• Investigative Magnetic Resonance Imaging
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• v.22 no.1
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• pp.26-36
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• 2018

Purpose: Children born with single ventricle physiology demonstrate poor growth rate and suffer from malnutrition, which lead to increased morbidity and mortality in this population. We assume that an anabolic steroid, oxandrolone, will promote growth in these infants by improving myocardial energy utilization. The purpose of this paper is to study the efficacy of oxandrolone on myocardial energy consumption in these infants. Materials and Methods: We modeled single ventricle physiology in a lamb by prenatally shunting the aorta to the pulmonary artery and then postnatally, we monitored cardiac energy utilization by quantitatively measuring the first order reaction rate constant, $k_f$ of the creatine-kinase reaction in the heart using magnetization transfer $^{31}P$ magnetic resonance spectroscopy, home built $^1H/^{31}P$ transmit/receive double tuned coil, and transmit/receive switch. We also performed cine MRI to study the structure and dynamic function of the myocardium and the left ventricular chamber. The spectroscopy data were processed using home-developed python software, while cine data were analyzed using Argus software. Results: We quantitatively measured both the first order reaction rate constant and ejection fraction in the control, shunted, and the oxandrolone-treated lambs. Both $k_f$ and ejection fraction were found to be more significantly reduced in the shunted lambs compared to the control lambs, and they are increased in oxandrolone-treated lambs. Conclusion: Some improvement was observed in both the first order reaction rate constant and ejection fraction for the lamb treated with oxandrolone in our preliminary study.

• Journal of Digital Convergence
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• v.18 no.10
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• pp.547-555
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• 2020

To investigate the effects of self-management programs for chronic low back pain (LBP), 63 subjects were assigned to three groups; self-exercise group (SEG), hot pack and low-frequency electrical stimulation group (HEG), and thermo-massage group (TMG). Parameters were the pain numeric rating scale (PNRS), Oswestry Disability Index (ODI), Roland Morris Disability Questionnaire (RMDQ) and Relapse frequency (RF). PNRS, ODI and RMDQ of SEG and TMG sustained effectiveness, however, PNRS, which improved after treatment in HEG, worsened in 6 month. Between the groups, all parameters were better in SEG and TMG compare to HEG. Exercise and thermo-massage can be considered as useful self-management performed at home to prevent the relapse of chronic LBP.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.3
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• pp.880-890
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• 2010

The intrasvascular ultrasound (IVUS) imaging technique is used to diagnose cerebrovascular diseases such as stroke. Recently, elasticity imaging methods have been investigated to diagnose blood clots attached to blood vessel intima. However, the IVUS imaging technique is an invasive method that requires a transducer to be inserted into blood vessel. In this paper, strain images are obtained of blood clots attached to blood vessel intima with data acquired from outside the blood vessel using a linear array transducer. In order to measure the displacement of blood vessel accurately, experimental data are acquired by steering ultrasound beams so that they can intersect the blood vessel wall at right angles. The acquired rf data are demodulated to the baseband. The resulting complex baseband signals are then processed by an autocorrelation algorithm to compute the blood vessel movement and thereby produce strain image. This proposed method is verified by experiments on a plastic blood vessel mimicking phantom. The efficacy of the proposed method was verified using a home-made blood vessel mimicking phantom. The blood vessel mimicking phantom was constructed by making a 6 mm diameter hollow cylinder inside it to simulate a blood vessel and adhering 2 mm thick soft plaque to the inner wall of the hollow cylinder. The RF data were acquired using a clinical ultrasound scanner (Accuvix XQ, Medison, Seoul. Korea) with a 7.5 MHz linear array transducer by steering ultrasound beams in steps of $1^{\circ}$ from $-40^{\circ}$ to $40^{\circ}$ for a total of 81 angles. Experimental results show that the plaque region near the blood vessel wall is softer than background tissue. Although the imaging region is restricted due to the limited range of angles for which scan lines are perpendicular to the wall, the feasibility of strain imaging is demonstrated.

• Journal of Adhesion and Interface
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• v.11 no.4
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• pp.137-143
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• 2010

Glass beads (GBs) were modified via plasma polymerization coatings in order to enhance the adsorption of polycyclic aromatic hydrocarbons (PAHs) in cigarette smoke and activated carbons (ACs) were also utilized for comparative purposes. First, GBs and ACs were subjected to surface modification via plasma polymerization coating of acrylic acid, acrylonitrile, 1,3-diaminopropane, thiophene or dimethylphosphite with a RF plasma (13.56 MHz) generator. Next, their adsorption behavior was evaluated with a home-made 4-port smoking machine by collecting the total particulate matters (TPMs) on a Cambridge filter pad, followed by the separation of PAHs via solid phase extraction and analysis with GC/MS. Finally, the plasma polymerization coatings were analyzed by FT-IR/ATR to elucidate the adsorption mechanism, while the topology of the modified GBs and ACs were studied by FE-SEM.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.05a
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• pp.387-390
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• 2006

TinyOS 기반 무선 센서 노드를 사용한 실시간 계측 데이터 측정 및 제어 기술은 특히 홈 네트워크 분야에 널리 적용되고 있다. 본 논문에서는 ATMegal128L을 장착한 최소 8대 이상의 Micaz Mote 센서 노드 모듈을 사용하여 각 방의 노도 값을 실시간 측정하는 시스템을 구현하였다. 특히 TinyOS에서 제공되는 OscilloscopeRF의 메시지 구조를 분석하여, 각 노드의 ID 및 계측 데이터를 추출하였다. 또한 이렇게 추출된 계측 데이터를 센서 네트워크의 싱크 노드로부터 데이터 통제 센터(Doc)로 효율적으로 전송하기 위한 TCP 기반 네트워크 프로그래밍을 구현하였다. 실험 결과 센서 노드 수 및 샘플링 주기에 상관없이 안정적으로 계측 데이터 수신이 이루어짐을 확인하였다. 한편, IEEE802.11a/g 기반 무선 네트워크를 통해 실시간 계측 상황을 휴대용 단말기인 PDA에서 확인할 수 있도록 이를 구현하였다.

• Journal of Korea Society of Industrial Information Systems
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• v.9 no.2
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• pp.89-95
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• 2004

CDMA is the way that more than one users can share the time and frequency at the same time and connect with multiple access in mobile communication. Multiple Access is indispensible for mobile communication because the limited frequency is able to be used by many users in mobile communication. CDMA is also applied to home network, military, business and medical sectors. This paper, presents a users should share limited frequency resource. CDMA module implemented with 8-layer PCB which consists of the Slice-board circuit, keeping Radio frequency characteristics and a slot type connector.

• Journal of information and communication convergence engineering
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• v.5 no.4
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• pp.382-388
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• 2007

Indoor location system using wireless sensor network technology was applied for the status evaluation and activity monitoring of elderly person or chronic invalid at home. Location awareness application is transparent to the daily activities, while providing the embedded computing infrastructure with an awareness of what is happening in this space. To locate an object, the active ceiling-mounted reference beacons were placed throughout the building. Reference beacons periodically publish location information on RF and ultrasonic signals to allow application running on mobile or static nodes to study and determine their physical location. Once object-carried passive listener receives the information, it subsequently determines it's location from reference beacons. By using only the sensor nodes without any external network infrastructure the cost of the system was reduced while the accuracy in our experiments. was fairly good and fine grained between 7 and 15 cm for location awareness in indoor environments. Passive architecture used here provides the security of the user privacy while at the server the privacy was secured by providing the authentication using Geopriv approach. This information from sensor nodes is further forwarded to base station where further computation is performed to determine the current position of object and several applications are enabled for context awareness.

• Applied Biological Chemistry
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• v.16 no.2
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• pp.53-59
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• 1973

The anthocyanins in Santa rosa plum (widely growing var. in Korea) were extracted with 0.5% methanolic HCl and purified with Amberlite IRC-50 cation exchange resin. The individual pigments were separated by paper chromatography. The two pigments were identified as cyanidin-3-monoglucoside and cyanidin-3-xyloglucoside based on the following evidence: Rf values in various solvents, partical acid hydrolysis, stepwise hydrolysis, sugar moiety, alkaline degradation, and absorption spectra in the visible region. Cyanicin-3-monoglucoside was the abundant pigment of the plum.

• Journal of the Institute of Convergence Signal Processing
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• v.9 no.1
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• pp.46-53
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• 2008

This paper presents a 13.56 MHz RFID reader that can be used as a door-lock system for smart home security. The RFID reader consists of a transmitter, a receiver, and a data processing block. To verify the operation of the developed RFID reader, we present both a PSPICE simulation for transmitter/receiver and a digital simulation for data processing block. In particular, a CRC block for error detection of received data and a Manchester decoding block for position detection of collided data are designed using VHDL. In addition, we applied a binary search algorithm for multi-tag anti-collision. The anti-collision procedure is carried out by PIC microcontroller on software. The experimental results show that the developed reader can provide the right multi-tag recognition.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.327-332
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• 2017

As Internet of Things (IoT) technology advances, there is a growing demand for location-based services (LBSs) to identify users' mobility and identity. The initial LBS system was mainly used to measure position information by measuring the phase of a signal transmitted from a global positioning system (GPS) satellite or by measuring distance to a satellite by tracking the code of a carrier signal. However, the use of GPS satellites is ineffective, because it is difficult to receive satellite signals indoors. Therefore, research on wireless communications systems like ultra-wide band (UWB), radio frequency identification (RFID), and ZigBee are being actively pursued for location recognition technology that can be utilized in an indoor environment. In this paper, we propose an LBS system that includes the 2.45GHz band for chirp spread spectrum (CSS), and the 3.1-10.6GHz band and the 250-750MHz bands for UWB using the IEEE 802.15.4a standard for low power-based location recognition. As a result, we confirmed that the 2.45GHz Industrial, Scientific and Medical (ISM) band RF transceiver and the ranging function can be realized in the hardware and has 0dBm output power.