SEONG CHO | Sungshin Women's University (original) (raw)
Papers by SEONG CHO
Wireless distributed microsensor systems will enable the reliable monitoring and control of a var... more Wireless distributed microsensor systems will enable the reliable monitoring and control of a variety of applications that range from medical and home security to machine diagnosis, chemical/biological detection and other military applications. The sensors have to be designed in a highly integrated fashion, optimizing across all levels of system abstraction, with the goal of minimizing energy dissipation. This paper addresses some of the key design considerations for future microsensor systems including the network protocols required for collaborative sensing and information distribution, system partitioning considering computation and communication costs, low energy electronics, power system design and energy harvesting techniques.
IEEE Transactions on Very Large Scale Integration Systems, 1999
Variable length coding is a widely used technique in digital video compression systems. Previous ... more Variable length coding is a widely used technique in digital video compression systems. Previous work related to variable length decoders (VLD's) are primarily aimed at high throughput applications, but the increased demand for portable multimedia systems has made power a very important factor. In this paper, a data-driven variable length decoding architecture is presented, which exploits the signal statistics of variable length codes to reduce power. The approach uses fine-grain lookup table (LUT) partitioning to reduce switched capacitance based on codeword frequency. The complete VLD for MPEG-2 has been fabricated and consumes 530 W at 1.35 V with a video rate of 48-M discrete cosine transform samples/s using a 0.6-m CMOS technology. More than an order of magnitude power reduction is demonstrated without performance loss compared to a conventional parallel decoding scheme with a single LUT.
Journal of Magnetism and Magnetic Materials, 2007
A thorough understanding of the magnetocaloric properties of existing magnetic refrigerant materi... more A thorough understanding of the magnetocaloric properties of existing magnetic refrigerant materials has been an important issue in magnetic refrigeration technology. This paper reviews a new class of magnetocaloric material, that is, the ferromagnetic perovskite manganites (R 1Àx M x MnO 3 , where R ¼ La, Nd, Pr and M ¼ Ca, Sr, Ba, etc.). The nature of these materials with respect to their magnetocaloric properties has been analyzed and discussed systematically. A comparison of the magnetocaloric effect of the manganites with other materials is given. The potential manganites are nominated for a variety of large-and small-scale magnetic refrigeration applications in the temperature range of 100-375 K. It is believed that the manganite materials with the superior magnetocaloric properties in addition to cheap materials-processing cost will be the option of future magnetic refrigeration technology. r
Journal of Vlsi Signal Processing Systems for Signal Image and Video Technology, 2004
In the past few years, wireless microsensor networks have attracted a great deal of attention in ... more In the past few years, wireless microsensor networks have attracted a great deal of attention in the research community. This is due to the applications that will be enabled once wireless microsensor networks are in place. The design of wireless microsensor networks, however, represents a difficult challenge. Since many applications require fault-tolerant, long-term sensing, one important challenge is to design sensor networks that have long system lifetimes. Achieving long system lifetimes is difficult because sensor nodes are severely energy-constrained. In this paper, we demonstrate system-level techniques that adapt and tradeoff software and hardware parameters in response to changes in the requirements of the user, the characteristics of the underlying hardware, and the properties of the environment. By using these power-aware, system-level techniques, we are able to reduce the energy consumption of both general, adaptable systems and dedicated point systems. Moreover, given a specific set of operating conditions for a particular system, we show how energy savings of 50% can be achieved.
ABSTRACT Wireless microsensor systems are used in a variety of civil and military applications. S... more ABSTRACT Wireless microsensor systems are used in a variety of civil and military applications. Such microsensors are required to operate for years from a small energy source. To minimize the energy dissipation of the sensor node, RF front-end cir-cuitry ...
Biochemical and Biophysical Research Communications, 2002
Dysregulation of matrix metalloproteinases (MMPs) and ineffective fibrinolysis are associated wit... more Dysregulation of matrix metalloproteinases (MMPs) and ineffective fibrinolysis are associated with the deposition of extracellular matrix (ECM). We hypothesized that elevated plasminogen activator inhibitor (PAI)-1 promotes ECM deposition in the asthmatic airway by inhibiting MMP-9 activity and fibrinolysis. Degree of airway inflammation was similar in PAI-1 À=À and wild type (WT) mice after ovalbumin (OVA) challenge. PAI-1 production, deposition of collagen and fibrin, and MMP-9 activity in the lung tissue or airways were greater after OVA challenge compared with saline challenge. However, in PAI-1 À=À mice, collagen deposition was 2-fold less, fibrin deposition was 4-fold less, and MMP-9 activity was 3-fold higher. This is the first direct evidence that the plasmin system regulates ECM deposition in the airways of a murine asthma model, independently of the effect of PAI-1 on inflammatory cells. The results suggest that the PAI-1-dependent inhibition of MMP-9 activity and fibrinolysis is a major mechanism by which ECM deposition occurs. Ó
Wireless distributed microsensor systems will enable the reliable monitoring and control of a var... more Wireless distributed microsensor systems will enable the reliable monitoring and control of a variety of applications that range from medical and home security to machine diagnosis, chemical/biological detection and other military applications. The sensors have to be designed in a highly integrated fashion, optimizing across all levels of system abstraction, with the goal of minimizing energy dissipation. This paper addresses some of the key design considerations for future microsensor systems including the network protocols required for collaborative sensing and information distribution, system partitioning considering computation and communication costs, low energy electronics, power system design and energy harvesting techniques.
IEEE Transactions on Very Large Scale Integration Systems, 1999
Variable length coding is a widely used technique in digital video compression systems. Previous ... more Variable length coding is a widely used technique in digital video compression systems. Previous work related to variable length decoders (VLD's) are primarily aimed at high throughput applications, but the increased demand for portable multimedia systems has made power a very important factor. In this paper, a data-driven variable length decoding architecture is presented, which exploits the signal statistics of variable length codes to reduce power. The approach uses fine-grain lookup table (LUT) partitioning to reduce switched capacitance based on codeword frequency. The complete VLD for MPEG-2 has been fabricated and consumes 530 W at 1.35 V with a video rate of 48-M discrete cosine transform samples/s using a 0.6-m CMOS technology. More than an order of magnitude power reduction is demonstrated without performance loss compared to a conventional parallel decoding scheme with a single LUT.
Journal of Magnetism and Magnetic Materials, 2007
A thorough understanding of the magnetocaloric properties of existing magnetic refrigerant materi... more A thorough understanding of the magnetocaloric properties of existing magnetic refrigerant materials has been an important issue in magnetic refrigeration technology. This paper reviews a new class of magnetocaloric material, that is, the ferromagnetic perovskite manganites (R 1Àx M x MnO 3 , where R ¼ La, Nd, Pr and M ¼ Ca, Sr, Ba, etc.). The nature of these materials with respect to their magnetocaloric properties has been analyzed and discussed systematically. A comparison of the magnetocaloric effect of the manganites with other materials is given. The potential manganites are nominated for a variety of large-and small-scale magnetic refrigeration applications in the temperature range of 100-375 K. It is believed that the manganite materials with the superior magnetocaloric properties in addition to cheap materials-processing cost will be the option of future magnetic refrigeration technology. r
Journal of Vlsi Signal Processing Systems for Signal Image and Video Technology, 2004
In the past few years, wireless microsensor networks have attracted a great deal of attention in ... more In the past few years, wireless microsensor networks have attracted a great deal of attention in the research community. This is due to the applications that will be enabled once wireless microsensor networks are in place. The design of wireless microsensor networks, however, represents a difficult challenge. Since many applications require fault-tolerant, long-term sensing, one important challenge is to design sensor networks that have long system lifetimes. Achieving long system lifetimes is difficult because sensor nodes are severely energy-constrained. In this paper, we demonstrate system-level techniques that adapt and tradeoff software and hardware parameters in response to changes in the requirements of the user, the characteristics of the underlying hardware, and the properties of the environment. By using these power-aware, system-level techniques, we are able to reduce the energy consumption of both general, adaptable systems and dedicated point systems. Moreover, given a specific set of operating conditions for a particular system, we show how energy savings of 50% can be achieved.
ABSTRACT Wireless microsensor systems are used in a variety of civil and military applications. S... more ABSTRACT Wireless microsensor systems are used in a variety of civil and military applications. Such microsensors are required to operate for years from a small energy source. To minimize the energy dissipation of the sensor node, RF front-end cir-cuitry ...
Biochemical and Biophysical Research Communications, 2002
Dysregulation of matrix metalloproteinases (MMPs) and ineffective fibrinolysis are associated wit... more Dysregulation of matrix metalloproteinases (MMPs) and ineffective fibrinolysis are associated with the deposition of extracellular matrix (ECM). We hypothesized that elevated plasminogen activator inhibitor (PAI)-1 promotes ECM deposition in the asthmatic airway by inhibiting MMP-9 activity and fibrinolysis. Degree of airway inflammation was similar in PAI-1 À=À and wild type (WT) mice after ovalbumin (OVA) challenge. PAI-1 production, deposition of collagen and fibrin, and MMP-9 activity in the lung tissue or airways were greater after OVA challenge compared with saline challenge. However, in PAI-1 À=À mice, collagen deposition was 2-fold less, fibrin deposition was 4-fold less, and MMP-9 activity was 3-fold higher. This is the first direct evidence that the plasmin system regulates ECM deposition in the airways of a murine asthma model, independently of the effect of PAI-1 on inflammatory cells. The results suggest that the PAI-1-dependent inhibition of MMP-9 activity and fibrinolysis is a major mechanism by which ECM deposition occurs. Ó