• Journal of IKEEE
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• v.22 no.4
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• pp.1025-1030
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• 2018

The proposed modulator is designed by utilizing a conventional structure employing time division technique to realize the 4th order delta-sigma modulator using one op-amp. In order to reduce the influence of KT/C noise, the capacitance in the first and second integrators reused was chosen to be 20pF and capacitance of third and fourth integrators was designed to be 1pF. The stage variable technique in the low power reconfigurable op-amp was used to solve the stability issue due to different capacitance loads for the reduction of KT/C noise. This technique enabled the proposed modulator to reduce the power consumption of 15% with respect to the conventional one. The proposed modulator was fabricated with 0.18um CMOS N-well 1 poly 6 metal process and consumes 305uW at supply voltage of 1.8V. The measurement results demonstrated that SNDR, ENOB, DR, FoM(Walden), and FoM(Schreier) were 66.3 dB, 10.6 bits, 83 dB, 98 pJ/step, and 142.8 dB at the sampling frequency of 256kHz, oversampling ratio of 128, clock frequency of 1.024 MHz, and input frequency of 250 Hz, respectively.

• Journal of IKEEE
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• v.22 no.4
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• pp.1006-1011
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• 2018

This paper proposes a three level buck converter utilizing multi-bit flying capacitor voltage control. The conventional three-level buck converter can not control the flying capacitor voltage, so that the operation is unstable or the circuit for controlling the flying capacitor voltage can not be applied to the PWM mode. Also when the load current is increased, an error occurs in the inductor voltage. The proposed structure can control the flying capacitor voltage in PWM mode by using differential difference amplifier and common mode feedback circuit. In addition, this paper proposes a 3bit flying capacitor voltage control circuit to optimize the operation of the three level buck converter depending on the load current, and a triangular wave generation circuit using the schmitt trigger circuit. The proposed 3-level buck converter is designed in $0.18{\mu}m$ CMOS process and has an input voltage range of 2.7V~3.6V and an output voltage range of 0.7V~2.4V. The operating frequency is 2MHz, the load current range is 30mA to 500mA, and the output voltage ripple is measured up to 32.5mV. The measurement results show a maximum power conversion efficiency of 85% at a load current of 130 mA.

• Journal of IKEEE
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• v.22 no.4
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• pp.1012-1018
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• 2018

In this paper, CMOS SAR (Successive Approximation Register) A/D converter with 1.8V supply voltage is designed for IoT sensor processing. This paper proposes design of a 12-bit SAR A/D converter with two A / D converters in parallel to improve the sampling rate. A/D converter1 of the two A/D converters determines all the 12-bit bits, and another A/D converter2 uses the upper six bits of the other A/D converters to minimize power consumption and switching energy. Since the second A/D converter2 does not determine the upper 6 bits, the control circuits and SAR Logic are not needed and the area is minimized. In addition, the switching energy increases as the large capacitor capacity and the large voltage change in the C-DAC, and the second A/D converter does not determine the upper 6 bits, thereby reducing the switching energy. It is also possible to reduce the process variation in the C-DAC by proposed structure by the split capacitor capacity in the C-DAC equals the unit capacitor capacity. The proposed SAR A/D converter was designed using 0.18um CMOS process, and the supply voltage of 1.8V, the conversion speed of 10MS/s, and the Effective Number of Bit (ENOB) of 10.2 bits were measured. The area of core block is $600{\times}900um^2$, the total power consumption is $79.58{\mu}W$, and the FOM (Figure of Merit) is 6.716fJ / step.

• The Korean Journal of Archival Studies
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• no.30
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• pp.89-123
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• 2011

Archival materials in film archives is a memories and archival documents of human which is generated from cultural activities of human being, and provided long-term relevant information. However, it is different general public audio-visual records because main purpose of representing culture to create the contents of private sector rather than evidence of the factual information of public service activities. Therefore, should determine the description principle and rule in order to reflect specific physical, intellectual characteristics. So as to control the description, that is need in the textual standards to base the specific purposes and rules thus analyzed the international description standards as Dublin Core, ISAD(G), FIAF Cataloguing Rules For Film Archives. As a result, more effectively to describe archival materials in film archives required significant modifications in the organizations of the areas and the elements. This study argues that first, to divide existence the concept and the reality (work/item) of archival materials in film archives. Second, to need understanding and indicating their content, context, structure. Third, to establish of the areas and the elements including a characteristic of it. The final suggestion organizes separately to 6th and 8th areas, 22th and 25th elements in two parts. This conclusion does not prepare to refer the status and/or policy of a particular film arhicve, can be set accordingly to a specific elements or sub-elements by the film archives.

• The Korean Journal of Archival Studies
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• no.36
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• pp.233-269
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• 2013

This study aims to explore practicable and sustainable strategies for locality documentation through networking, linking, and recontextualization of records in digital environments. It applies the 'spanDoc(SPAace-based Networked Documentation) Model to document Donghae-Nambu Railway areas placed in Busan Metropolitan City tentatively. Considering that mobility and openness are the main characteristics of Busan, railway areas and their stations can be proper places for representing such localities of the city. Moreover, there can be much experiences and memories of residents surrounding those areas, because Donghae-Nambu Railway has been used as short distance transportation facilities across the inner city of Busan since 1930's. This study tries to implement the documentation strategy for the selected space, following the procedures of the spanDoc Model. Firstly, this study develops the structure of the subjects through investigating the related information sources and archives from various collecting institutions. Secondly, it carries out records surveys to identify the essential records types for documenting the Donghae-Nambu Railway areas. Thirdly, it describes the subjects and sub-subjects, and the entries of places, people and subjects for adding to the dictionaries. Finally, it links many entities such as subjects, records, and dictionary, and builds the databases regarding the inter-links and systematic accumulation of the outputs of each step.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.7
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• pp.512-519
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• 2019

This study examined the components of we-ness perceived by elementary school teachers. The results of this research can be used as a new indicator based on the essential relationship of Korea to explain and improve the teacher culture and organizational culture of school. The subjects were 206 elementary school teachers. The data were analyzed using correlation, ANOVA, and exploratory factor analyses with SPSS 23, and confirmatory factor analysis with Mplus 7.1. The results of this study are as follows. First, 'psychological wellbeing', 'caring relationship', 'ethical legitimacy', and 'sharing time' were derived as the factors of early childhood teachers' perception of we-ness. In addition, considering that we-ness can be spread not only to individual relations, but also to the class, and to the same organization as a school, it can be used to form a school culture based on Korean culture and suggest a teaching culture. On the other hand, this study examined elementary school teachers; hence, the results cannot be applied to all teachers. In addition, this study was a quantitative study exploring the sub-factors through statistical analysis. The results of the quantitative research should be elaborated through interviews with school members, and follow - up studies should be conducted through case studies.

• Journal of the Korea Convergence Society
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• v.10 no.5
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• pp.229-238
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• 2019

The purpose of this study is to understand in depth the gambling experiences of delinquent juveniles who have dropped out of school and analyze the content and meaning of gambling experiences. Thus, utilized a Giorgi's phenomenological research method. Data was gathered through in-depth interviews, and the gambling experiences of six youths who are under juvenile law protective disposition were examined through a four-step analytic process. From the results, 6 parent components and 18 sub-components were derived. That is, "the temptation of close gambling", "trapped in the bridle of gambling", "deterioration of life", "damaged of non-official networks relationship", "corruption of existence" and "attempts to escape gambling" were appeared. These results are meaningful because they have allowed researchers to identify the essential meaning and experiential structure of delinquents juvenile' gambling experiences outside of school, which has not been studied thus far. Further, this study has empirical value as its framework includes a joint analysis in terms of welfare and gambling addiction and focuses on a precarious population-delinquent juveniles who have dropped out of school. The results provide a foundation from which practical implications and policy alternatives for the prevention and treatment of gambling problems in delinquent juveniles dropped out of school.

• The Mathematical Education
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• v.60 no.2
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• pp.173-190
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• 2021

Education for Sustainable Development is an imperative mean to achieve the sustainable development which is the key idea that meets the needs of both present and succeeding generations by reconciling environmental protection, social development and economic growth. This study addressed the following question. First, what is the overall structure of the ESD contents presented in the textbooks? Second, How are the sub-contents of ESD distributed in the textbooks? Lastly, How are the ESD contents connected to mathematics in the textbooks? For this purpose, the contents in the elemtentary mathematics textbooks from 1^st to 6^th grades were analyzed at both macro and micro levels through quantitative and qualitative research methods. As results, contents related to environmental, social, and economic dimensions were presented from the first grade. The contents were involved the mathematics content domains of Numbers and Operations, Data and Possibilities, and Patterns. However, the contents were presented intensively in middle and high grades, and environmental topics accounted for a high proportion. Among the activities related to ESD, many were focused on solving problems mathematically while some were presented to solve problems as well as to consider sustainability through the activities. Based on the results, the study aims to provide implications for the direction of mathematics education for sustainable development in elementary school.

• MISULJARYO - National Museum of Korea Art Journal
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• v.96
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• pp.181-208
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• 2019

This paper presents a new classification and code system on the Archives of the Government-general Museum of Joseon in the National Museum of Korea. Three points were noted that since the Museum belonged to the Government-general of Joseon, the classification system of the Archives should be established to comply with the Archives system of the Government-general of Joseon; based on the concept of the functional provenance, it is necessary to establish a classification system in accordance with the organization structure of the Government-general Museum of Joseon; a systematic and simple classification codes should be given based on the classification system to improve the convenience of searching and using the official document. The classification system and its code are proposed in the order of major function, medium function, small function, and detailed function. The major function of the Archives is 'A-Educational affairs', medium function 'Museum.' The small function may be divided into General affairs (01), Temple (02), Scenic Spot and Natural Monument (03), Historical Site (04), and Museum (05). The detailed function and detailed sub-functions are categorized by the various work assignments in each work units. I hope that this new classification system will make a contribution to organizing and utilizing the Archives of the Government-general Museum of Joseon in the National Museum of Korea.

• 한국노년학
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• v.36 no.4
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• pp.937-957
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• 2016

The purpose of this study was to understand deeply the meaning of training and counselling experiences of life planning counselors for the later life. This study analyzed the meaning of training and counselling experiences of counselors and tried to structure the meaning of their experiences. The qualitative research was conducted with 12 counselors who got the license after completing life planning training and do counselling. This study found 4 categories, 15 sub-categories and 50 concepts. These results analyzed are : 1) Motivation of participating in life planning counselor training for the later life ; 2) Training experience of life planning counselor for the later life ; 3) Counselling experience as a life planning counselor for the later life ; and 4) Way to improve capacity as a life planning counselor for the later life. According to these results, this study proposed practice and policy suggestions to improve training curriculum, working process and building capacity of counsellors. Lastly, this study stated the limitation and significance of the study and also suggested another proposal for a follow-up study.