• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.12 s.354
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• pp.15-22
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• 2006

In this paper, 1.8V 8-bit 500MSPS Low-power CMOS Digital-to-Analog Converter(DAC) for UWB(Ultra Wide Band) Communication Systeme is proposed. The architecture of the DAC is based on a current steering 6+2 full matrix type which has low glitch and high linearity. In order to achieve a high speed and good performance, a current cell with a high output impedance and wide swing output range is designed. Further a thermometer decoder with same delay time and low-power switching decoder for high efficiency performance are proposed. The proposed DAC was implemented with TSMC 0.18um 1-poly 6-metal N-well CMOS technology. The measured SFDR was 49dB when the output frequency was 50MHz at 500MS/s sampling frequency. The measured INL and DNL were 0.9LSB and 0.3LSB respectively. The DAC power dissipation was 20mW and the effective chip area was $0.63mm^2$.

• Journal of Korean Society of Transportation
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• v.17 no.2
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• pp.55-68
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• 1999

Many ITS services require map databases in digital form to meet desired needs. Due to the dynamic nature of ITS and the sheer diversity of applications, the design and development of spatial databases to meet those needs pose a major challenge to both the public and private sectors. This challenge is further complicated by the necessity to transfer locationally referenced information between different kinds of databases and spatial data handling systems so that ITS products will work seamlessly across the region and nation. The Purpose of this paper is to develop the framework-models commonly to reference locations in the various applications and systems-the ITS Map Datum and LRS(Location Referencing System). The ITS Map Datum consists of the around control points which are the prime intersections (nodes) of the nationwide road network In this study, the major points have been determined along wish link-node modeling procedure. LRS, defined as a system for determining the position (location) of an entity relative to other entities or to some external frame of reference, has also been set up using CSOM type method. The method has been implemented using ArcView GIS software over the Kangnam and Seocho districts in the city of Seoul, showing that the implemented LRS scheme can be used successfully elsewhere. With the proper advent of the K.ITS architecture and services, the procedure can be used to improve the data sharing and to inter operate among systems, enhancing the efficiency both in terms of money and time.

• Journal of the Korean Society for Marine Environment & Energy
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• v.8 no.1
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• pp.46-52
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• 2005

A marine environmental information system (MEIS) useful for optimal route planning of ships running in the ocean was developed. Utilizing the simulated marine environmental data produced by the European Center for Medium-Range Weather Forecasts based on global environmental data observed by satellites, the real-time forecast and long-term statistics of marine environments around planned and probable ship routes are provided. The MEIS consists of a land-based data acquisition and analysis system(MEIS-Center) and a onboard information display system(MEIS-Ship) for graphic description of marine information and optimal route planning of ships. Also, it uses of satellite communication system for data transfer. The marine environmental components of winds, waves, air pressures and storms are provided, in which winds are described by speed and direction and waves are expressed in terms of height, direction and period for both of wind waves and swells. The real-time information is characterized by 0.5° resolution, 10 day forecast in 6 hour interval and daily update. The statistic information of monthly average and maximum value expected for a return period is featured by 1.5° resolution and based on 15 year database. The MEIS-Ship include an editing tool for route simulation and the forecasting and statistic information on planned routes can be displayed in graph or table. The MEIS enables for navigators to design an optimal navigational route that minimizes probable risk and operational cost.

• Journal of the Korean Association of Geographic Information Studies
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• v.20 no.2
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• pp.32-46
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• 2017

Recent rapid urban expansion and crowding of various industrial facilities has affected the features of a significant part of downtown area, resulting in areas having buildings with a wide range of height and the foothills. To compute a velocity pressure exposure coefficient, namely the design wind speed factor, this study defines ground surface roughness by utilizing concentration analysis for the height of each building. After obtaining spatial data by extracting a building layer from digital maps, the study area was partitioned for the concentration analysis and to allow investigation of the frequency distribution of building heights. Concentration analysis by building height was determined with the Variation-to-Means Ratio (VMR) and Poisson distribution analysis using a buildings distribution chart, with statistical significance determined using Chi-square verification. Applying geographic information systems (GIS) with the architectural information made it possible to estimate a velocity pressure exposure coefficient factor more quantitatively and objectively, by including geographic features, as compared to current methods. Thus, this method is expected to eliminate inaccuracies that arise when building designers calculate the velocity pressure exposure coefficient in subjective way, and to help increase the wind resistance of buildings in a more logical and cost-effective way.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.4
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• pp.1-9
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• 2009

In this paper, a small area 12-bit 300MSPS CMOS Digital-to-Analog Converter(DAC) is proposed for display systems. The architecture of the DAC is based on a current steering 6+6 segmented type, which reduces non-linearity error and other secondary effects. In order to improve the linearity and glitch noise, an analog current cell using monitoring bias circuit is designed. For the purpose of reducing chip area and power dissipation, furthermore, a noble self-clocked switching logic is proposed. To verify the performance, it is fabricated with $0.13{\mu}m$ thick-gate 1-poly 6-metal N-well Samsung CMOS technology. The effective chip area is $0.26mm^2$ ($510{\mu}m{\times}510{\mu}m$) with 100mW power consumption. The measured INL (Integrated Non Linearity) and DNL (Differential Non Linearity) are within ${\pm}3LSB$ and ${\pm}1LSB$, respectively. The measured SFDR is about 70dB, when the input frequency is 15MHz at 300MHz clock frequency.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.11
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• pp.86-94
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• 2012

In this paper we propose a hardware architecture of high-speed CGH (computer generated hologram) generation processor, which particularly reduces the number of memory access times to avoid the bottle-neck in the memory access operation. For this, we use three main schemes. The first is pixel-by-pixel calculation rather than light source-by-source calculation. The second is parallel calculation scheme extracted by modifying the previous recursive calculation scheme. The last one is a fully pipelined calculation scheme and exactly structured timing scheduling by adjusting the hardware. The proposed hardware is structured to calculate a row of a CGH in parallel and each hologram pixel in a row is calculated independently. It consists of input interface, initial parameter calculator, hologram pixel calculators, line buffer, and memory controller. The implemented hardware to calculate a row of a $1,920{\times}1,080$ CGH in parallel uses 168,960 LUTs, 153,944 registers, and 19,212 DSP blocks in an Altera FPGA environment. It can stably operate at 198MHz. Because of the three schemes, the time to access the external memory is reduced to about 1/20,000 of the previous ones at the same calculation speed.

• World Technopolis Review
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• v.8 no.2
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• pp.74-81
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• 2019

Cities will soon host two third of the population worldwide, and already today 80% of the world energy is used in the 20 largest cities. Urban areas create 80% of the greenhouse gas emission, so we should take care that urban areas are smart and sustainable as implementations have especially here the greatest impact. Smart Cities (SC) or Smart Sustainable Cities (SSC) are the actual concepts that describe methodologies how cities can handle the high density of citizens, efficiency of energy use, better quality of life indicators, high attractiveness for foreign investments, high attractiveness for people from abroad and many other critical improvements in a shifting environment. But if we talk about Entrepreneurship Ecosystem and Innovation, we do not see a lot of literature covering this topic within those SC/SSC concepts. It seems that 'Smart' implies that all is embedded, or isn't it properly covered as brick stone of SC/SSC concepts, as they are handled in another 'responsibility silo', meaning that the policy implementation of a Science and Technology Park (STP) is handled in another governing body than SC/SSC developments. If this is true, we will obviously miss a lot of synergy effects and economies of scale effects. Effects that we could have in case we stop the siloed approaches of STPs by following a more holistic concept of a Smart Sustainable City, covering also a continuous flow of innovation into the city, without necessarily always depend on large corporate SSC solutions. We try to argue that every SSC should integrate SP/STP concepts or better their features and services into their methodology. The very limited interconnectivity between these concepts within the governance models limits opportunities and performance in both systems. Redesigning the architecture of the governance models and accepting that we have to design a system-of-systems would support the possible technology flow for smart city technologies, it could support testbed functionalities and the public-private partnership approach with embedded business models. The challenge is of course in complex governance and integration, as we often face siloed approaches. But real SSC are smart as they are connecting all those unconnected siloes of stakeholders and technologies that are not yet interoperable. We should not necessarily follow anymore old greenfield approaches neither in SSCs nor in SP and STP concepts from the '80s that don't fit anymore, being replaced by holistic sustainability concepts that we have to implement in any new or revised SSC concepts. There are new demands for each SP/STP being in or close to an SC/SCC as they have a continuous demand for feeding the technology base and the application layer and should also act as testbeds. In our understanding, a big part of STP inputs and outputs are still needed, but in a revised and extended format. We know that most of the SC/STP studies claim the impact is still far from understood and often debated, therefore we must transform the concepts where SC/STPs are not own 'cities', but where they act as technology source and testbed for industry and new SSC business models, being part of the SC/STP concept and governance from the beginning.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.38 no.7
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• pp.455-463
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• 2001

In this Paper, an approximate processing method is proposed and tested. The proposed method uses variable CSD (VCSD) coefficients which approximate filter stopband attenuation by controlling the precision of the CSD coefficient sets. A decimation filter for Audio Codec '97 specifications has been designed having processor architecture that consists of program/data memory, arithmetic unit, energy/level decision, and sinc filter blocks, and fabricated with 0.6${\mu}{\textrm}{m}$ CMOS sea-of-gate technology. For the combined two halfband FIR filters in decimation filter, the number of addition operations were reduced to 63.5%, 35.7%, and 13.9%, compared to worst-case which is not an adaptive one. Experimental results show that the total power reduction rate of the filter is varying from 3.8 % to 9.0 % with respect to worst-case. The proposed approximate processing method using variable CSD coefficients is readily applicable to various kinds of filters and suitable, especially, for the speech and audio applications, like oversampling ADCs and DACs, filter banks, voice/audio codecs, etc.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.13 no.3
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• pp.184-196
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• 2020

In this paper, a single-bit 2nd-order delta-sigma modulator with the architecture of cascaded-of-integrator feedforward (CIFF) is proposed for precision measurement of current flowing through a secondary cell battery in a battery management system (BMS). The proposed modulator implements two switched capacitor integrators and a single-bit comparator with peripheral circuits such as a non-overlapping clock generator and a bias circuit. The proposed structure is designed to be applied to low-side current sensing method with low common mode input voltage. Using the low-side current measurement method has the advantage of reducing the burden on the circuit design. In addition, the ±30mV input voltage is resolved by the ADC with 15-bit resolution, eliminating the need for an additional programmable gain amplifier (PGA). The proposed a single-bit 2nd-order delta-sigma modulator has been implemented in a 350-nm CMOS process. It achieves 95.46-dB signal-to-noise-and-distortion ratio (SNDR), 96.01-dB spurious-free dynamic range (SFDR), and 15.56-bit effective-number-of-bits (ENOB) with an oversampling ratio (OSR) of 400 for 5-kHz bandwidth. The area and power consumption of the delta-sigma modulator are 670×490 ㎛2 and 414 ㎼, respectively.

• Journal of Intelligence and Information Systems
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• v.20 no.1
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• pp.149-161
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• 2014

The export of domestic public services to overseas markets contains many potential obstacles, stemming from different export procedures, the target services, and socio-economic environments. In order to alleviate these problems, the business incubation platform as an open business ecosystem can be a powerful instrument to support the decisions taken by participants and stakeholders. In this paper, we propose an ontology model and its implementation processes for the business incubation platform with an open and pervasive architecture to support public service exports. For the conceptual model of platform ontology, export case studies are used for requirements analysis. The conceptual model shows the basic structure, with vocabulary and its meaning, the relationship between ontologies, and key attributes. For the implementation and test of the ontology model, the logical structure is edited using Prot$\acute{e}$g$\acute{e}$ editor. The core engine of the business incubation platform is the simulator module, where the various contexts of export businesses should be captured, defined, and shared with other modules through ontologies. It is well-known that an ontology, with which concepts and their relationships are represented using a shared vocabulary, is an efficient and effective tool for organizing meta-information to develop structural frameworks in a particular domain. The proposed model consists of five ontologies derived from a requirements survey of major stakeholders and their operational scenarios: service, requirements, environment, enterprise, and county. The service ontology contains several components that can find and categorize public services through a case analysis of the public service export. Key attributes of the service ontology are composed of categories including objective, requirements, activity, and service. The objective category, which has sub-attributes including operational body (organization) and user, acts as a reference to search and classify public services. The requirements category relates to the functional needs at a particular phase of system (service) design or operation. Sub-attributes of requirements are user, application, platform, architecture, and social overhead. The activity category represents business processes during the operation and maintenance phase. The activity category also has sub-attributes including facility, software, and project unit. The service category, with sub-attributes such as target, time, and place, acts as a reference to sort and classify the public services. The requirements ontology is derived from the basic and common components of public services and target countries. The key attributes of the requirements ontology are business, technology, and constraints. Business requirements represent the needs of processes and activities for public service export; technology represents the technological requirements for the operation of public services; and constraints represent the business law, regulations, or cultural characteristics of the target country. The environment ontology is derived from case studies of target countries for public service operation. Key attributes of the environment ontology are user, requirements, and activity. A user includes stakeholders in public services, from citizens to operators and managers; the requirements attribute represents the managerial and physical needs during operation; the activity attribute represents business processes in detail. The enterprise ontology is introduced from a previous study, and its attributes are activity, organization, strategy, marketing, and time. The country ontology is derived from the demographic and geopolitical analysis of the target country, and its key attributes are economy, social infrastructure, law, regulation, customs, population, location, and development strategies. The priority list for target services for a certain country and/or the priority list for target countries for a certain public services are generated by a matching algorithm. These lists are used as input seeds to simulate the consortium partners, and government's policies and programs. In the simulation, the environmental differences between Korea and the target country can be customized through a gap analysis and work-flow optimization process. When the process gap between Korea and the target country is too large for a single corporation to cover, a consortium is considered an alternative choice, and various alternatives are derived from the capability index of enterprises. For financial packages, a mix of various foreign aid funds can be simulated during this stage. It is expected that the proposed ontology model and the business incubation platform can be used by various participants in the public service export market. It could be especially beneficial to small and medium businesses that have relatively fewer resources and experience with public service export. We also expect that the open and pervasive service architecture in a digital business ecosystem will help stakeholders find new opportunities through information sharing and collaboration on business processes.