy and healthy social development. Fourth, corporates can conduct a business, generate profits, and realize value through improvements in social problems and by addressing their competitive strengths and weaknesses.

• Journal of Distribution Science
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• v.13 no.12
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• pp.105-111
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• 2015

Purpose - Many global companies across industries are paying significant attention to co-creation activities, which enable consumers to participate in firms' value creation process, as a main model of new product development processes. In this study, we aim to examine different types of co-creation activities and their effects on consumer attitudes. We focus on upstream co-creation, downstream co-creation, autonomous co-creation, and sponsored co-creation. Upstream co-creation includes firms' control and management in the initial stage of new product development and prototype testing. Downstream co-creation indicates that consumers participate in firms-initiative activities at a later stage in new product development, such as public relations and marketing communications. Autonomous co-creation includes consumers' commitment activities in the absence of firms' rewards. However, under the sponsored co-creation, consumers can return monetary and social rewards from firms through their co-creation activities. The hypotheses regarding the effect of co-creation on consumer attitudes are as follows. (H1, H2, H3, H4) Upstream, downward, autonomous, and sponsored co-creation has positive effects on consumer attitude. (H5, H6) As intrinsic motivation increases, the positive effect of upstream and autonomous co-creation increases. (H7, H8) As extrinsic motivation increases, the positive effect of downward and sponsored co-creation increases. Research design, data, and methodology - To achieve our research goals, we analyzed responses from 246 samples from Korean consumers and verified the proposed hypotheses using a linear regression model. The samples include Korean consumers who experienced upstream, downstream, autonomous, and sponsored co-creation by firms. Results - First, both upstream co-creation and downstream co-creation with firms and consumers are found to have positive effects on consumer attitudes. Second, autonomous co-creation and sponsored co-creation are found to positively affect consumer attitudes. Third, consumers' intrinsic motivation has a fit-effect between upstream co-creation and autonomous co-creation, and their extrinsic motivation has a fit-effect between downstream co-creation and sponsored co-creation. Consumers who have strong intrinsic motivation are affected by upstream co-creation and autonomous co-creation. However, consumers who have strong extrinsic motivation are affected by downstream co-creation and sponsored co-creation. Conclusion - These results indicate that the fit between consumers' co-creation participation types and consumers'motivations is a significant factor in determining consumer attitudes. The results of this study imply that various types of consumer participation actually improve consumers' attitudes toward products and brands. In addition, our study also suggests that firms should consider the fit between co-creation types and consumers' motivations when they initiate co-creation activities. In this study, we survey consumers who participated in firms' co-creation activities. Future studies can compare different types of consumers. For instance, we can examine the different in different test by comparing experienced versus inexperienced consumers. Finally, we expand this research to user-generated content topics. This attending issue focuses on the mechanism that breaks down the boundaries and barriers between consumers and producers.

• Journal of Distribution Science
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• v.16 no.9
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• pp.65-77
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• 2018

Purpose - A trading area is very closely related to consumer life. A trading area is a cultural and social space that consumes culture and promotes human relationships as well as an economic space where consumers live their daily lives. In this context, a trading area research should be conducted objectively and empirically because it deals with the activities of consumer's life. The purpose of this study is to identify the intrinsic psychological motivation(push motivation) caused when consumers visit a trading area and to demonstrate how the push motivation for a trading area influence on consumer's flow, satisfaction, revisit intention. Research design, data, and methodology - In order to develop research hypotheses for this study, the development procedures for push motivation scale are as follows; (1) generating initial pool of items based on previous studies, (2) expert judgement to evaluate content and face validity, and (3) assessing convergent and discriminant validity using confirmatory factor analysis. In order to achieve these purposes, online surveys were conducted on frequent or familiar visitors to the trading areas around the Gangnam, Kunkuk University and Hongik University Station. Among the 1,343 questionnaires collected, 1,157 cases were analyzed by using SPSS 22.0 and SmartPLS 3.0 statistical package program, except for 186 responses in which responses were judged to be unfaithful. Results - The push motivation was classified into five sub-dimensions of excitement/stimulus, rest/relaxation, exit/refreshing, knowledge/learning and human relationship promotion as multidimensional and complex factors composed of individual and social-related dimensions. The excitement/stimulus and human relationship promotion of push motivation have positive effects on satisfaction. However, all dimensions of the push motivation have positive effects on flow. And flow has a positive effect on satisfaction and revisit intention. Meanwhile, the mediation test using boostrapping shows that flow plays a full mediating role in the relationship between rest/relaxation, exit/refreshing, knowledge/learning and satisfaction, but a partial mediating rol e between excitement/stimulus, human relationship promotion and satisfaction. Finally, satisfaction plays a partial mediating role between flow and revisit intention. Conclusions - This study shows that the push motivation is multidimensional and compositive depending on the situation of a consumer. In addition, it is found that the human relationship promotion(a social-related motivation) has a much more important effect on flow and satisfaction than other push motivations of individual dimensions. It also shows that satisfaction increases when consumers are being flowed at their visit and degree of revisit intention also grows as satisfaction increases. As implications of this study, a marketer should try to understand consumer's visit motivation at first and then develop factors that increase their flow, satisfaction, revisit intention. It also requires a marketer to approach subjects on a trading area more objectively and empirically based on the psychology and behavior of consumers, in order to establish a proper and efficient strategy on development of a trading area.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.49 no.1
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• pp.19-30
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• 2012

For digital data compression, the quantization is the main part of the lossy source coding. In order to improve the performance of quantization, the vector quantizer(VQ) can be employed. The encoding complexity, however, exponentially increases as the vector dimension or bit rate gets large. Much research has been conducted to alleviate such problems of VQ. Especially for high bit rates, a constrained VQ, which is called the sample-adaptive product quantizer(SAPQ), has been proposed for reducing the hugh encoding complexity of regular VQs. SAPQ has very similar structure as to the product VQ(PQ). However, the quantizer performance can be better than the PQ case. Further, the encoding complexity and the memory requirement for the codebooks are lower than the regular full-search VQ case. Among SAPQs, 1-SAPQ has a simple quantizer structure, where each product codebook is symmetric with respect to the diagonal line in the underlying vector space. It is known that 1-SAPQ shows a good performance for i.i.d. sources. In this paper, a study on designing 1-SAPQ for the first-order Markov process. For an efficient design of 1-SAPQ, an algorithm for the initial codebook is proposed, and through the numerical analysis it is shown that 1-SAPQ shows better quantizer distortion than the VQ case, of which encoding complexity is similar to that of 1-SAPQ, and shows distortions, which are close to that of the DPCM(differential pulse coded modulation) scheme with the Lloyd-Max quantizer.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.45 no.1
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• pp.37-47
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• 2008

Exploitation of address generation units which are typically provided in DSPs plays an important role in DSP code generation since that perform fast address computation in parallel to the central data path. Offset assignment is optimization of memory layout for program variables by taking advantage of the capabilities of address generation units, consists of memory layout generation and address pointer assignment steps. In this paper, we propose an effective address pointer assignment method to minimize the number of address calculation instructions in DSP code generation. The proposed approach reduces the time complexity of a conventional address pointer assignment algorithm with fixed memory layouts by using minimum cost-nodes breaking. In order to contract memory size and processing time, we employ a powerful pruning technique. Moreover our proposed approach improves the initial solution iteratively by changing the memory layout for each iteration because the memory layout affects the result of the address pointer assignment algorithm. We applied the proposed approach to about 3,000 sequences of the OffsetStone benchmarks to demonstrate the effectiveness of the our approach. Experimental results with benchmarks show an average improvement of 25.9% in the address codes over previous works.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.11
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• pp.180-187
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• 2013

The dinger in solar generation is the amount of sunlight which the solar cells absorb. Various types of solar trackers, which rotate themselves in order to make the solar cells face the sun as much as possible, have been developed, and especially the method of tracking with two axes has greatly contributed in increasing the generation amount at work sites. Among theses 2-axis solar trackers, the inclination-dependent 2-axis solar tracker are widely utilized for its advantages of requiring less initial investment and easy maintenance due to a solid structure. However, the drawback is that the generation efficiency is relatively low because of the structural restriction that limits the rotation angle, thus making it less efficient when tracking the sun. This paper proposes a method to increase the generation efficiency of the inclination-dependent 2-axis solar tracker. It also contains the derived equations needed for precise controlling along with a method to keep tracking with the other axis even when one has reached its angle limit. To confirm that the proposed method increases the amount of incidence onto the solar cells, formulas needed for operation on the proposed method and tracking the exact position of the sun are derived, and applying this to the quarterly data of Korea Astronomy and Space Science Institute it shows maximum over 11.1% more incidence compared to existing methods.

• Bulletin of the Society of Naval Architects of Korea
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• v.27 no.4
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• pp.58-66
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• 1990

A series of test was performed measuring the failure strength and failure mode of Gr/Pi, $[0^{\circ}/45^{\circ}/90^{\circ}/-45^{\circ}]_s$ laminate containing a single pin loaded hole. The finite element method is applied to calculate the stress distribution in the laminates, then the failure load and the failure mode were predicted by means of the characteristic length. 12 different geometric variations were developed to analyze the effects of the ratio of specimen width to hole diameter (W/d) and ratio of edge distance to hole diameter (L/d). X-Ray of NDE methods were utilized in finding out the initial defects, damage and the fracture mechanism, and SEM(Scanning Electron Microscopes) was used the evaluation of the fracture mechanism and crack propagation around hole under tension pin loading. $[0^{\circ}/45^{\circ}/90^{\circ}/-45^{\circ}]_s$ laminate are found to be most sensitive to W/d but not so influenced by L/d. The failure mode and tensile strength predicted by the model show agreement with experiment data for pin loading bolted jointed test except range of $L/d{\leqq}3$.

• Journal of the Korea Concrete Institute
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• v.17 no.6 s.90
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• pp.993-1000
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• 2005

Various types of FRP materials have been applied for structural strengthening of RC beams in various forms. When CFRP plates are used, a premature failure used to occur before enough strengthening effect appears. This is primarily due to the rip-off of CFRP Plate attached on RC beams. Despite of numerous studies on the rip-off failure of externally strengthened RC beams, its failure mechanism is not definitely clarified yet. Investigations from literatures have shown that the rip-off failure is dependant on the vertical and shear stresses at the level of main reinforcements in RC beams. This study suggests an analytical model to Investigate the rip-off failure load based on the stress states at the level of main reinforcements. The proposed model is relatively simple and produces very comparable results to the test data. It is believed that the proposed model can be successfully used to provide more information on the rip-off failure mechanisms and its prevention.