• Nonlinear Functional Analysis and Applications
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• 제28권2호
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• pp.537-555
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• 2023

In this paper, we consider two types of fractional boundary value problems, one of them is an implicit type and the other will be an integro-differential type with nonlocal integral multi-point boundary conditions in the frame of generalized Hilfer fractional derivatives. The existence and uniqueness results are acquired by applying Krasnoselskii's and Banach's fixed point theorems. Some various numerical examples are provided to illustrate and validate our results. Moreover, we get some results in the literature as a special case of our current results.

• Nonlinear Functional Analysis and Applications
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• 제28권4호
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• pp.943-956
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• 2023

Let p(z) be a polynomial of degree n and for any complex number 𝛽, let D_𝛽p(z) = np(z) + (𝛽 - z)p'(z) denote the polar derivative of the polynomial with respect to 𝛽. In this paper, we consider the class of polynomial $$p(z)=(z-z_0)^s \left(a_0+\sum\limits_{{\nu}=0}^{n-s}a_{\nu}z^{\nu}\right)$$ of degree n having a zero of order s at z₀, |z₀| < 1 and the remaining n - s zeros are outside |z| < k, k ≥ 1 and establish upper bound estimates for the maximum of |D_𝛽p(z)| as well as |p(Rz) - p(rz)|, R ≥ r ≥ 1 on the unit disk.

• Journal of Information Technology Applications and Management
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• 제28권5호
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• pp.17-39
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• 2021

Indonesia's industrial application of digital technology is growing fast, especially in the application of mobile technology. About 1,700 digital startups are sprouting. PT Aplikasi Karya Anak Bangsa is one of those digital startups founded in 2010. This company is widely known, especially in Southeast Asia, for its products and services called 'Gojek' which was launched initially in 2015. Gojek began as a ride-hailing mobile-based application that later evolved into a Super App providing more than 20 different services in one single mobile application. After becoming Indonesian first unicorn company in 2016, Gojek now has become the first decacorn company in Indonesia, worth more than USD 10 billion since 2019. This paper aims to analyzes the technology industry in Indonesia and analyzes Gojek's background and history, its competitive status, and critical success factors. As a conclusion, we provide some advices for future development of Gojek in Indonesia and other countries in Southeast Asia's market. The advices include rebranding its overseas presence and the use of consistent brand identity across countries.

• East Asian mathematical journal
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• 제28권2호
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• pp.159-172
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• 2012

In all Mathematics I Textbooks(Kim, S. H., 2010; Kim, H. K., 2010; Yang, S. K., 2010; Woo, M. H., 2010; Woo, J. H., 2010; You, H. C., 2010; Youn, J. H., 2010; Lee, K. S., 2010; Lee, D. W., 2010; Lee, M. K., 2010; Lee, J. Y., 2010; Jung, S. K., 2010; Choi, Y. J., 2010; Huang, S. K., 2010; Huang, S. W., 2010) in high schools in Korea these days, it is written and taught that for a positive real number $a$, $a^{\frac{m}{n}}$ is defined as $a^{\frac{m}{n}}={^n}\sqrt{a^m}$, where $m{\in}\mathbb{Z}$ and $n{\in}\mathbb{N}$ have common prime factors. For that situation, the author shows his opinion that the definition is not well-defined and $a^{\frac{m}{n}}$ must be defined as $a^{\frac{m}{n}}=({^n}\sqrt{a})^m$, whenever $^n\sqrt{a}$ is defined, based on the field axiom of the real number system including rational number system and natural number system. And he shows that the following laws of exponents for reals: $$\{a^{r+s}=a^r{\cdot}a^s\\(a^r)^s=a^{rs}\\(ab)^r=a^rb^r$$ for $a$, $b$>0 and $s{\in}\mathbb{R}$ hold by the completeness axiom of the real number system and the laws of exponents for natural numbers, integers, rational numbers and real numbers are logically equivalent.

• 한국과학교육학회지
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• 제28권8호
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• pp.814-822
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• 2008

This study plans to develop strategies using children's verse in science education and investigate the effects of instruction using children's verses on the attitude toward science. The study tried to determine strategies using children's science verse in order to find out their value. For the purpose of this, two classes of the 6th grade were selected in an elementary school for tests. The results from this research showed that strategies using children's verse in science education were developed and applied in teaching/learning purposes as well as in the area of literature. A strategy for remembering was applied widely. A strategy for understanding scientific principles and for quest methods, writing children's science verses directly helped in scientific conceptual formation. Instruction using children's science verses had a positive effect on the attitudes toward science. Students maintained positive attitudes throughout instruction that used children's science verses. In conclusion, instruction using children's science verses can be applied to science education, and the attitudes toward science and learning achievements can be improved.

• Parasites, Hosts and Diseases
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• 제55권3호
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• pp.327-331
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• 2017

A fly larva was recovered from a boil-like lesion on the left leg of a 33-year-old male on 21 November 2016. He has worked in an endemic area of myiasis, Uganda, for 8 months and returned to Korea on 11 November 2016. The larva was identified as Cordylobia anthropophaga by morphological features, including the body shape, size, anterior end, posterior spiracles, and pattern of spines on the body. Subsequent 28S rRNA gene sequencing showed 99.9% similarity (916/917 bp) with the partial 28S rRNA gene of C. anthropophaga. This is the first imported case of furuncular myiasis caused by C. anthropophaga in a Korean overseas traveler.

• 한국안전학회지
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• 제28권3호
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• pp.23-28
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• 2013

This study focuses on finding ways to derive train's optimal ECO driving pattern, which can improve the ride quality and reduce driving energy consumption with keeping the time interval between the stations. As research method, we compared difference of currently operating train's ATO and MCS driving patterns, and concentrated upon the things need to consider in simulation in order to improve the existing pattern of ATO driving pattern's issues with securing the train operation safety. Determining driving pattern minimizing energy consumption by controlling powering within speed limit and controlling switching to coasting at appropriate point considering the track conditions for each section, and determining braking control starting time considering ride comfort and precise stopping is considered to be most important.

• Parasites, Hosts and Diseases
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• 제42권3호
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• pp.129-135
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• 2004

We compared the DNA sequences of the genus Metagonimus: M. yokogawai, M. takahashii, and M. miyatai. We obtained 288 D1 ribosomal DNA (rDNA) and mitochondrial cytochrome c oxidase subunit I (mtCOI) fragments from the adult worms by PCR, that were cloned and sequenced. Phylogenetic relationships inferred from the nucleotide sequences of the 28S D1 rDNA and mtCOI gene. M. takahashii and M. yokogawai are placed in the same clade supported by DNA sequence and phylogenie tree analysis in 28S D1 rDNA and mtCOI gene region. The above findings tell us that M. takahashii is closer to M. yokogawai than to M. miyatai genetically. This phylogenetic data also support the nomination of M. miyatai as a separate species.

• Journal of Biosystems Engineering
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• 제28권2호
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• pp.89-96
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• 2003

This study was aimed to identify how the main body vibration of power tiller will be transmitted to the trailer, and to find out the basic information for demage reducing method of agricultural products during transportation. The vertical vibration acceleration level was measured at 6 positions, i.e. engine, hitch, seal and three parts of trailer (front middle, and rear) for the not driving but at the engine speeds of 1,000rpm and driving at 0.35m/s. The results of this research could be summarized as follows; 1. For not driving, the accumulated acceleration level up to 120Hz was 50% of total accelerations at engine part and those were 28~41% at other parts. Those up to 40Hz were 20~30% at engine and hitch part and 2~8% at trailer part. And those up to 20Hz were 13~20% at engine and hitch part and 1~4% at trailer part 2. For the driving with 0.35m/s at paved road, the average vertical accelerations were in the range of 0.005~0.058m/s$^2$. The lowest value of 0.005m/s$^2$ was showed at engine part and the value of 0.031-0.058m/s$^2$ was showed at trailer part. 3. For the driving with 0.35m/s, the accumulated value of average vertical accelerations showed the lowest value at engine parts md showed 5 times value of engine part at trailer part especially highest value at middle part of trailer. 4. For the driving with 0.35m/s, the accumulated acceleration level up to 120Hz was 75% of total accelerations at engine part and those were 20~42% at other parts. Ant those up to 20Hz and 40Hz were 24~26% at engine part and 0.1~0.6% at trailer part.

• 건축역사연구
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• 제28권3호
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• pp.19-28
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• 2019

The purpose of this study is to identify the form and components, decoration and locality of pyongnangans(平欄干) in Yangban's Houses(32 Houses) in Gyeongbuk region, The results of this study, which were carried out through both survey and on-site study, are as below. First, Pyongnangans of Gyeongbuk region Yangban's Houses can be classified into 4 different types, which are (1)Mureum type, (2)Gyoran(交欄) type, (3)Mureum-Saldae combination type, (4)Simplified Saldae type. And these 4 types are again subdivided into eight types, depending on differences of both detailed form and framework. Gyoran type are the most common cases in Yangban's Houses of Gyeongbuk region, whose number is followed by the order of Mureum type, Mureum-Saldae combination type and Simplified Saldae type Pyongnangans. Decorative 亞 shaped Gyoran type are more set up in Sarangchaes than in Anchaes, and this was because Decorative Gyorans are more appropriate to show the Social status and class of a patriarch than humble Mureum type. Pyongnangans of Yangban's Houses in Gyeongbuk region have their peculiarities in the exclusion of decorativeity, by consistent use of plain single-layer Pyongnangans. A certain locality is reflected on the types and detailed forms of Pyonnangans. Mureum type are widely found in Gyeoungju region Yangban's Houses, while Gyoran type were more often used in Andong region. In Bonghwa region, Mureum-Saldae combination type are found in large quantities. This was due to the locational chateristics of Sarangchaes in Bonghwa region, which were usually built on steep slopes.