• Journal of the Korean Society for Aviation and Aeronautics
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• v.28 no.1
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• pp.90-105
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• 2020

This research investigates the export strategy for pioneering a new market of Advanced Pilot Trainer T-50, a business unit of KAI company, and increasing its market share. The export strategy is proposed based on the Corporate Marketing Model along with the market oriented concept. Specific sales strategies are extracted in consideration of product analysis, market analysis, and integration of product and target market. Therefore, six countries in Africa are selected as the primary target markets on account of their market potentials. In addition, T-50 is repositioned to 'T-50Af' as 'high price competitive and multi-role trainer.' The business implications include the expansion of the market in Africa and the pursuit of the consistent development and growth of T-50.

• International Journal of Fluid Machinery and Systems
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• v.8 no.4
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• pp.311-317
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• 2015

It is difficulty to calculate velocity circulation in centrifugal pump impeller outlet accurately. Velocity circulations of a double-blade pump impeller outlet were calculated with Stodola formula, Weisner formula and Stechkin formula. Simultaneously, the internal flow of impeller for the double-blade pump were measured with PIV technology and average velocity circulations at the 0.8, 1.0 and 1.2 times of design flow were obtained. All the experimental values were compared with the above calculation values at the three conditions. The results show that calculation values of velocity circulations with Weisner formula is close to the experimental values. On the basis of the above, velocity circulations of impeller outlet were corrected. The results of experimental verification show that the corrected calculation errors, whose maximum error is 3.65%, are greatly reduced than the uncorrected calculation errors. The research results could provide good references for establishment of theoretical head and multi-condition hydraulic optimization of double-blade pumps.

• Journal of Power Electronics
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• v.18 no.1
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• pp.129-136
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• 2018

An accurate state-of-charge (SOC) estimation ensures the reliable and efficient operation of a lithium-ion battery management system. On the basis of a combined electrochemical model, this study adopts the forgetting factor least squares algorithm to identify battery parameters and eliminate the influence of test conditions. Then, it implements online SOC estimation with high accuracy and low run time by utilizing the low computational complexity of the unscented Kalman filter (UKF) and the rapid convergence of a particle filter (PF). The PF algorithm is adopted to decrease convergence time when the initial error is large; otherwise, the UKF algorithm is used to approximate the actual SOC with low computational complexity. The effect of the number of sampling particles in the PF is also evaluated. Finally, experimental results are used to verify the superiority of the combined method over other individual algorithms.

• Kyungpook Mathematical Journal
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• v.49 no.2
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• pp.235-243
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• 2009

In this paper, we deal with the problem of uniqueness of meromorphic functions that share two small functions with their derivatives, and obtain the following result which improves a result of Yao and Li: Let f(z) be a nonconstant meromorphic function, k > 5 be an integer. If f(z) and g(z) = $a_1(z)f(z)+a_2(z)f^{(k)}(z)$ share the value 0 CM, and share b(z) IM, $\overline{N}_E(r,f=0=F^{(k)})=S(r)$, f${\equiv}$g, where $a_1(z)$, $a_2(z)$ and b(z) are small functions of f(z).

• Journal of Power Electronics
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• v.19 no.1
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• pp.58-67
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• 2019

This study presents a new portable eight-output light emitting diode (LED) driver. The eight output-channels are divided into two equal groups, and their output powers can be controlled individually by three active switches. In addition, a simple capacitor-based passive current balancing circuit (CBC) is employed in each port to guarantee that the currents of the four LEDs are the same. When compared with the conventionally used separate two-output isolated converters, the proposed one uses one less active switch. Moreover, zero-voltage-switching (ZVS) is achieved, which improves the power efficiency of the driver. Finally, a highly compact prototype is built, which can reach an efficiency of 94.6%.

• International Journal of Computer Science & Network Security
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• v.21 no.1
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• pp.214-219
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• 2021

As the number of elderly increased rapidly every year, many elderly still choose to stay independent despite of difficulties and challenges faced in their daily routine. Elderly has desperate needs for support for their living. Internet of Things helps to support and improve elderly's life in many ways to meet the needs and requirements. Home Automation Control (EHAC) is a research based system that support elderly with controlled automation solution that control and operates various home electrical appliances based on the measurement of heart pulse rate and environment temperature. This paper works on EHAC system to evaluate the performance of the system in elderly's daily routine. This paper presented experiments conducted with approach of IoT testing and discussion on analysis of the results.

• Journal of the Korean Mathematical Society
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• v.59 no.1
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• pp.129-150
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• 2022

Let L = -∆ + V be a Schrödinger operator, where the potential V belongs to the reverse Hölder class. In this paper, by the subordinative formula, we investigate the generalized Poisson operator P^L_t,σ, 0 < σ < 1, associated with L. We estimate the gradient and the time-fractional derivatives of the kernel of P^L_t,σ, respectively. As an application, we establish a Carleson measure characterization of the Campanato type space 𝒞^𝛄_L (ℝⁿ) via P^L_t,σ.

• Review of KIISC
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• v.32 no.4
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• pp.77-84
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• 2022

2020년 8월 5일 통합 개인정보보호법 [3]이 본격적으로 시행되면서 데이터의 보호와 활용을 동시에 만족할 수 있는 가명처리 개념이 도입되었다. 여러 개인정보처리자로 수집된 가명정보를 결합하기 위한 결합 관리기관이 지정되고 있다. 개인정보보호 국제표준은 관행이나 기술을 국제표준으로 개발하여 상호 연동이 가능한 서비스를 제공할 수 있을 뿐만 아니라 제품이나 서비스의 경쟁력을 강화하는데 활용할 수 있다. 개인정보보호 국제표준화를 주도적으로 추진하고 있는 대표적인 국제표준화 그룹은 국제표준화위원회/전기위원회 합동위원회 1/서브위원회 27/작업그룹 5 (ISO/IEC JTC 1/SC 27/WG 5)를 들 수 있다. 이 그룹의 의장님 독일 쾨테대학 Kai Rannenberg 교수가 맡고 있다. 여기서는 2020년 4월 전자회의 이후에는 개인정보보호 분야 3건의 국제표준을 채택하였다. 차기 회의는 2022년 9월 룩셈부르그에서 펜데믹 이후 최초로 대면과 비대면으로 개최될 예정이다. 본 고에서는 이 그룹에서 2020년 4월 이후 추진되고 있는 개인정보보호 관련 국제표준화 동향을 제시하고자 한다. 또한 지난 4월 SC27 WG5 전자 회의에서 논의된 개인정보보호 관련 주요 표준화 이슈와 대응 방안을 제시한다.

• Asia Pacific Journal of Corpus Research
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• v.3 no.1
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• pp.21-34
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• 2022

This study aims to apply corpus-based approach to analyze The Yellow Wall-Paper and Herland written by Charlotte Perkins Gilman, a women's rights activist in the late nineteenth-century America. Although both works have attracted feminists' attention to the woman question that concerned Gilman, discussion on her language features and their relation to the literary themes of these two works is still in need. In this corpus-based analysis, we argue that the main themes of different literary works can be revealed through linguistic patterns identified by number and gender features of nouns and pronouns in the contrast of two works and a balanced corpus. The linguistic features (number and gender) have been related with two themes, the 'group and individual' and the 'feminine and masculine', and are further interpreted in terms of mothering and feminine consciousness. By adopting linguistic approach, our study provides quantitative and qualitative evidence to verify the established themes and arguments of these literary texts.

• Journal of Information Processing Systems
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• v.19 no.1
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• pp.1-16
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• 2023

Synthetic data generation is generally used in performance evaluation and function tests in data-intensive applications, as well as in various areas of data analytics, such as privacy-preserving data publishing (PPDP) and statistical disclosure limit/control. A significant amount of research has been conducted on tools and languages for data generation. However, existing tools and languages have been developed for specific purposes and are unsuitable for other domains. In this article, we propose a regular expression-based data generation language (DGL) for flexible big data generation. To achieve a general-purpose and powerful DGL, we enhanced the standard regular expressions to support the data domain, type/format inference, sequence and random generation, probability distributions, and resource reference. To efficiently implement the proposed language, we propose caching techniques for both the intermediate and database queries. We evaluated the proposed improvement experimentally.