• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.1844-1846
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• 2005

The characteristic of negative differential resistance(NDR) is decreased current when the applied voltage is increased. The NDR is potentially very useful in molecular electronics device schemes. Here, we investigated the NDR property of self-assembled 4,4- Di(ethynylphenyl)-2'-nitro-1-(thioacetyl)benzene, which has been well known as a conducting molecule. Self-assembly monolayers(SAMs) were prepared on Au(111), which had been thermally deposited onto pre-treatment$(H_2SO_4:H_2O_2=3:1)$ Si. The Au substrate was exposed to a 1mM/l solution of 1-dodecanethiol in ethanol for 24 hours to form a monolayer. After thorough rinsing the sample, it was exposed to a $0.1{\mu}M/l$ solution of 4,4-Di(ethynylphenyl)-2'-nitro-1-(thioacetyl)benzene in dimethylformamide(DMF) for 30 min and kept in the dark during immersion to avoid photo-oxidation. After the assembly, the samples were removed from the solutions, rinsed thoroughly with methanol, acetone, and $CH_2Cl_2$, and finally blown dry with $N_2$. Under these conditions, we measured electrical properties of self-assembly monolayers(SAMs) using ultra high vacuum scanning tunneling microscopy(UHV-STM). The applied voltages were from -2V to +2V with 299K temperature. The vacuum condition is $6{\times}10^{-8}$ Torr. As a result, we found the NDR voltage of the nitro-benzene is $-1.61{\pm}0.26$ V(negative region) and $1.84{\pm}0.33$ (positive region), respectively.

• Textile Coloration and Finishing
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• v.7 no.4
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• pp.61-73
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• 1995

Inorganic salts have negative or positive effects on the rates of many chemical reactions and also the rates of acidic and alkaline hydrolysis of carboxylic esters. The direction of salt effects on the hydrolysis of ester depends on the charge of esters. It is expected that the rate of the alkaline hydrolysis of Poly(ethylene terephthalte)(PET), polymeric solid carboxytic polyester with carboxyl end group at the polymer end, is also influenced by inorganic salts. In the present work, to clarify the effect of divalent cations on the alkaline hydrolysis of PET, many salts with divalent cations like $MgCl_{2},CaCl_{2},SrCl_{2},BaCl_{2},$ were added to the aqueous alkaline solutions. Then PET was hydrolyzed with aqueous NaOH solution having many salts under various conditions. Some conclusions obtained from the experimental results were summarized as follows. Many salts with various divalent cations increased or decreased the reaction rate of alkaline hydrolysis of PET depending on their electrophilicity, hydration property, ability of ion pair formation, solubility, and the degree of interactions between divalent cations and anions, etc. The hydrolysis was interrupted in the order of $Ca^{+2} and was generally accelerated in the order of $Ba^{+2}. It was inferred from the increase in ΔS$^*$and the decrease in the ΔG$^*$that the divalent cations $Sr^{+2}$ and $Ba^{+2}$attracted by PET increased the collision frequency between carbonyl carbon and $OH^{-}$ion and then accelerated the reaction rate. $Mg^{+2}$and $Ca^{+2}$decreased the reaction rate because of their strong interaction with $OH^{-}$.

• Journal of The Korea Institute of Healthcare Architecture
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• v.23 no.4
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• pp.55-65
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• 2017

Purpose: This study is to identify the implications and improvement solutions to plan the local community spaces bringing empty homes back into use that fit for regional characteristics, by analyzing the Empty Home Utilization Project implemented in Nam-gu, Incheon. Methods: Among 20 homes sponsored by the Project, five homes being currently operated were analyzed in depth, and features of exterior and interior spaces, and operational characteristics of the subject homes having been renovated through the project sponsorship were examined. Results: A plan is being established to systematically manage deserted or empty homes by assigning classification to each home in Nam-gu, Incheon and they are being utilized as a community space, a place of business or a cultural art space. Most of the physical improvements only included minor repairs such as redoing interior finish, as no major renovation was implemented including layout change and wall removing. Absence of major changes including improvement of house structure resulted in problems regarding accessibility and safety. Also, there was a limit to utilize the spaces only with support on physical improvement cost for empty homes, and it was identified that positive support for renovation should be conducted in accordance with its uses for the purpose. Implications: To complete the Empty Home Utilization Project successfully, it is most critical to reflect the resident opinions and demands, and discover local operators. Furthermore, for sustainable operation of local community space, additional plans for support would be required including financial support and training local leaders, consulting support for operation, encouraging community participation, and connecting with neighbor community.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.7
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• pp.1671-1679
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• 2015

The purpose of this study is to analyze the effects of undergraduates' smart phone addiction on their development of sociality. According to the results of positive analysis, if smart phone addiction gets more serious, sociality becomes lower. More concretely, smart phone addiction consists of its subareas: difficulties in daily living, pursuing experience in the virtual world, withdrawal, and tolerance. Sociality has its subareas as confidence, sociability, and interpersonal relationship. If difficulties in daily living and tolerance become increased, confidence gets lower. In addition, as pursuing experience in the virtual world and withdrawal become increased, sociability gets lower. Regarding the dispositions of smart phone addiction in groups subdivided by sex, men are more apt to be addicted than women. Recently, smart phone use has been tremendously increased, and issues regarding addiction to it have been raised as problems in society. Therefore, it will be needed to discuss solutions for more reasonable use in society in order to prevent smart phone addiction.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.9
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• pp.4133-4137
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• 2011

Reliable Multi-Reader RFID identification is one of issues in Multi-Reader RFID realization program in recent. And the Multi-Reader RFID reader has difficulty to obtain reliable data in data capture layer. The reason is that unreliable readings such as a false positive reading and a false negative reading and missed readings can happen by reader collision problems, noise, or the mobility of tagged objects. We introduce performance metrics to solve these reader problems. We propose three solutions the Minimum Overlapped Read Zone (MORZ) with Received Signal Strength Indicator (RSSI), the Spatial-Temporal Division Access (STDA) method, and double bigger size of tags attached on the object. To show the improvement of the proposed methods, we calculate tag's successful read rates in a smart office, which consists of Multi-Reader RFID systems.

• Journal of agriculture & life science
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• v.46 no.5
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• pp.65-72
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• 2012

Salmonellosis is a widespread bacterial zoonosis that commonly causes enterocolitis and foodborne poisoning leading to an extensive economic loss in domestic animal industry. Considerably, the emergence of multidrug resistant strains of Salmonella spp. induces further severe problems affecting public health. The present report was designated to investigate the antibacterial efficacies of three common disinfectants including an oxidizing compound disinfectant (OXC), a triple salt (TS) and a quaternary ammonium compound (QAC) against Salmonella typhimurium subjected to the preliminary changes of drug temperature. All solutions of three disinfectants were pre-incubated at different temperature (22, 37 and $63^{\circ}C$) for 1 h prior to exposure to bacteria. The disinfectants and bacteria were diluted with distilled water (DW), hard water (HW) or organic matter suspension (OMS) according to treatment condition. Under the DW condition, the disinfectant efficacy of the QAC at $63^{\circ}C$ was higher than that of $22^{\circ}C$. Furthermore, under HW diluent the disinfectant efficacy of the TS pre-warmed at both of 37 and $63^{\circ}C$ were increased compared to that of $22^{\circ}C$. Considerably, the efficacy of pre-warmed QAC at both of 37 and $63^{\circ}C$ under the OMS diluent were higher than that of $22^{\circ}C$. Conclusively, prewarming at higher temperatures have positive effects on the stability of the antibacterial efficacies of TS and QAC.

• Journal of Digital Convergence
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• v.19 no.9
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• pp.201-207
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• 2021

As artificial intelligence gradually expands into jobs, iIt is necessary to nurture talents with AI literacy capabilities required for non-majors. Therefore, in this study, based on the necessity and current status of AI education, AI literacy competency improvement education was conducted for non-majors so that AI learning could be sustainable in relation to future majors. For non-majors at University D, problem-solving solutions through project-based data analysis and visualization were applied over 15 weeks, and the AI ability improvement and effectiveness of learners before and after education were analyzed and verified. As a result, it was possible to confirm a statistically significant level of positive change in the learners' data analysis and utilization ability, AI literacy ability, and AI self-efficacy. In particular, it not only improved the learners' ability to directly utilize public data to analyze and visualize it, but also improved their self-efficacy to solve problems by linking this with the use of AI.

• Journal of Convergence for Information Technology
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• v.11 no.11
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• pp.10-16
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• 2021

As the implementation of smart factories spreads widely, the need for research to improve data efficiency is raised by prioritizing massive amounts of big data using IoT devices in terms of relevance and quality. The purpose of this study is to investigate whether prioritizing big data in management accounting decisions such as cost volatility estimation and recipe optimization can improve smart solution performance and decision-making effectiveness. Based on the survey answers of 84 decision makers at domestic small and medium-sized manufacturers who operate smart solutions such as ERP and MES that link manufacturing data in real time, empirical research was conducted. As a result, it was analyzed that setting prioritization of big data has a positive effect on decision-making in management accounting. became In addition, it was found that big data prioritization has a mediating effect that indirectly affects smart solution performance by using big data in management accounting decision making. Through the research results, it will be possible to contribute as a prior research to develop a scale to evaluate the correlation between big data in the process of business decision making.

• Journal of IKEEE
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• v.25 no.3
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• pp.571-577
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• 2021

This paper describes ISO/TR 4804, an international standard to describe how to design and verify autonomous cars to ensure safety and cybersecurity. Goals of ISO/TR 4804 are (1) positive risk balance and (2) avoidance of unreasonable risk. It also 12 principles of safety and cybersecurity to achieve these goals. In the design procedures, it describes (1) 13 capabilities to achieve these safety and cybersecurity principles, (2) hardware and software elements to achieve these capabilities, and (3) a generic logical architecture to combine these elements. In the verification procedures, it describes (1) 5 challenges to ensure safety and cybersecurity, (2) test goals, platforms, and solutions to achieve these challenges, (3) simulation and field operation methods, and (4) verification methods for hardware and software elements. Especially, it regards deep neural network as a software component and it describe design and verification methods of autonomous cars.

• Perspectives in Nursing Science
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• v.16 no.1
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• pp.1-11
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• 2019

Purpose: This study was conducted to identify the perceptions toward school forest programs related to forest welfare services in elementary schools and suggest strategies to activate new programs. Methods: A mixed method research was performed. Four teachers and one forest therapist participated in a focus group interview; 162 teachers answered a survey. Results: The teachers were aware of the effects of the forest program, but there were some barriers, including the question of whether there was an accessible forest, school forest management problems, the risk of teachers' work overload, and the lack of program diversification for elementary students. Solutions included the expansion of school forests and forest facilities available to students, development of a variety of programs, provision of appropriate information on available facilities, and cooperation with educational institutions for institutionalization and increased effectiveness of school-based forest utilization programs. In addition, a scientific basis for data accumulation is needed. Conclusion: The Ministry of Forestry is cooperating with the Ministry of Education and local education offices to activate a forest-use health promotion program for elementary school students. Additionally, to utilize the forests in regular education courses, teachers should strive to spread positive awareness of forests.