• 전자공학회논문지SC
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• 제49권1호
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• pp.57-63
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• 2012

본 논문에서는 크로스 레귤레이션을 방지하기 위한 TM 방식 SIDO DC-DC 벅 컨버터의 스위치 트랜지스터 크기 계산 기법을 제안하였다. TM 방식 SIDO DC-DC 벅 컨버터는 DCM 동작으로 인한 인덕터 전류의 높은 첨두치와 추가된 스위치의 저항성분으로 인한 전압강하 때문에 크로스 레귤레이션이 일어날 수 있다. 이 문제점을 해결하기 위해 스위치 트랜지스터의 저항성분을 고려하여 스위치 트랜지스터의 크기를 계산하였고, 계산을 간단히 하기 위해 시간의 함수인 인덕터의 전류를 평균부하 전류로 대체하였다. 제안한 기법을 이용하여 2.8 V와 1.8 V의 독립된 두 출력을 내는 카메라 모듈용 SIDO DC-DC 벅 컨버터를 설계하였고, $0.35{\mu}m$ CMOS 공정을 사용하여 제작하였다. 제작된 컨버터는 스위칭 주파수 1 MHz와 부하전류 200 mA 에서 80.7%의 효율을 보였다.

• 한국정보시스템학회지:정보시스템연구
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• 제20권2호
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• pp.135-154
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• 2011

The Sido.Saeol system, a local government information system cost too much for having been designed and developed during last four years but the effectiveness of this system is still open to doubt. Also maintenance cost is still too high and become increasing year by year. To find out the reasons and to suggest how to solve these problems, a service quality of an Sido Saeol system and the public servant's job satisfaction were investigated based on the Delone and McLean's updated IS success Model(2003). To investigate of the effectiveness of the Sido Saeol system, 8 variables are analyzed to test 3 main hypothesis. After all the analysis, we found that Sido.Saeol systems have many aspects to be improved for system use and job satisfaction and have to be revise in the aspects of system qualities.

• The Journal of Asian Finance, Economics and Business
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• 제7권11호
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• pp.885-892
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• 2020

The purpose of this study was to determine the social engagement network in Sido Muncul's CSR, the partnership program with farmers, and how the implementation of corporate social entrepreneurship in the program is carried out. The research design uses qualitative methods with a grounded theory approach that tests the validity and reliability of the data using triangulation of data sources and methods, namely, data obtained through documentation and the results of surveys and interviews to more than one observation unit. Data was obtained from surveys and interviews with Sido Muncul's Public Relations and CSR Division, as well as partner farmers. The results of this study indicate that the social engagement network in Sido Muncul's partnership program is related to the role of farmer groups, farmer cooperatives, government, NGOs, universities, and private companies as facilitators and control functions, thus creating mutually beneficial relationships with one another. The process of implementing corporate social entrepreneurship in Sido Muncul's CSR for the partnership program with farmers consists of nine stages: problem identification, coordination with related parties, allocation of resources and commitments, collaboration with NGOs, local entrepreneurs and government, social innovation and the creation of new businesses, documentation of activities, reporting, monitoring and evaluation, as well as publications.

• 전기전자학회논문지
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• 제20권4호
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• pp.432-434
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• 2016

기존 SIDO(Single Inductor Dual Output) boost converter에서는 전력 사용량의 변화에 맞게 부하에 전하를 공급하는 시간을 바꾸게 된다. 이 때 boost converter의 스위칭 주파수가 변해야 할 정도로 어느 한 부하의 전력 사용량이 크게 바뀔 경우, 나머지 부하에 전하를 공급하는 시간도 바뀌게 된다. 이로 인해 크로스 레귤레이션이 일어난다. 따라서 본 논문에서는 어느 한 부하의 전력 사용량의 변화로 스위칭 주파수가 정수 비로 바뀔 때 나머지 부하에 전하를 공급하는 시간도 같은 정수 비로 변화 시킨다. 이 방법을 전하 복사기법(charge copy)이라 하며 이 효과로 인하여 크로스 레귤레이션이 감소한다. 제안하는 방법의 시뮬레이션 결과로 크로스 레귤레이션이 기존의 방법보다 10.42mV/A 만큼 감소하고, 복원 시간은 39.118us 만큼 작아지는 결과를 보였다.

• Journal of Power Electronics
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• 제16권5호
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• pp.1802-1812
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• 2016

Cross regulation is a key technical issue of single-inductor multiple-output (SIMO) DC-DC converters. This paper investigates the cross regulation in single-inductor dual-output (SIDO) Buck converters with continuous conduction mode (CCM) operation. The expressions of the DC voltage gain, control to the output transfer function, cross regulation transfer function, cross coupled transfer function and impedance transfer function of the converter are presented by the time averaging equivalent circuit approach. A small signal model of a SIDO CCM Buck converter is built to analyze this cross regulation. The laws of cross regulation with respect to various load conditions are investigated. Simulation and experiment results verify the theoretical analysis. This study will be helpful for converter design to reduce the cross regulation. In addition, a control strategy to reduce cross regulation is performed.

• 이베로아메리카
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• 제12권1호
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• pp.323-347
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• 2010

La latinoamericanización de la inmigración a España ha comenzado a partir de principios del nuevo milenio. Ahora los latinoamericanos superan a los inmigrantes de Marruecos, que han sido más numerosos. El número de inmigrantes latinoamericanos en España es de más de 1,700,000, cifra que corresponde al 34% del total de los inmigrantes. Como es sabido, los latinoamericanos vienen a España con el fin de buscar la oportunidad de una vida mejor. La economía española ha ido bien y la condición del mercado laboral ha sido favorable a los inmigrantes de América del Sur por lo que su mayoría puede consequir el empleo y mandar el dinero a sus queridos familiares. Por otra parte, la expansión de la comunidad latinoamericana en España se debe a la hispanidad que une a América con España. Como ellos comparten misma creencia y mismo idioma con los españoles, a la vista de los españoles, son considerados 'más seguros' que los inmigrantes de otra nacionalidad cuando se establecen y se integran a la sociedad española. De este modo, la inmigración latinoamericana presente en España debe ser percibido tanto en la dimensión institucional como en el contexto histórico-cultural.

• 전기전자학회논문지
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• 제18권2호
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• pp.220-227
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• 2014

이 논문은 Dead-time을 갖는 톱니파 발생기를 이용하여 공통모드와 차동모드 피드백 루프를 구현한 Single-Inductor Dual-Output DC-DC Converter 설계에 관한 내용을 제시하고 있다. 제어회로에는 공통모드와 차동모드 피드백 루프를 Dead-time을 갖는 톱니파 발생기를 이용하여 동시에 사용하였다. 차동모드 피드백 루프에서 duty를 생성하기 위해서 전류 분배기 회로를 사용하여 공통모드 피드백에 의한 duty에 따라 dead-time이 유동적으로 변하는 톱니파형을 만드는 회로인 Dead-time을 갖는 톱니파 발생기를 추가하여 차동모드 피드백 회로를 구성하였다. 0.35um 공정을 사용하여 설계한 SIDO DC-DC Converter는 2.5V 입력으로부터 2.8V와 4.2V의 전압을 출력하며 최대 전력변환 효율은 95%이다. 출력간의 Cross regulation은 출력전류가 2배씩 증가할 경우 Boost1과 Boost2의 출력전압은 각각 3.57%, 4% 수준을 보이고 있다.

• Journal of Power Electronics
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• 제17권6호
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• pp.1433-1444
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• 2017

A family of non-isolated DC-DC three-port converters (TPCs) that allows for a more flexible power flow among a renewable energy source, an energy storage device and a current-reversible DC bus is introduced. Most of the reported non-isolated topologies in this area consider only a power consuming load. However, for applications such as hybrid-electric vehicle braking systems and DC microgrids, the load power generating capability should also be considered. The proposed three-port family consists of one unidirectional port and two bi-directional ports. Hence, they are well-suited for photovoltaic (PV)-battery-DC bus systems from the power flow viewpoint. Three-port converters are derived by combining different commonly known power converters in an integrated manner while considering the voltage polarity, voltage levels among the ports and the overall voltage conversion ratio. The derived converter topologies are able to allow for seven different modes of operation among the sources and load. A three-port converter which integrates a boost converter with a buck converter is used as a design example. Extensions of these topologies by combining the soft-switching technique with the proposed design example are also presented. Experiment results are given to verify the proposed three-port converter family and its analysis.

• 비교문화연구
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• 제34권
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• pp.285-306
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• 2014

La historia sobre la ${\acute{e}}poca$ de la independencia y la $formac{\acute{o}}n$ de las naciones latinoamericanas enfatiza sobre todo los roles de los hombres y $espor\acute{a}dicamente$ de las mujeres. Se han considerado directrices las acciones de algunos criollos de esa epoca como $Sim{\acute{o}}n$ Bolivar y San Martín. La historiografía masculina-$c{\acute{e}}ntrica$ $est{\acute{a}}$ ignorando y marginando las luchas y los sacrificios de las mujeres que participaron en la independencia y la $formac{\acute{o}}n$ de las naciones. Por tanto, es preciso realizar una crítica a los procesos que han mantenido la tendencia machista, uno de ellos es porque no se han desatendido concepciones y cosmovisiones sobre el $g{\acute{e}}nero$. En fin, esta tendencia es porque no se ha superado la herencia colonial de manera crítica. En este contexto, este artículo intenta investigar los cambios sobre los puntos de vista y la manera de ver a las mujeres y sus actividades durante la ${\acute{e}}poca$ de la independencia. Puesto que las mujeres han sido consideradas como objetos que ocupan un espacio secundario en $comparaci{\acute{o}}n$ a los roles de los criollos. Este estudio pretende configurar nuevos puntos de vista para reestructurar nuestro enfoque tradicional sobre la independencia y las formaciones de las naciones latinoamericanas para poner en evidencia los roles de las mujeres en la historia.

• 이베로아메리카
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• 제12권1호
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• pp.55-86
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• 2010

Después de la década 1990, la soja ha sido un agro-producto más importante en Paraguay. Pero la soja ha convertido el campo rural en la zona de la producción, es decir, la zona de sojización, para la exportación. Por otro lado, el campo rural se ha deteriorado por el aumento de la extensión del cultivo sojal. Los cultivos se extienden a lo largo de cientos de kilómetrios y afectan zonas muy cercanas a comunidades, colonias y otros asentamientos campesionos e indígenas, incluyendo escuelas, hogares, charcas familiares y comunitarias. Los sojeros utilizaron los agrotóxicos que contaminaron la tierra, agua y alimentos. Aunque los campesinos no quieren vender sus tierras, no ven otras alternativas ante los graves problemas que conllevan las masivas fumigaciones. Ellos venden sus lotes y migraron a ciudades. Se pierde la soberanía territorial, pues las tierras pasan a manos extranjeras, y la soberanía alimentaria, porque se desplaza la diversificación y los cultivos de subsistencia, expulsando a los campesions hacia las ciudades. Ante el agravamiento de la situación causado por el incremento del cultivo de la soja, los campesinos empezaron a resistir, es decir, desarrollar 'la guerra de la soja' contra los sojeros y el gobierno paraguayo que no tenia refuerzos de resolver los problemas. Los campesinos formaron coordinadoras por la defensa de sus tierras y de su modo de vida contra los sojeros. Las luchas y movilizaciones reclaman no sólo un nuevo tipo de reforma agraria sino también la defensa de la soberanía económica, alimentaria y territorial, el derecho a producir con la propia semilla y a desarrollar técnicas agrícolas adecuadas de acuerdo con la economía campesina y el equilibrio del medio ambiente, el desarrollo de formas sociales de producción y la democratización en el medio rural.