• Journal of Power Electronics
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• v.15 no.4
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• pp.1131-1138
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• 2015

This study presents an input-powered high-efficiency interface circuit for energy harvesting systems, and introduces a zero standby power design to reduce power consumption significantly while removing the external power supply. This interface circuit is composed of two stages. The first stage voltage doubler uses a positive feedback control loop to improve considerably the conversion speed and efficiency, and boost the output voltage. The second stage active diode adopts a common-grid operational amplifier (op-amp) to remove the influence of offset voltage in the traditional comparator, which eliminates leakage current and broadens bandwidth with low power consumption. The system supplies itself with the harvested energy, which enables it to enter the zero standby mode near the zero crossing points of the input current. Thereafter, high system efficiency and stability are achieved, which saves power consumption. The validity and feasibility of this design is verified by the simulation results based on the 65 nm CMOS process. The minimum input voltage is down to 0.3 V, the maximum voltage efficiency is 99.6% with a DC output current of 75.6 μA, the maximum power efficiency is 98.2% with a DC output current of 40.4 μA, and the maximum output power is 60.48 μW. The power loss of the entire interface circuit is only 18.65 μW, among which, the op-amp consumes only 2.65 μW.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.11
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• pp.6965-6969
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• 2013

Background: Tobacco consumption has been identified as the single biggest cause of inequality in morbidity and mortality. Understanding pattern of socioeconomic equalities in tobacco consumption in India will help in designing targeted public health control measures. Materials and Methods: Nationally representative data from the India Global Adult Tobacco Survey (GATS) conducted in 2009-2010 was analyzed. The survey provided information on 69,030 respondents aged 15 years and above. Data were analyzed according to regions for estimating prevalence of current tobacco consumption (both smoking and smokeless) across wealth quintiles. Multiple logistic regression analysis predicted the impact of socioeconomic determinants on both forms of current tobacco consumption adjusting for other socio-demographic variables. Results: Trends of smoking and smokeless tobacco consumption across wealth quintiles were significant in different regions of India. Higher prevalence of smoking and smokeless tobacco consumption was observed in the medium wealth quintiles. Risk of tobacco consumption among the poorest compared to the richest quintile was 1.6 times higher for smoking and 3.1 times higher for smokeless forms. Declining odds ratios of both forms of tobacco consumption with rising education were visible across regions. Poverty was a strong predictor in north and south Indian region for smoking and in all regions for smokeless tobacco use. Conclusions: Poverty and poor education are strong risk factors for both forms of tobacco consumption in India. Public health policies, therefore, need to be targeted towards the poor and uneducated.

• Nutrition Research and Practice
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• v.13 no.5
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• pp.425-433
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• 2019

BACKGROUND/OBJECTIVES: The International Agency for Research on Cancer defined alcohol beverages and acetaldehyde derived from alcoholic beverages as a Group 1 carcinogen to humans. However, the association between alcohol consumption and gastric cancer risk has been controversial in Korean. We assessed the relationship between alcohol consumption and gastric cancer risk in Korea through a case-control study. SUBJECTS/METHODS: From 2 hospitals, a total of 316 cases with gastric cancer (208 men, 108 women) were selected and matched to 316 controls by sex and age (${\pm}5years$) during the same duration. The current status, frequency, and amount of alcohol consumption for a year three years ago were assessed by trained interviewers. RESULTS: Alcohol consumption status and frequency did not show any significant association with gastric cancer risk. However, high alcohol consumption (${\geq}20g/day$ for women or ${\geq}40g/day$ for men) significantly increased the risk of gastric cancer (odds ratio (OR) 1.73; 95% confidence interval (CI) 1.05-2.85). Gastric cancer risk was strongly positively associated with alcohol consumption of ${\geq}20g/day$, especially in women (OR 5.62; 95% CI 1.32-23.81). CONCLUSION: The results from this study suggest that excessive alcohol consumption rather than the current status or frequency of alcohol consumption contributes to the increased risk of gastric cancer, especially in women.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.7
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• pp.659-664
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• 2016

In this paper, we suggest operational trans-conductance amplifier(OTA) for current-mode FIR filter that can be used in a digital circuit system requiring high operating frequency and low power consumption. The current-mode signal processing is one of the very innovative design method for a low power consumption system with high operating frequency because it shows a constant power regardless of frequency. From the simulation result using 0.35um CMOS process, when Vdd is 2V, it is confirmed that the proposed circuit showed the dynamic range of the about 1V, about 50% of supply voltage and output current swing of about 0~200uA. Also, the power consumption was evaluated with about 21uW and the active size for an integration was measured with $71um{\times}166um$.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.5
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• pp.1-10
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• 1999

A low power concumption 2.4 GHz one-chip transceiver MMIC was designed and fabricated using $1.0\mu\textrm{m}$ ion-implantation MESFET process and packaged on a 24 lead SSOP. In the transmitter mode, it revealed conversion gain of 7.5 dB, output IP3 of -3.5 dBm, and noise figure of 3.9 dB at 2.44 GHz with 3.9 mA current consumption. In the receiver mode, it revealed voltage sensitivity of 6.5 mV/$\mu\$W with 2 .0 mA current consumption. Comparing the fabricated MMIC with the results of MMICs reported elsewhere, it was shown that the fabricated MMIC had good performance. The low power consumption 2.4 GHz transceiver MMIC is expected to be used for various applications such as wireless local area networks, wireless local loops and RFID tags in ISM-band.

• Membrane and Water Treatment
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• v.1 no.1
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• pp.13-37
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• 2010

The performance of an electrodialyzer for concentrating seawater is predicted by means of a computer simulation, which includes the following five steps; Step 1 mass transport; Step 2 current density distribution; Step 3 cell voltage; Step 4 NaCl concentration in a concentrated solution and energy consumption; Step 5 limiting current density. The program is developed on the basis of the following assumption; (1) Solution leakage and electric current leakage in an electrodialyzer are negligible. (2) Direct current electric resistance of a membrane includes the electric resistance of a boundary layer formed on the desalting surface of the membrane due to concentration polarization. (3) Frequency distribution of solution velocity ratio in desalting cells is equated by the normal distribution. (4) Current density i at x distant from the inlets of desalting cells is approximated by the quadratic equation. (5) Voltage difference between the electrodes at the entrance of desalting cells is equal to the value at the exits. (6) Limiting current density of an electrodialyzer is defined as average current density applied to an electrodialyzer when current density reaches the limit of an ion exchange membrane at the outlet of a desalting cell in which linear velocity and electrolyte concentration are the least. (7) Concentrated solutions are extracted from concentrating cells to the outside of the process. The validity of the computer simulation model is demonstrated by comparing the computed results with the performance of electrodialyzers operating in salt-manufacturing plants. The model makes it possible to discuss optimum specifications and operating conditions of a practical-scale electrodialyzer.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.5
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• pp.342-348
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• 2011

This study analyzes the current and after retrofit energy consumption of lighting and cooling system of a superstore in Seoul. Energy consumption data were measured and collected with a measurement system. Annual energy consumption was calculated using TRNSYS program. After replacing lighting and chiller with higher efficiencies, annual TOE consumption decreased from 1,066 before retrofit to 832 after retrofit, saving 234 TOE (22%) in total. Similarly, total annual $TCO_2$ consumption decreased from 2,214 to 1,721, reducing 493 $TCO_2$ (22%) during this pilot study.

• Korean Journal of Organic Agriculture
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• v.20 no.1
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• pp.1-19
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• 2012

The purpose of this study is to analyze consumption of homemade organically processed food (HOPF), and to derive directions for consumption promotion of HOPF. A survey was conducted for quantitative analysis regarding consumption. This study used an Ordinal Logistic Regression Model to derive more significant results in analyzing factors of consumption. The findings was that younger consumers with high income are more likely to purchase HOPF. And those consumers with high price and quality contentment are more likely to purchase HOPF. And contentment with certification institutions and improvement of health have a significant positive relationship with consumption. Consumers were found to pay 51 percent more for HOPF than for non-HOPF products. This level show that the current level of price premium for HOPF is 51 percent higher than their desired level. In order to reduce the price premium for HOPF, effective policy programs should be developed. A targeted market strategy to sell HOPF to younger consumers with high income is needed to boost consumption. A strict certification management system should be established to enhance consumer reliability in HOPF.

• Journal of Korea Port Economic Association
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• v.25 no.2
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• pp.231-246
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• 2009

The time charterer depends on speed and bunker consumption rate of time chartered vessel because it is related charterers' benefit. It is important role of stipulated speed and daily bunker consumption rate at the Time Charter Party, it is generated any dispute against speed and daily bunker consumption rate deficiency. The case of dispute is a restricted word of stipulated speed and daily bunker consumption rate at Charter Party as "about", "good weather or good weather day", "smooth water", "ocean current" and "without guarantee". It happens a dispute against speed and daily bunker consumption rate because it is not well-educated as a vessel operator regarding Time Charter Party interpretation.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.2
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• pp.212-215
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• 2016

In this paper, a 5.08 GHz Ring Voltage Controlled Oscillator(Ring VCO) was implemented using $0.18{\mu}m$ standard CMOS technology. The proposal Ring VCO is 3-stage structure. This research confirmed that the each stage's different transistor size ratio influence the current change and alter power consumption consequentially. This circuit is formed to control the current thereby adding the Current Mirror and to tune the frequency by supplying control voltage. It has an 65.5 %(1.88~5.45 GHz) tuning range. The measured output power is -0.30 dBm. The phase noise is -87.50 dBc/Hz @1 MHz offset with operating frequency of 5.08 GHz fundamental frequency. The total power consumption of Ring VCO is 31.2 mW with 2.4 V supply voltage.