• Asia pacific journal of information systems
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• v.20 no.3
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• pp.191-204
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• 2010

Recently, the CO2 emission and energy consumption have become critical global issues to decide the future of nations. Especially, the spread of IT products and the increased use of internet and web applications result in the energy consumption and CO2 emission of IT industry though information technologies drive global economic growth. EU, the United States, Japan and other developed countries are using IT related environmental regulations such as WEEE(Waste Electrical and Electronic Equipment), RoHS(Restriction of the use of Certain Hazardous Substance), REACH(Registration, Evaluation, Authorization and Restriction of CHemicals) and EuP(Energy using Product), and have established systematic green business/IT strategies to enhance the competitiveness of IT industry. For example, the Japan government proposed the "Green IT initiative" for being compatible with economic growth and environmental protection. Not only energy saving technologies but energy saving systems have been developed for accomplishing sustainable development. Korea's CO2 emission and energy consumption continuously have grown at comparatively high rates. They are related to its industrial structure depending on high energy-consuming industries such as iron and steel Industry, automotive industry, shipbuilding industry, semiconductor industry, and so on. In particular, export proportion of IT manufacturing is quite high in Korea. For example, the global market share of the semiconductor such as DRAM was about 80% in 2008. Accordingly, Korea needs to establish a systematic strategy to respond to the global environmental regulations and to maintain competitiveness in the IT industry. However, green competitiveness of Korea ranked 11th among 15 major countries and R&D budget for green technology is not large enough to develop energy-saving technologies for infrastructure and value chain of low-carbon society though that grows at high rates. Moreover, there are no concrete action plans in Korea. This research aims to deduce the priorities of the Korean green business/IT strategies to use multi attribute weighted average method. We selected a panel of 19 experts who work at the green business related firms such as HP, IBM, Fujitsu and so on, and selected six assessment indices such as the urgency of the technology development, the technology gap between Korea and the developed countries, the effect of import substitution, the spillover effect of technology, the market growth, and the export potential of the package or stand-alone products by existing literature review. We submitted questionnaires at approximately weekly intervals to them for priorities of the green business/IT strategies. The strategies broadly classify as follows. The first strategy which consists of the green business/IT policy and standardization, process and performance management and IT industry and legislative alignment relates to government's role in the green economy. The second strategy relates to IT to support environment sustainability such as the travel and ways of working management, printer output and recycling, intelligent building, printer rationalization and collaboration and connectivity. The last strategy relates to green IT systems, services and usage such as the data center consolidation and energy management, hardware recycle decommission, server and storage virtualization, device power management, and service supplier management. All the questionnaires were assessed via a five-point Likert scale ranging from "very little" to "very large." Our findings show that the IT to support environment sustainability is prior to the other strategies. In detail, the green business /IT policy and standardization is the most important in the government's role. The strategies of intelligent building and the travel and ways of working management are prior to the others for supporting environment sustainability. Finally, the strategies for the data center consolidation and energy management and server and storage virtualization have the huge influence for green IT systems, services and usage This research results the following implications. The amount of energy consumption and CO2 emissions of IT equipment including electrical business equipment will need to be clearly indicated in order to manage the effect of green business/IT strategy. And it is necessary to develop tools that measure the performance of green business/IT by each step. Additionally, intelligent building could grow up in energy-saving, growth of low carbon and related industries together. It is necessary to expand the affect of virtualization though adjusting and controlling the relationship between the management teams.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.2
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• pp.272-285
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• 2003

This study was conducted to observe the microscopic structures of cavities formed after ablation of primary teeth, permanent teeth, enamel and dentin in using a bur and cavities formed after ablation using laser and the following results were obtained after comparing the effects of ablation. Using a #330 bur and Er:YAG laser irradiated at 150 mJ, 200 mJ, 250 mJ and 300 mJ all at the frequency of 5 Hz, 1 mm enamel and dentin samples were ablated and the ablation time was measured. In order to measure the surfaces ablated, 5 each of primary teeth and permanent teeth were ablated using a #330 bur and Er:YAG laser at 150 mJ, 200 mJ, 250 mJ and 300 mJ for 1 sec and the cross section and vertical section were observed. The following results were obtained : 1. Cutting time of Er:YAG laser was longer than that of conventinal high-speed bur regardless of teeth type. 2. Cutting on enamel, Cutting time of conventional high-speed bur in deciduous teeth was longer than in permanent teeth(P<0.05). But Er:YAG laser was not showed any difference between the deciduous and permanent teeth(P>0.05). 3. Cutting on dentin, Cutting time of conventional high-speed bur in permanent teeth was longer than deciduous teeth. Er:YAG laser of 150 mJ, 5 Hz in permanent teeth was longer than in deciduous teeth(p<0.05). But laser of other power did not showed mean difference. 4. The cavity surface treated with the convetional high-speed bur revealed a relatively flat appearance, almost covered with a debris-like smear layer. Cavity wall showed striped appearance because of blade of bur. 5. The cavity surface treated by the Er:YAG laser system was irregular or rough surface with the absence charring, carbonization, or cracking of the dentin. In addition, there was an absence of a smear layer. Cavity floor was round and relatively smooth. According to these results, cutting time of Er:YAG laser was almostly same in permanent and deciduous teeth, but more effective in dentin than enamel. Cutting the sample, Er:YAG laser was needed more time than conventional bur. But SEM findings suggested that laser device produced favorable surface characteristic(i.e, no smear layer, irregular surface, cracking).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.126-134
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• 2017

There have been numerous studies on extracting the R-peak from electrocardiogram (ECG) signals. However, most of the detection methods are complicated to implement in a real-time portable electrocardiograph device and have the disadvantage of requiring a large amount of calculations. R-peak detection requires pre-processing and post-processing related to baseline drift and the removal of noise from the commercial power supply for ECG data. An adaptive filter technique is widely used for R-peak detection, but the R-peak value cannot be detected when the input is lower than a threshold value. Moreover, there is a problem in detecting the P-peak and T-peak values due to the derivation of an erroneous threshold value as a result of noise. We propose a robust R-peak detection algorithm with low complexity and simple computation to solve these problems. The proposed scheme removes the baseline drift in ECG signals using an adaptive filter to solve the problems involved in threshold extraction. We also propose a technique to extract the appropriate threshold value automatically using the minimum and maximum values of the filtered ECG signal. To detect the R-peak from the ECG signal, we propose a threshold neighborhood search technique. Through experiments, we confirmed the improvement of the R-peak detection accuracy of the proposed method and achieved a detection speed that is suitable for a mobile system by reducing the amount of calculation. The experimental results show that the heart rate detection accuracy and sensitivity were very high (about 100%).

• Korean Security Journal
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• no.39
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• pp.319-353
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• 2014

Cyber-based technologies are now ubiquitous around the glob and are emerging as an "instrument of power" in societies, and are becoming more available to a country's opponents, who may use it to attack, degrade, and disrupt communications and the flow of information. The globe-spanning range of cyberspace and no national borders will challenge legal systems and complicate a nation's ability to deter threats and respond to contingencies. Through cyberspace, competitive powers will target industry, academia, government, as well as the military in the air, land, maritime, and space domains of our nations. Enemies in cyberspace will include both states and non-states and will range from the unsophisticated amateur to highly trained professional hackers. In much the same way that airpower transformed the battlefield of World War II, cyberspace has fractured the physical barriers that shield a nation from attacks on its commerce and communication. Cyberthreats to the infrastructure and other assets are a growing concern to policymakers. In 2013 Cyberwarfare was, for the first time, considered a larger threat than Al Qaeda or terrorism, by many U.S. intelligence officials. The new United States military strategy makes explicit that a cyberattack is casus belli just as a traditional act of war. The Economist describes cyberspace as "the fifth domain of warfare and writes that China, Russia, Israel and North Korea. Iran are boasting of having the world's second-largest cyber-army. Entities posing a significant threat to the cybersecurity of critical infrastructure assets include cyberterrorists, cyberspies, cyberthieves, cyberwarriors, and cyberhacktivists. These malefactors may access cyber-based technologies in order to deny service, steal or manipulate data, or use a device to launch an attack against itself or another piece of equipment. However because the Internet offers near-total anonymity, it is difficult to discern the identity, the motives, and the location of an intruder. The scope and enormity of the threats are not just focused to private industry but also to the country's heavily networked critical infrastructure. There are many ongoing efforts in government and industry that focus on making computers, the Internet, and related technologies more secure. As the national intelligence institution's effort, cyber counter-intelligence is measures to identify, penetrate, or neutralize foreign operations that use cyber means as the primary tradecraft methodology, as well as foreign intelligence service collection efforts that use traditional methods to gauge cyber capabilities and intentions. However one of the hardest issues in cyber counterintelligence is the problem of "Attribution". Unlike conventional warfare, figuring out who is behind an attack can be very difficult, even though the Defense Secretary Leon Panetta has claimed that the United States has the capability to trace attacks back to their sources and hold the attackers "accountable". Considering all these cyber security problems, this paper examines closely cyber security issues through the lessons from that of U.S experience. For that purpose I review the arising cyber security issues considering changing global security environments in the 21st century and their implications to the reshaping the government system. For that purpose this study mainly deals with and emphasis the cyber security issues as one of the growing national security threats. This article also reviews what our intelligence and security Agencies should do among the transforming cyber space. At any rate, despite of all hot debates about the various legality and human rights issues derived from the cyber space and intelligence service activity, the national security should be secured. Therefore, this paper suggests that one of the most important and immediate step is to understanding the legal ideology of national security and national intelligence.

• Journal of the Korean Magnetics Society
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• v.25 no.3
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• pp.67-73
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• 2015

This is a basic research for improving soft magnetic property of Fe based nano crystalline alloy powder core. The main study is done around characteristics of permeability, core loss, and DC bias depending on amount of insulation coating agent and particle size. First, $Fe_{73.5}Si_{13.5}B_9Nb_3Cu_1$ amorphous alloy ribbon was fabricated by using the planar flow casting (PFC) device. Then, heat treatment and ball milling were done to obtain alloy powder. The amount of polyether imide (PEI) added to it was varied by 0.5, 1.0, 2.0, 2.5 wt% to have compression molding into $16ton/cm^2$. After going through crystalline heat treatment, the made toroidal nano crystalline powder core ($OD12.7mm^*ID7.62mm^*H4.75mm$) had smaller permeability as amount of insulation coating agent decreases. However, it was found out that core loss and DC bias characteristics have been improved. The reason for this results were expected to be because green density of power core decreases as amorphous alloy powder particles become smaller as amount of alloy powder insulation coating agent increases, it was determined that 1 wt% of insulation coating agent is appropriate. Also, for powder core made based on alloy powder size with amount of insulation coating agent fixed at 1 wt%, effective permeability and core loss were outstanding as particle size became bigger. However, characteristics of DC bias became worse as applied DC field increases. This is expected to be due to insulation effect, residual pores, or molding density of powder core resulting from thickness of coating on surface of alloy powder.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.7
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• pp.380-394
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• 2015

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2014. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of heat and mass transfer, cooling and heating, and air-conditioning, the flow inside building rooms, and smoke control on fire. Research issues dealing with duct and pipe were reduced, but flows inside building rooms, and smoke controls were newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for thermal contact resistance measurement of metal interface, a fan coil with an oval-type heat exchanger, fouling characteristics of plate heat exchangers, effect of rib pitch in a two wall divergent channel, semi-empirical analysis in vertical mesoscale tubes, an integrated drying machine, microscale surface wrinkles, brazed plate heat exchangers, numerical analysis in printed circuit heat exchanger. In the area of pool boiling and condensing, non-uniform air flow, PCM applied thermal storage wall system, a new wavy cylindrical shape capsule, and HFC32/HFC152a mixtures on enhanced tubes, were actively studied. In the area of industrial heat exchangers, researches on solar water storage tank, effective design on the inserting part of refrigerator door gasket, impact of different boundary conditions in generating g-function, various construction of SCW type ground heat exchanger and a heat pump for closed cooling water heat recovery were performed. (3) In the field of refrigeration, various studies were carried out in the categories of refrigeration cycle, alternative refrigeration and modelling and controls including energy recoveries from industrial boilers and vehicles, improvement of dehumidification systems, novel defrost systems, fault diagnosis and optimum controls for heat pump systems. It is particularly notable that a substantial number of studies were dedicated for the development of air-conditioning and power recovery systems for electric vehicles in this year. (4) In building mechanical system research fields, seventeen studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, and renewable energies, piping in the buildings. Proposed designs, performance performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the evaluation of work noise in tunnel construction and the simulation and development of a light-shelf system. The subjects of building energy were worked on the energy saving of office building applied with window blind and phase change material(PCM), a method of existing building energy simulation using energy audit data, the estimation of thermal consumption unit of apartment building and its case studies, dynamic window performance, a writing method of energy consumption report and energy estimation of apartment building using district heating system. The remained studies were related to the improvement of architectural engineering education system for plant engineering industry, estimating cooling and heating degree days for variable base temperature, a prediction method of underground temperature, the comfort control algorithm of car air conditioner, the smoke control performance evaluation of high-rise building, evaluation of thermal energy systems of bio safety laboratory and a development of measuring device of solar heat gain coefficient of fenestration system.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.12
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• pp.1098-1125
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• 2000

A review on the papers published in the Korean Journal of Air-Conditioning and Refrigerating Engineering in 1998 and 1999 has been done. Focus has been put on current status of research in the aspect of heating, cooling, ventilation, sanitation and building environment. The conclusions are as follows. 1) A review of the recent studies on fluid flow, turbomachinery and pipe-network shows that many experimental investigations are conducted in applications of impingement jets. Researches on turbulent flows, pipe flows, pipe-networks are focused on analyses of practical systems and prediction of system performance. The results of noise reduction in the turbomachinery are also reported. 2) A review of the recent studies on heat transfer analysis and heat exchanger shows that there were many papers on the channel flow with the application to the design of heat exchanger in the heat transfer analysis. Various experimental and numerical papers on heat exchanger were also published, however, there were few papers available for the analysis of whole system including heat exchanger. 3) A review of the recent studies on heat pump system have focused on the multi-type system and the heat pump cycle to utilize treated sewage as the heat source. The defrosting and the frosting behaviors in the fin-tube heat exchanger is experimentally examined by several authors. Several papers on the ice storage cooling system are presented to show the dynamic simulation program and optimal operation conditions. The study on the micro heat pipes for the cooling of high power electronic components is carried out to examine the characteristics of heat and mass transfer processed. In addition to these, new type of separate thermosyphon is studied experimentally. 4) The recent studies on refrigeration/air conditioning system have focused on the system performance and efficiency for new alternative refrigerants. New systems operating with natural refrigerants are drawing lots of attention. In addition to these, evaporation and condensation heat transfer characteristics of traditional and new refrigerants are investigated for plain tubes and also for microfin tubes. Capillary tubes and orifice are main topics of research as expansion devices and studies on thermophysical properties of new refrigerants and refrigerant/oil mixtures are widely carried out. 5) A review of the recent studies on absorption cooling system shows that numerous experimental and analytical studies on the improvement of absorber performance have been presented. Dynamic analysis of compressor have been performed to understand its vibration characteristics. However research works on tow-phase flow and heat transfer, which could be encountered in the refrigeration system and various phase-change heat exchanger, were seemed to be insufficient. 6) A review of recent studies on duct system shows that the methods for circuit analysis, and flow balancing have been presented. Researches on ventilation are focused on the measurement of ventilation efficiency, and variation of ventilation efficiency with ventilation methods by numerous experimental and numerical studies. Furthermore, many studies have been conducted in real building in order to estimate indoor thermal environments. Many research works to get some information for cooling tower design have been performed but are insufficient. 7) A review on the recent studies on architectural thermal environment and building mechanical systems design shows that thermal comfort analysis is sitting environment, thermal performance analysis of Korean traditional building structures., and evaluation of building environmental load have been performed. However research works to improve the performance of mechanical system design and construction technology were seemed to be insufficient.

• Journal of Oral Medicine and Pain
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• v.30 no.1
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• pp.69-77
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• 2005

The purposes of this study were to develop and introduce a novel intraoral appliance for bruxism composed of power switch and biofeedback device and further to examine inter- and intra-reliability of the appliance prior to clinical tests. The newly-developed appliance consisted of detection sensors, a central processing unit (CPU), a reactor and a storage unit and a displayer. Compact-sized, waterproof switches were selected as bruxism detection sensor and any sensor activation by clenching or grinding event was processed at the CPU and transmitted, by radio wave, to the reactor and storage unit and triggered auditory or vibratory signal, subsequently producing biofeedback to the patient with bruxism. The data on bruxing event in the storage unit can be displayed on the computer, making it possible analyzing frequency, duration and nature of bruxism. Cast models were obtained from ten volunteers with normal occlusion to evaluate reliability of the appliances. For inter-operator reliability on the intraoral appliances, each operator of the two fabricated the appliance for the same subject and compared the minimal contact forces provoking auditory biofeedback reaction in vertical, lateral and central directions. Intra-operator reliability was also investigated on the appliances made by a single operator at two separate times with an interval of two days. Conclusively, the newly-developed appliance is compact and safe to use in oral circumstance and easy to make. Furthermore, it had to be proven reliability excellent enough to apply in clinical settings. Thus, it is assumed that this appliance with the processor and the storage of data and auditory or vibratory biofeedback function is available and useful to analyze and control bruxism.

• Clinical and Experimental Reproductive Medicine
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• v.4 no.1
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• pp.17-25
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• 1977

Anderson(1937), Power and Barnes(1941) reported a study concerning a method of tubal sterilization in association with peritoneoscopy or laparoscopy in which they cauterized the tubes. There appears to have been a hiatus of interest in sterilization (cold or hot) associated with laparoscopy until reintroduction by Palmer(1963), Frangenheim(1964) and Steptoe(1967). On the other hand, for interval female sterilization, however, minilaparotomy is relatively new. By Saunder and Munsick(1972), John Lyle(1974), Frank Stubb(1974), Vitoon(1973) and B.C. Bai(1975), their own technique for interval female sterilization requires 2.0 to 2.5cm, incision at the margin of the mons pubis. In Korea, female sterilization by means of minilaparotomy firstly reported by B.C. Bai using Bai's uterine elevator, of his own device, early in 1975. Recently inteval female sterilization by laparoscopy and minilaparotomy are widely accepted throughout the world especially in Asian countries. Minilaparotomy is carried out from 1974, laparoscopic sterilization from 1976, and in this study each of 250 cases of those were analysed and discussed for the comparison at Seoul Red Cross Hospital. (1) In the age distribution, numerous clients were in their age of $31{\sim}35$ in laparoscopy as well as minilaparotomy. Average 33.7 years in L and 33.2 years in M. (M=minilaparotomy, L=laparoscopic sterilization) (2) As regarding living children, women having 3 children represented the greatest number, 113 cases out of 250 in M group and 102 cases out of 250 in L group. Average No. of child are 2.9 in Land 3.1 in M. (3) Concidering the operation day in the menstrml cycle, the greatest number of cases, those who underwent tubal sterilization during the days of $26{\sim}$, next during the $6{\sim}10$ days of the cycle in both group. (4) Concidering the operation time, 188 cases by laparoscopy were performed in $6{\sim}10$ minutes, 33 cases within 5 minutes and 24 cases in $11{\sim}15$ minutes. Maximum 50 minutes, minimum 4 minutes and average 8.3 minutes. The majority of cases (154 cases) by minilaparotomy required $6{\sim}10$ minutes and 67 cases $11{\sim}15$ minutes, 6 cases within 5 minutes. Maximum 30 minutes, minimum 4 minutes and average 10.4, minutes. In both groups, most of the reasons for the extra length were surgical difficulties such as thick abdominal wall, pelvic adhesion, less cooperation of patients in early period of this study. (5) Hospital stay after operation in L group required $3{\sim}4$ hours in 125 cases, $2{\sim}3$ hours in 41 cases, $4{\sim}5$ hours in 32 cases out of 250. Maximum 8 hours, minimum 1 hour and average 3.8 hours. In M group hospital stay required $6{\sim}7$ hours in 100 cases, over 7 hours in 85 cases, $5{\sim}6$ hours in 46 cases and so on. Maximum 14 hours, minimum 2 hours and average 6.5 hours. (6) The time between operation and gas passing in the majority cases of both groups, were $12{\sim}36$ hours. A veragetime 20.3 hours in L and 27.2 in M. (7) Laparoscopic sterilization coincident with induced abortion were carried out in 27 cases, laparoscopy with minilaparotomy to control for mesosalpingeal hemorrhage in 1 case. Minilaparotomy coincident with induced abortion were performed in 65 cases, D and C whit polypectomy, menstrual regulatian, and remaval of IUD in 1 case respectively. (8) In L group, 1 case of mesosalpingeal hemorrhage, 1 case of abdominal wall infection were complicated during operation. In M group, 1 case of uterine perfaration, 1 case of abdominal wall infection, 1 case of hemorrhage from omentum and 1 case of bloody vaginal discharge were complicated. No intensive medical treatment was required for those minor complications in both groups. (9) No failure has been recognized and these two sterilization techniques might be the simple, safe and the most effective method for permanent contraception at present time. There is no significant clinical defference between L and M group in this study.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.3
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• pp.46-55
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• 2016

This work proposes a 13b 100MS/s 45nm CMOS ADC with a high dynamic performance for IF-domain high-speed signal processing systems based on a four-step pipeline architecture to optimize operating specifications. The SHA employs a wideband high-speed sampling network properly to process high-frequency input signals exceeding a sampling frequency. The SHA and MDACs adopt a two-stage amplifier with a gain-boosting technique to obtain the required high DC gain and the wide signal-swing range, while the amplifier and bias circuits use the same unit-size devices repeatedly to minimize device mismatch. Furthermore, a separate analog power supply voltage for on-chip current and voltage references minimizes performance degradation caused by the undesired noise and interference from adjacent functional blocks during high-speed operation. The proposed ADC occupies an active die area of $0.70mm^2$, based on various process-insensitive layout techniques to minimize the physical process imperfection effects. The prototype ADC in a 45nm CMOS demonstrates a measured DNL and INL within 0.77LSB and 1.57LSB, with a maximum SNDR and SFDR of 64.2dB and 78.4dB at 100MS/s, respectively. The ADC is implemented with long-channel devices rather than minimum channel-length devices available in this CMOS technology to process a wide input range of $2.0V_{PP}$ for the required system and to obtain a high dynamic performance at IF-domain input signal bands. The ADC consumes 425.0mW with a single analog voltage of 2.5V and two digital voltages of 2.5V and 1.1V.