• Korea Trade Review
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• v.42 no.5
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• pp.113-136
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• 2017

New product preannouncement through global supply chain management and international strategic alliances is a critical issue for firm's survive and gaining the competitive advantage in the global smart-phone market. To identify the impact of exploration alliance and exploitation alliance on the short-term's Firm Performance, respectively, This study implemented the event study and the cross sectional regression analysis, focusing on the case of Galaxy Note series. Research results identified that new technologies by exploration alliance and the existing technologies through exploitation alliance have a positive effect on the short-term's performance of vendors related. Furthermore, information for the new products showed higher the excess earning rate than information related to the existing technologies. This implies the firms that provides new technologies have a stronger innovative ability than the companies serving the existing technologies, recognizing as a positive signal in the market. Finally, this study implicates that new technologies by exploration alliance enhances innovative abilities from new product preannouncement, and is a critical variable that can determines whether to survive in the market.

• Korea Trade Review
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• v.42 no.1
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• pp.283-301
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• 2017

As a consequence of the changed role and functions in port operations, the role of port hinterland has transformed to multi-functional logistic centre linking more efficiently elements of the supply chain. This paper analysed distribution centre selection factors in Busan new port hinterland, aiming to diagnose and evaluate the operational situations of port hinterland as multi-functional logistics centre. Based on a data collected from all 122 samples located in Busan new port hinterland, determinants for location competitiveness identified were: political support, market potentiality, infrastructure utilization, market niche, and connectivity. Comparing the difference between an importance and performance, it is revealed that the target port hinterland requires urgent improvement in political supports such as incentive programmes offered by host country, free trade system and related law, financial assistance in constructing distribution centers, and simplicity, ease and efficiency of administrative procedures. The results provide useful insights for establishing future improvement strategies and a strategic agenda to successfully respond to the demands of the companies located in port hinterlands and/or new customers those who want to move in.

• Korea Trade Review
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• v.43 no.6
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• pp.51-70
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• 2018

This study is to define the relationship between capital structure and the market share in the global shipping market, estimating the debt-equity ratio. To analyze the impact of the debt-equity ratio on market share, this study collected data from the 100 largest shipping companies from 2010 to 2017. Results identified that global shipping lines moderate their debt-equity rates to 62%, and all of them strategically utilize debt in order to increase market share in global shipping market. In comparison between the group focused on cargo volume and another group focused on freight rates, it is found that the group focused on cargo volume increase their handling cargo volume through increasing the debt rates. Another group used debt rate for reducing the freight rate and enhancing market power. Furthermore, after classifying the samples into high-growth and low-growth companies, this study compared the group focused on cargo volume and another group focused on freight rates. As a result, the low-growth group showed more significant impacts of the debt rate on market share than the high-growth group. The results of this study provide useful insight for future strategic decision making of shipping lines in the global shipping market.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.386-388
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• 2021

According to data from the World Meteorological Organization (WMO) in 2019, the global average temperature between 2015 and 2019 increased by 1.1℃ compared to the pre-industrial period (1850-1900). If the average temperature rises by 1.5℃, the occurrence of natural disasters such as extreme high temperatures, heavy rains and droughts will increase, and this change will intensify depending on the speed and size of warming. Due to the effects of global warming, global surface temperatures have gradually risen, and tropical fruits, which could only be grown in tropical regions, can be seen in Korea. According to the 5th report released by the IPCC of the Intergovernmental Panel on Climate Change under the United Nations, the world's average temperature will rise 3.7 degrees Celsius at the end of the 21st century (2081-2100). If the temperature rises gradually, it is believed that Korea's current cultivation area, which can produce good quality fruit, could be turned into an unfavorable area in the future. This paper aims to develop a plant cultivation system that utilizes Arduino to provide a customized environment for the growth of plants desired by growers.

• Korean Journal of Materials Research
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• v.33 no.11
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• pp.465-474
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• 2023

The effects of La³⁺ substitution for Sr²⁺-site on the crystal structure and the dielectric properties of (Ba_0.7Sr_0.3-3x/2La_x) (Ti_0.9Zr_0.1)O₃ (BSLTZ) (0.005 ≤ x ≤ 0.02) ceramics were investigated. The structural characteristics of the BSLTZ ceramics were quantitatively evaluated using the Rietveld refinement method from X-ray diffraction (XRD) data. For the specimens sintered at 1,550 ℃ for 6 h, a single phase with a perovskite structure and homogeneous microstructure were observed for the entire range of compositions. With increasing La³⁺ substitution (x), the unit cell volume decreased because the ionic size of La³⁺ (1.36 Å) ions is smaller than that of Sr²⁺ (1.44 Å) ions. With increasing La³⁺ substitution (x), the tetragonal phase fraction increased due to the A-site cation size mismatch effect. Dielectric constant (ε_r) increased with the La³⁺ substitution (x) due to the increase in tetragonality (c/a) and the average B-site bond valence of the ABO₃ perovskite. The BSLTZ ceramics showed a higher dielectric loss due to the smaller grain size than that of (Ba_0.7Sr_0.3)(Ti_0.9Zr_0.1)O₃ ceramics. BSLTZ (x = 0.02) ceramics met the X7R specification proposed by the Electronic Industries Association (EIA).

• Korean Journal of Environmental Agriculture
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• v.42 no.4
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• pp.346-352
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• 2023

Cadusafos, an organophosphorus insecticide, has been commonly used against various pests worldwide. Organophosphorus pesticides have shorter half-lives and lower toxicities than organochlorine pesticides. However, excessive use of Cadusafos can increase pest resistance and issues with acetylcholine biomagnification, potentially resulting in human toxicity. In this study, we investigated the effect of a Cadusafos-degrading microbial agent (CDMA) prepared using Sphingobium sp. Cam5-1, which was previously reported to effectively degrade residual Cadusafos in soil. Experiments were conducted under both controlled laboratory and greenhouse field conditions. Under laboratory conditions, CDMA (10⁶ cfu/g soil application rate) decomposed 97% of Cadusafos in the soil in the untreated control after 21 days. Additionally, when CDMA (10⁶ cfu/g soil) was mixed with quicklime, 99% of Cadusafos was decomposed within 3 days. Under greenhouse field conditions, the combined effect of CDMA (10⁶ cfu/g soil) and quicklime was not observed. However, CDMA (10⁶ cfu/g soil) application alone was capable of decomposing 91% of Cadusafos after 3 days. These results indicate that CDMA can effectively decompose high residual levels of Cadusafos in soils under field conditions using a low inoculum rate.

• Therapeutic Science for Rehabilitation
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• v.13 no.1
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• pp.65-74
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• 2024

Objective : This study assessed ChatGPT, an artificial intelligence system based on a large language model, for its ability to pass the National Korean Occupational Therapy Licensure Examination (NKOTLE). Methods : Using NKOTLE questions from 2018 to 2022, provided by the Korea Health and Medical Personnel Examination Institute, this study employed English prompts to determine the accuracy of ChatGPT in providing correct answers. Two researchers independently conducted the entire process, and the average accuracy of both researchers was used to determine whether ChatGPT passed over the 5-year period. The degree of agreement between ChatGPT answers of the two researchers was assessed. Results : ChatGPT passed the 2020 examination but failed to pass the other 4 years' examination. Specifically, its accuracy in questions related to medical regulations ranged from 25% to 57%, whereas its accuracy in other questions exceeded 60%. ChatGPT exhibited a strong agreement between researchers, except for medical regulation questions, and this agreement was significantly correlated with accuracy. Conclusion : There are still limitations to the application of ChatGPT to answer questions influenced by language or culture. Future studies should explore its potential as an educational tool for students majoring in occupational therapy through optimized prompts and continuous learning from the data.

• Journal of the Korean Applied Science and Technology
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• v.41 no.3
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• pp.756-770
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• 2024

This study confirmed emulsion stability after performing antioxidant, whitening, antibacterial, and anti-inflammatory efficacy evaluation to find out the availability of Sicyos angulatus L. (SA) which is designated as an ecological disturbance species as a functional cosmetic material. SA was extracted with Deionized Water (SAW) and 70% EtOH (SAE). Compared to SAW, SAE has excellent antioxidant efficacy by showing scavenging activity and SOD-like activity against DPPH radical and ABTS⁺ radical, and inhibits melanin production by inhibiting the activity of tyrosinase. SAW had no antibacterial effect on Escherichia coli (E.c), Staphylococcus epidermidis (S.e), Staphylococcus aureus (S.a), Pseudomonas aeruginosa (P.a), and Cutibacterium acnes (C.a) strains, while SAE showed antibacterial activity by producing clear zones in E.c, S.e, P.a, and C.a strains except S.a. In LPS-treated RAW 264.7 cells, SAE showed efficacy against anti-inflammatory by inhibiting the production of NO by inhibiting the expression of iNOS and COX-2 than SAW. It was confirmed that the SAE-added emulsion was not separated at temperatures of 4℃, 25℃, and 50℃, the pH and viscosity did not change significantly in numerical terms, and the particle size was similar to that of the control emulsion, so it did not affect the formulation. Based on these results, we suggest its potential as a new material for functional cosmetics research.

• Journal of the Korea institute for structural maintenance and inspection
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• v.28 no.5
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• pp.1-9
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• 2024

Recently, the TBM tunnel construction method has been in the spotlight as tunnel excavation under urban areas such as the Metropolitan Rapid Transit (GTX) has been actively carried out. Although the construction cost of the TBM tunnel is high, it is relatively free from noise and vibration compared to the NATM tunnel method, so it is well known to be a suitable construction method for application to the lower part of urban areas. In particular, when the stratum passes through the shallow section, it can have a great impact on existing upper structures and obstacles, so accurate numerical analysis considering various variables is required when designing the TBM tunnel. Unlike other tunnel construction methods, TBM tunnels build linings by assembling factory-made segments. Unlike NATM tunnels, segment lining has connections between segments, so how to the connection status between segments is reflected can have a significant impact on securing the reliability of analysis results. Therefore, in this paper, a segment joint model(Janssen Model) was applied to the lining for seismic analysis of the TBM tunnel, and the tunnel's behavioral characteristics were analyzed after numerical analysis using nonlinear models according to urban railway seismic design standards.

• Journal of The Korean Society of Grassland and Forage Science
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• v.36 no.4
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• pp.325-332
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• 2016

The objective of this study was to determine the growth characteristics of cool ($C_1$) and warm season grasses ($C_2$) in pastures mixed with $C_1$ and $C_2$ suitable for grazing horses and effect of pastures mixed with tall and short grasses on the intake characteristics of horses. $C_1$ used in this study was Kentucky bluegrass, Redtop (short type grass) and tall type grasses were orchardgrass and tall fescue, respectively. The short type grass used as $C_2$ was Bermudagrass. This study had the following four treatment groups: 1) Treatment 1 (Bermudagrass + Kentucky bluegrass + Redtop) 2) Treatment 2 (Bermudagrass + tall fescue + orchardgrass) 3) Treatment 3 (Kentucky bluegrass + Redtop) 4) Treatment 4 (tall fescue + orchardgrass). There was no winterkilling or lodging problem at an altitude of 200 m. Plant heights in mixed pasture of Treatment 1, 2, 3, and 4 were 53.9, 58.2, 57.5, and 78.1 cm, respectively. Plant height was the highest in Treatment 4. Dry matter yield was in the following order : Treatment 4 > Treatment 3 > Treatment 2 > Treatment 1. In the first investigation regarding vegetation distribution, Bermudagrass ratios among grasses in Treatment 1 and Treatment 2 were 70% and 66.7%, respectively. Overall, other grasses showed poor growth. In the second investigation of vegetation distribution, Bermudagrass ratios among grasses in Treatment 1 and Treatment 2 were 80% and 60.7%, respectively. Crude protein content, neutral detergent fiber content, acid detergent fiber content, digestibility value, and nutritive values were the lowest in Treatment 4, followed by those in Treatment 1, Treatment 2 and Treatment 3.