• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.2
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• pp.114-123
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• 2005

A nonlinear speed control of a PMSM using a sequential parameter auto-tuning algorithm for servo equipments is presented. The nonlinear control scheme gives an undesirable output performance under the mismatch of the system parameters and load conditions. Recently, to improve the performance, an adaptive linearization scheme, a sliding mode control and an observer-based technique have been reported. Although a good performance can be obtained, the performance is not satisfactory any more under specific conditions such as a large inertia variation, a fast speed transient or an increased sampling time. The simultaneous estimation of principal parameters giving a direct influence on speed dynamics is generally not simple. To overcome this problem, a a sequential parameter auto-tuning algorithm at start-up is proposed, where dominant parameters are estimated in a prescribed regular sequence based on the method that one parameter is estimated during each interval. The proposed scheme is implemented on a PMSM using DSP TMS320C31 and the effectiveness is verified through simulations and experiments.

• Industry Promotion Research
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• v.2 no.2
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• pp.23-29
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• 2017

This study aims to suggest a new method to escape crisis of manufacturing industry. We focused on the field - oriented management innovation promotion performance divided into qualitative performance and quantitative performance. The site-centered management innovation is an organization that helps managers to quickly solve the problems faced by field management personnel by switching from manager-centered management method to on-site management personnel-oriented management. Find out the waste factors of the work and improve the process and set the process standards according to the customer's needs. Before working on the site, an employee should know exactly the process standard of what I will do, and frequently inspect the raw materials to make sure they meet the specifications. After the self-inspection is carried out, the standard is reviewed. If there is no abnormality, the cross-validation is carried out by the method which is carried over to the next step. The results of this study can be used to enhance the competitiveness of manufacturing companies. New management innovation techniques are required to adapt to the rapidly changing international business environment, and this study has implications for this research.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.6
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• pp.116-126
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• 2008

This paper describes the Dual-band WLAN transmitter with 2.4[GHz], 5[GHz]. Dual-band WLAN transmitter was designed at 2.4[GHz] and 5[GHz]. The Dual-band WLAN transmitter has a amplifier which operate at 2.4[GHz] and 5[GHz] frequency and two VCO(Voltage Controlled Oscillator) or VCO has a wide scope of frequency. these problem cause a size and a power consumption, The Dual-band WLAN transmitter module was proposed to solve these. the transmitter was designed to get output signals of IEEE 802.11a's 5.8[GHz] band signal using frequency multiplication way or to act a amplifier about the 2.4[GHz] band signal of IEEE 802.11b/g, according to inputed frequency and bias voltage that a eve using single transmission block. The output spectrum get the improved specification of ACPR of 4[dB], 6[dB], 16[dB] at +11[MHz], +20[MHz], +30[MHz] offset of center frequency compared to no linearization, was satisfied to transmit spectrum mask of IEEE 802.11a wireless Lan.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.12
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• pp.1679-1686
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• 2019

The main purpose of this research is to propose an approach for solving the packet loss problem by quickly adapting to topology change when nodes move in RPL-based IoT environment. In order to enhance mobility, every node is aware of the mobility of its neighbor nodes and quantifies the mobility level based on the number of control messages and all received packets. According to the mobility level, the DIO timer is changed. The proposed approach allows nodes to change their DIO timers according to their mobility levels to adapt topology changes and update paths to the sink. The performance of the proposed approach is evaluated using a Contiki-based Cooja simulator in various moving speeds. The simulation results show that the proposed approach copes with mobility scenarios better than the standard RPL by ascertaining that the packet delivery ratio is improved by 31.03%.

• Journal of KIISE:Information Networking
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• v.33 no.1
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• pp.38-48
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• 2006

For extending of hot-spot of WLAN, (2) proposes internetworking scheme between wireless LAN (WLAN) and mobile ad-hoc network (MANET), which employ the same layer-2 protocol with different mode. Compared to internetworking schemes between UMTS (Universal Mobile Telecommunications Systems) and WLAN (3-4), the scheme from (2) has relatively low overhead and latencies because WLAN and MANET are physically and logically similar to each other. However, the mode switching algorithm proposed in r2] for internetworking between WLAN and MANET only considers signal strength and determines handoff, and mobile nodes following a zigzag course in pollution area may perform handoff at short intervals. Furthermore, (2) employs mobile IPv6 (MIPv6) at base, which brings still high delay on handoff and overhead due to signal message exchange. In this paper, we present optimized internetworking scheme between WLAN and MANET, modified from (2). To settle ping-pong handoff from (2), we propose adaptive mode switching algorithm. HMIPv6 is employed for IP connectivity and mobility service in WLAN, which solves some shortcomings, such as high handoff overhead and vulnerable security. For routing in MANET, OLSR is employed, which is a proactive Protocol and has optimally reduced signal broadcasting overhead. OLSR operates with current P protocol compatibly with no change or modification. The proposed internetworking scheme based on adaptive mode switching algorithm shows better performance than scheme from (2).

• The KIPS Transactions:PartC
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• v.17C no.3
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• pp.271-280
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• 2010

For the next generation mobile communication system, diverse wireless network techniques such as beyond 3G LTE, WiMAX/WiBro, and next generation WLAN etc. are proceeding to the form integrated into the All-IP core network. According to this development, Beyond 3G integrated into heterogeneous wireless access technologies must support the vertical handover and network to be used of several radio networks. However, unified management of each network is demanded since it is individually serviced. Therefore, in order to solve this problem this study is introducing the theory of Common Radio Resource Management (CRRM) based on Generic Link Layer (GLL). This study designs the structure and functions to support the vertical handover and propose the vertical handover algorithm of which policy-based and MCDM are composed between LTE and WLAN systems using GLL. Finally, simulation results are presented to show the improved performance over the data throughput, handover success rate, the system service cost and handover attempt number.

• Proceedings of the Korea Technology Innovation Society Conference
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• 1998.05a
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• pp.10-10
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• 1998

생명공학의 혁신적 발명성을 매우 잘 보여주는 성공사례의 하나가 사람락토페린을 함유한 형질전환 젖소의 개발이다. 우유의 모유화를 내걸고 있는 본 연구는 국내·외에 막대한 잠재시장 규모가 예상되고 있다. 그러나 생명공학 제품은 ‘생물 재해(Bio Hazard)’에 대한 우려와 윤리문제를 제기할 수 있기 때문에 대중인식(Public Acceptance)에 대한 연구가 매우 중요한 의미를 가지는 것이다. 이러한 상황인식하에 사람락토페린을 함유한 유제품에 대한 소비자행태분석(Consumer Behavior Analysis)을 수행하게 되었다. 본 연구에 사용된 연구방법은 비시장가치평가법 중 임의가치평가법(CVM)을 사용하고 있다. 임의가치평가법은 선진국 특히 본 이론의 발상지인 미국에서 환경재기 가치를 측정하는 방법으로 사용되어 오고 있는데 이를 신상품 및 과학기술의 가치평가법으로 확대하여 연구하여온 필자의 일련의 연구중의 한 시도이다. 좋은 CVM 연구를 수행하기 위해서는 CVM이 요구하는 가치평가방법에 맞추어 설문서가 구성되고 분석되는 일이 무엇보다도 중요한 일이다. 본 연구에서는 CVM의 연구방법에 맞추어 사람락토페린 강화우유에 대한 소비자지불의향(Consumer Willingness to Pay) 조사와 더불어 사람락토페린 강화우유에다가 DHA, 칼슘 등 새로운 기능성 물질을 추가하여 더욱 좋은 기능을 첨가한 경우의 구입할 용의와 지불의향에 대한 조사를 수행하였다. 본 연구에서는 과학기술에 의해 탄생된 신상품에 대한 임의가치평가법의 적용이라는 새로운 시도의 연구라는점을 감안하여 본 연구를 바탕으로 더욱 새로운 문제제기와 추가적인 연구가 필요하다고 생각된다.적인 자세를 견지한다. 한편, 적응의 원리에 입각한 교육은 문화와 전통에 대한 피동적 전승을 넘어서 사회의 변화에 따라 교육체제와 내용을 바꾸는 등 적극적으로 변화에 대응하고, 이러한 변화를 주도할 인간육성에 힘을 기울이는 교육방식을 취한다. 시대적 변화의 소용돌이 속에서 교육은 이제 기왕의 많은 교육적 신화들을 타파하고 뉴 밀레니엄을 준비해야할 기로에 서 있다. 현재의 변화를 슬기롭게 대처하고 미래의 변화에 능동적으로 적응하는 인간을 육성하기 위한 오늘날 교육의 사명은 우선 미래사회를 위한 교육정책의 방향을 수립하는 일이다. 교육정책은 국가의 교육방침으로서 현실 교육문제의 해결도 중요하지만 미래의 발전을 기약할 수 있는 장기적인 비젼과 목표 속에서 정립될 필요가 있다. 이러한 의도하에 본 연구는 21세기를 대비한 교육정책의 방향을 탐색하고 그에 따른 정책적 과제를 제시하는 데 그 목적이 있다. 이러한 목적하에 본고는 \circled1 과거 우리 나라의 교육정책을 반성적으로 회고하고, \circled2 미래사회에 대한 전망과 교육적 시사점을 분석하며, \circled3 마지막으로 21세기의 변화에 적응하기 위한 교육정책의 방향과 과제를 내용으로 제시하고자 한다.탄산염으로의 전환이 진행되고 있다. 이러한 배경으로부터 Uchida그룹에서 개발한 FeiCr/AVTi재료와 현재 분리판 재료로 사용증인 SUS 310, S SUS 316재료에 대해. 산화성 분위기의 5기압까지의 가압하에서, Li-K, Li-Na탄산염에 대하여 부 식거동을 검토한 결과, 가압하에서 내식성이 향상되는 것이 발견되었다. 이유로서는 가압하에서 용융탄산엽의 증가된 산화력으로 보다 치밀한 내식성 산화물 피막

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.47 no.5
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• pp.43-51
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• 2010

Attenuation coefficients of medical ultrasound not only reflect the pathological information of tissues scanned but also provide the quantitative information to compensate the decay of backscattered signals for other medical ultrasound parameters. Based on the frequency-selective attenuation property of human tissues, attenuation estimation methods in spectral domain have difficulties for real-time implementation due to the complexicity while estimation methods in time domain do not achieve the compensation for the diffraction effect effectively. In this paper, we propose the modified VSA method, which compensates the diffraction with reference phantom in time domain, using adaptive bandpass filters with decreasing center frequencies along depths. The adaptive bandpass filtering technique minimizes the distortion of relative echogenicity of wideband transmit pulses and maximizes the signal-to-noise ratio due to the random scattering, especially at deeper depths. Since the filtering center frequencies change according to the accumulated attenuation, the proposed algorithm improves estimation accuracy and precision comparing to the fixed filtering method. Computer simulation and experimental results using tissue-mimicking phantoms demonstrate that the distortion of relative echogenicity is decreased at deeper depths, and the accuracy of attenuation estimation is improved by 5.1% and the standard deviation is decreased by 46.9% for the entire scan depth.

• Journal of Agricultural Extension & Community Development
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• v.20 no.1
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• pp.71-103
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• 2013

The purpose of this study is the awareness about the experiences of immigrant women residing in rural areas of life in Korea. Immigrant women residing in Gyeonggi Province and Incheon was a self-reported survey. Data collected by utilizing the SAS(Statistical Analysis System), percentage, mean, standard deviation, frequency analysis, including descriptive statistics were used. Findings, more than half of the migrant women are satisfied with their lives, and showed a high level of satisfaction with the husband. Learning map awareness in the education of their children in the most difficult and the necessary support to the children the basic curriculum map, Children's education as a way to solve the problem of after-school and school education activated and was the language barrier. Hard life in Korea, the language is a problem, Place discrimination received was a public place. Adapt to Korean society, language communication, child education, community adjustment problems with the same level of help was most needed. Meetings or activities often involve religious organizations, their home country, and meeting friends. His native Koreans, when it is difficult to discuss in order. Based on the results of such, Korea and community well adapted to the social framework that can nurture children married immigrant women in rural areas communities and Korean society and institutional as well prepared, and In addition, the foundation will need to activate the program.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.4 s.95
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• pp.389-396
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• 2005

In this paper, we propose a pre-distortion method using the NLMS(Normalized Least Mean Square) algorithm to cope with hish PAPR(Peak to Average Power Ratio) problem in OFDM communication system. This proposed scheme estimates the distortion characteristics of HPA, and changes the characteristic against the distortion. Therefore, it can be shown that the adaptive characteristic of the NLMS pre-distorter is good to track the various nonlinear characteristic of HPA, even though HPA characteristic is changed by temperature variation or aging. From the performance analysis, SNR efficiency of NLMS pre-distorter is about $0.5\;\cal{dB}$ less than that of common numerical non-adaptive pre-distorter, when IBO(Input Back Off) is $0\;\cal{dB}$. However, the NLMS pre-distorter is better than the common numerical pre-distorter, because these two pre-distorters have similar performance in higher than $3\;\cal{dB}$ IBO, and the NLMS pre-distorter maintains the constant performance even though characteristic of HPA is changed.