• Communications of the Korean Institute of Information Scientists and Engineers
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• v.28 no.7
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• pp.89-96
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• 2010

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.9A
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• pp.1368-1376
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• 2000

This paper describes the codesign method for IS-95 based CDMA(Code Division Multiple Access). By codesign we mean to design hardware and software simultaneously. Codesign lead to reduction in design time, cost and power consumption. When we partition a system into hardware and software, some modules with longer processing time and larger power consumption are implemented using hardware and the remaining part is implemented using software. In proposed design, we design the synchronous accumulator of CDMA searcher in hardware and the other part in software, The hardware part is designed using VHDL, while software part is designed using GC(Generic C). We simulated and verified the system using COSSAP in SYNOPSYSTM. Experimentation showed the maximum 48.5% speed reduction compared with the design using software only.

• Nutrition Research and Practice
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• v.10 no.5
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• pp.530-536
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• 2016

BACKGROUND/OBJECTIVES: The concept of "food deserts" has been widely used in Western countries as a framework to identify areas with constrained access to fresh and nutritious foods, providing guidelines for targeted nutrition and public health programs. Unlike the vast amount of literature on food deserts in a Western context, only a few studies have addressed the concept in an East Asian context, and none of them have investigated spatial patterns of unhealthy food consumption from a South Korean perspective. SUBJECTS/METHODS: We first evaluated the applicability of food deserts in a Korean setting and identified four Korean-specific unhealthy food consumption indicators, including insufficient food consumption due to financial difficulty, limited consumption of fruits and vegetables, excessive consumption of junk food, and excessive consumption of instant noodles. The KNHANES 2008-2012 data in Seoul were analyzed with stratified sampling weights to understand the trends and basic characteristics of these eating patterns in each category. GIS analyses were then conducted for the data spatially aggregated at the sub-district level in order to create maps identifying areas of concern regarding each of these indicators and their combinations. RESULTS: Despite significant reduction in the rate of food insufficiency due to financial difficulty, the rates of excessive consumption of unhealthy foods (junk food and instant noodles) as well as limited consumption of fruits and vegetables have increased or remained high. These patterns tend to be found among relatively younger and more educated groups, regardless of income status. CONCLUSIONS: A GIS-based analysis demonstrated several hotspots as potential "food deserts" tailored to the Korean context based on the observed spatial patterns of undesirable food consumption. These findings could be used as a guide to prioritize areas for targeted intervention programs to facilitate healthy food consumption behaviors and thus improve nutrition and food-related health outcomes.

• Advances in nano research
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• v.15 no.6
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• pp.521-531
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• 2023

Quantum-dot cellular automata (QCA) has shown great potential in the nanoscale regime as a replacement for CMOS technology. This work presents a specific approach to static random-access memory (SRAM) cell based on 2:1 multiplexer, 4-bit SRAM array, and 32-bit SRAM array in QCA. By utilizing the proposed SRAM array, a single-layer 16×32-bit SRAM with the read/write capability is presented using an optimized signal distribution network (SDN) crossover technique. In the present study, an extremely-optimized 2:1 multiplexer is proposed, which is used to implement an extremely-optimized SRAM cell. The results of simulation show the superiority of the proposed 2:1 multiplexer and SRAM cell. This study also provides a more efficient and accurate method for calculating QCA costs. The proposed extremely-optimized SRAM cell and SRAM arrays are advantageous in terms of complexity, delay, area, and QCA cost parameters in comparison with previous designs in QCA, CMOS, and FinFET technologies. Moreover, compared to previous designs in QCA and FinFET technologies, the proposed structure saves total energy consisting of overall energy consumption, switching energy dissipation, and leakage energy dissipation. The energy and structural analyses of the proposed scheme are performed in QCAPro and QCADesigner 2.0.3 tools. According to the simulation results and comparison with previous high-quality studies based on QCA and FinFET design approaches, the proposed SRAM reduces the overall energy consumption by 25%, occupies 33% smaller area, and requires 15% fewer cells. Moreover, the QCA cost is reduced by 35% compared to outstanding designs in the literature.

• ETRI Journal
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• v.37 no.3
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• pp.480-490
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• 2015

The reliability of sensor networks is generally dependent on the battery power of the sensor nodes that it employs; hence it is crucial for the sensor nodes to efficiently use their battery resources. This research paper presents a method to increase the reliability of sensor nodes by constructing a connected dominating tree (CDT), which is a subnetwork of wireless sensor networks. It detects the minimum number of dominatees, dominators, forwarder sensor nodes, and aggregates, as well as transmitting data to the sink. A new medium access control (MAC) protocol, called Homogenous Quorum-Based Medium Access Control (HQMAC), is also introduced, which is an adaptive, homogenous, asynchronous quorum-based MAC protocol. In this protocol, certain sensor nodes belonging to a network will be allowed to tune their wake-up and sleep intervals, based on their own traffic load. A new quorum system, named BiQuorum, is used by HQMAC to provide a low duty cycle, low network sensibility, and a high number of rendezvous points when compared with other quorum systems such as grid and dygrid. Both the theoretical results and the simulation results proved that the proposed HQMAC (when applied to a CDT) facilitates low transmission latency, high delivery ratio, and low energy consumption, thus extending the lifetime of the network it serves.

• IEMEK Journal of Embedded Systems and Applications
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• v.11 no.2
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• pp.97-105
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• 2016

Microcontrollers (MCUs) for endpoint smart sensor devices of internet-of-thing (IoT) are being implemented as system-on-chip (SoC) with on-chip instruction flash memory, in which user firmware is embedded. MCUs directly fetch binary code-based instructions through bit-line sense amplifier (S/A) integrated with on-chip flash memory. The S/A compares bit cell current with reference current to identify which data are programmed. The S/A in reading '0' (erased) cell data consumes a large sink current, which is greater than off-current for '1' (programmed) cell data. The main motivation of our approach is to reduce the number of accesses of erased cells by binary code level transformation. This paper proposes a built-in write/read path architecture using binary code inversion method based on hot-spot region detection of instruction code access to reduce sensing current in S/A. From the profiling result of instruction access patterns, hot-spot region of an original compiled binary code is conditionally inverted with the proposed bit-inversion techniques. The de-inversion hardware only consumes small logic current instead of analog sink current in S/A and it is integrated with the conventional S/A to restore original binary instructions. The proposed techniques are applied to the fully-custom designed MCU with ARM Cortex-M0$^{TM}$ using 0.18um Magnachip Flash-embedded CMOS process and the benefits in terms of power consumption reduction are evaluated for Dhrystone$^{TM}$ benchmark. The profiling environment of instruction code executions is implemented by extending commercial ARM KEIL$^{TM}$ MDK (MCU Development Kit) with our custom-designed access analyzer.

• JSTS:Journal of Semiconductor Technology and Science
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• v.2 no.3
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• pp.197-204
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• 2002

DRAM, SRAM, and FLASH memory are three major memory devices currently used in most electronic applications. But, they have very distinct attributes, therefore, each memory could be used only for limited applications. MRAM (Magneto-resistive Random Access Memory) is a promising candidate for a universal memory that meets all application needs with non-volatile, fast operational speed, and low power consumption. The simplest architecture of MRAM cell is a series of MTJ (Magnetic Tunnel Junction) as a data storage part and MOS transistor as a data selection part. To be a commercially competitive memory device, scalability is an important factor as well. This paper is testing the actual electrical parameters and the scaling factors to limit MRAM technology in the semiconductor based memory device by an actual integration of MRAM core cell. Electrical tuning of MOS/MTJ, and control of resistance are important factors for data sensing, and control of magnetic switching for data writing.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.1
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• pp.123-140
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• 2011

In this paper, we propose an Energy Efficient Media Access Control (EE-MAC) protocol for wireless sensor networks. The proposed scheme is designed to save power consumption and guarantee quality-of-service for real-time traffic. EE-MAC uses the superframe structure which is bounded by the transmission of a beacon frame and can have an active and an inactive portion. The active period is divided into the contention free period (CFP) for real-time traffic transmission and the contention access period (CAP) for non-real-time traffic transmission. We propose the exclusively allocated backoff scheme which assigns a unique backoff time value to each real-time node based on bandwidth allocation and admission control. This scheme can avoid collision between real-time nodes by controlling distributed fashion and take effect a statistical time division multiple access. We also propose the algorithm to change the duty cycle adaptively according to channel utilization of media depending on network traffic load. This algorithm can prolong network lifetime by reducing the amount of energy wasted on idle listening.

• Food Science of Animal Resources
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• v.34 no.1
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• pp.7-13
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• 2014

The consumption of animal flesh food in Ethiopia has associated with cultural practices. Meat plays pivotal and vital parts in special occasions and its cultural symbolic weight is markedly greater than that accorded to most other food. Processing and cooking of poultry is a gender based duty and has socio-cultural roles. Ethiopians are dependent on limited types of animals for meats due to the taboo associated culturally. Moreover, the consumption of meat and meat products has a very tidy association with religious beliefs, and are influenced by religions. The main religions of Ethiopia have their own peculiar doctrines of setting the feeding habits and customs of their followers. They influence meat products consumption through dictating the source animals that should be used or not be used for food, and scheduling the days of the years in periodical permeation and restriction of consumptions which in turn influences the pattern of meat consumption in the country. In Ethiopia, a cow or an ox is commonly butchered for the sole purpose of selling within the community. In special occasions, people have a cultural ceremony of slaughtering cow or ox and sharing among the group, called Kircha, which is a very common option of the people in rural area where access of meat is challenging frequently.

• Journal of Communications and Networks
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• v.18 no.4
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• pp.649-657
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• 2016

In this paper, we investigate energy efficiency (EE) of the traditional co-located and the distributed massive multiple-input multiple-output (MIMO) systems. First, we derive an approximate EE expression for both the idealistic and the realistic power consumption models. Then an optimal energy-efficient remote access unit (RAU) selection algorithm based on the distance between the mobile stations (MSs) and the RAUs are developed to maximize the EE for the downlink distributed massive MIMO systems under the realistic power consumption model. Numerical results show that the EE of the distributed massive MIMO systems is larger than the co-located massive MIMO systems under both the idealistic and realistic power consumption models, and the optimal EE can be obtained by the developed energy-efficient RAU selection algorithm.