• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
• /
• pp.232-234
• /
• 2006

Diabetic neuropathy is one of the most common diabetic complications. In clinical practices, nerve conduction velocity (NCV) has been used as a standard method for diagnosing diabetic neuropathy. However, it applies maximum of 100mA electric stimulus to nerves causing stress and pain to patients. In this study. as a non-invasive method, $TcpO_2$ was utilized to investigate the difference and relationship between $TcpO_2$ and $SpO_2$ of normal and diabetic neuropathy subjects. In addition, a new method of diagnosing diabetic neuropathy using $TcpO_2$ is suggested. 50 normal subjects and 50 diabetic patients with neuropathy diagnosed by NCV participated in this study. Parameters used in this study were $TcpO_2,\;TcpCo_2$, and $SpO_2$. As a result of the $TcpO_2$ measurements, statistical significances were found from $TcpO_2$ of hands and feet from normal and patients group (p<0.01). $SpO_2$ measured from index finger of normal and patient groups showed no statistical significance (p>0.05). On the other hand, $SpO_2$ measured from great toes of normal and patient group showed statistical significance (p<0.01). Correlation coefficient between $SpO_2$ of finger and $TcpO_2$ of hand was 0.400 (p<0.01) and $SpO_2$ of toe and $TcpO_2$ of foot was 0.471 (p<0.01). Both correlation values were statistically significant. Sensitivities and specificities of the $TcpO_2$ method were found to be 66 % and 92 %, respectively. If suggested $TcpO_2$ method is used periodically. prevention and early diagnosis of diabetic neuropathy is possible.

• 한국세라믹학회지
• /
• 제30권11호
• /
• pp.905-910
• /
• 1993

$\alpha$-tricalcium phosphate($\alpha$-TCP) powders were synthesized and their hydration properties were investigated in Tris. solution. Two kinds of $\alpha$-TCP powder samples were prepared; the one is reaction product of CaHPO4.2H2O and CaCO3, and another is that of hydroxyapatite(HAp) and $\beta$-Ca2P2O7. They were satisfied with Ca/P mole ratio 1.5 and were heated at 150$0^{\circ}C$ for 5 hours. In the hydration of $\alpha$-TCP samples the powder which was synthesized from HAp and $\beta$-Ca2P2O7 was hydrated faster than that from CaHPO4.2H2O and CaCO3. The hydration reaction of $\alpha$-TCP powder transformed rapidly into HAp accompanying setting and hardening. It was realized that the hydration reaction of $\alpha$-TCP was due to the solution-precipitation mechanism and the hydrates from the reaction were Ca-deficient HAp having funtional group HPO42-.

• 전자공학회논문지SC
• /
• 제44권3호
• /
• pp.1-8
• /
• 2007

당뇨병성 신경병증은 당뇨병성 신증, 당뇨병성 망막병증과 함께 당뇨병의 가장 흔한 합병증 중의 하나로 임상에서는 신경전도검사(nerve conduction velocity: NCV)를 실시하여 신경병증의 유무를 진단한다. 그러나 신경전도검사는 피부에 직접적으로 최대 100mA의 전기자극을 가하므로 피검자가 놀라거나 고통을 호소하는 경우가 많다. 본 논문에서는 $TcpO_2$를 이용하여 비관혈적으로 신경병증이 있는 그룹과 정상인 그룹 간의 $TcpO_2$와 $SpO_2$의 차이를 확인하고, $TcpO_2$와 $SpO_2$가 어떠한 관계인지 살펴보았다. 또한 $TcpO_2$ 측정방법을 당뇨병성 신경병증의 새로운 조기 진단 방법으로 제안하고자 하였다. 실험은 정상인 50명과 NCV를 통해 신경병증으로 확진 받은 당뇨병 환자 50명을 대상으로 하였으며, 분석 파라미터는 $TcpO_2$, $TcpCO_2$, $SpO_2$이었다. 측정결과 $TcpO_2$는 정상인과 당뇨병성 신경병증 환자 그룹 간에 손과 발에서 모두 통계적으로 유의한 차이가 있었다(p<0.01). $SpO_2$는 검지에서는 정상인과 당뇨병성 신경병증 환자 간에 통계적으로 차이가 없었지만(p>0.05), 엄지발가락에서는 유의한 차이가 있었다(p<0.01). 손가락의 $SpO_2$와 손의 $TcpO_2$는 상관관계가 0.400(p<0.01), 발가락의 $SpO_2$와 발의 $TcpO_2$는 0.471(p<0.01)로 통계적으로 유의한 상관관계를 발견하였다. 정상인과 당뇨병성 신경병증 환자 그룹 간에 손과 발의 $TcpO_2$ 방법의 민감도는 66%, 특이도는 92%로 나타났다. 본 연구를 통해서 $TcpO_2$ 방법이 신경병증의 유무를 확인할 수 있는 사전검사 도구로 사용이 가능할 수 있으며, 주기적인 $TcpO_2$ 검사를 통해 혈관폐색과 신경병증을 조기에 발견할 수 있어 당뇨병으로 인한 혈관폐색과 신경병증을 조기에 진단 할 수 있는 유용한 방법이 될 것으로 사료된다.

• 한국인터넷방송통신학회논문지
• /
• 제17권2호
• /
• pp.119-126
• /
• 2017

TCP/IP 표준을 개발하는 IETF의 상위 기구인 IAB는 작은 사물에도 TCP/IP protocol stack을 붙이기로 결정했다. 이는 하나의 작은 사물도 하나의 통신 노드로 인정하여, 이를 다섯 개의 전 계층이 올라간 스마트 오브젝트로 확장하겠다는 상징적인 의미를 가진다. 이러한 배경 아래서 등장한 것이 웹을 기반으로 사물 간 지능적으로 네트워크를 구성해 통신하는 IoT/WoT이다. CoAP는 제한된 환경 내에서 사용할 수 있는 프로토콜로 사물이 인터넷에 연결될 것을 예상하여 만든 표준 규약이다. 이에 따라 본 논문에서는 CoAP 네트워크가 구축된 환경에서 CoAP와 연결되어 관련 사물들의 데이터를 수집하며 관리할 수 있는 Middleware API를 제안하고자 한다.

• 한국환경농학회지
• /
• 제34권4호
• /
• pp.345-349
• /
• 2015

BACKGROUND: In this study, we have attempted to identify a urinary biomarker to assess chlorpyrifos exposure in farmers. The major metabolite and the excretion pathway of chlorpyrifos is 3,5,6-trichloro-2-pyridinol (TCP) in urine. Herein, we describe an adequate synthetic method for TCP hapten for measuring urinary TCP of farmers. METHODS AND RESULTS: First, TCP was prepared by spacer attachment through hydrolysis of thiophosphate ester from chlorpyrifos. After reaction with benzyl bromide, the TCP was transformed into 2,3,5-trichloro-6-benzyloxypyridine. Next, the chlorine in the 2 ^nd position of the pyridyl ring was substituted into 3-mercaptopropanoic acid spacer arm. Finally, the phenyl group attached to the 6 ^th position in pyridyl ring was removed for producing the targeted product, 3-(3,5-Dichloro-6-hydroxy-2-pyridyl) thiopropanoic acid. CONCLUSION: Henceforth, this TCP hapten would be used in developing immunoassay studies for the detection and quantitation of urinary TCP of farmers.

• 한국재료학회지
• /
• 제16권1호
• /
• pp.1-4
• /
• 2006

Biodegradable $\beta$-tricalcium phosphate ( $\beta$-TCP)/poly(lactide-co-glycolide) (PLGA) composites were synthesized by in-situ polymerization with microwave energy. The influence of the $\beta$-TCP content in $\beta$-TCP/PLGA composites on the molecular weight, crystallinity, microstructure and mechanical properties was investigated. As the molecular weight of composites decreased, the $\beta$-TCP content increased up to 10 wt.%, while the excess addition of the $\beta$-TCP content above 10 wt.% the molecular weight increased with increasing of the $\beta$-TCP content. This behavior would be due to the superheating effect or nonthermal effect induced by microwave energy. It was found that the bending strength and Young's modulus of the $\beta$-TCP/PLGA composites was proportional to the molecular weight of PLGA. The bending strength of the $\beta$-TCP/PLGA composites ranged from 18 to 38 MPa, while Young's modulus was in the range from 2 to 6 GPa.

• 한국재료학회:학술대회논문집
• /
• 한국재료학회 2009년도 추계학술발표대회
• /
• pp.39.2-39.2
• /
• 2009

In this work, Poly($\varepsilon$-Caprolactone)(PCL) andpoly(3-hydroxybutyrate-co-3-hydroxyvalerate)(PHBV) mats were fabricated usingelectrospinning process. The electrospinning process is a simple and efficient method to fabricate the nanofibrous mats. PCL and PHBV is a kind of biodegradable polymer but their mechanical properties aren't good. For improving mechanical properties, PHBV mats were coated by TCP. Using PCL mats and TCP-coated PHBV composite mats, a bio-resorbablebone plate were made by pressing. Detailed micro-structural characterization was done by SEM techniques. Tensile strength and bending strength were also evaluated for mechanical properties. The cytotoxicity evaluation ofPCL/TCP-coated PHBV composite multilayer was done by MTT assay. The evidence obtained in this work implies the potential for use as a biodegradable boneplate.

• 한국세라믹학회지
• /
• 제50권4호
• /
• pp.275-279
• /
• 2013

The purpose of this study was to prepare calcium phosphate cement [CPC] for use in artificial bone. Nano-crystalline calcium phosphate [CaP] was precipitated at $37^{\circ}C$ using highly active $Ca(OH)_2$ in DI water and an aqueous solution of $H_3PO_4$. From the XRD measurements, the nano-CaP powder was close to apatitic TCP phase and the powders fired at $800^{\circ}C$ showed a critical ${\beta}$-TCP phase. A mixture of one mole $CaCO_3$ and two moles di-calcium phosphate was calcined at $1100^{\circ}C$ to make a reference ${\beta}$-TCP material. The nano-CaP powders were added to the normal ${\beta}$-TCP matrix and fired at $900^{\circ}C$ to make a ${\beta}$-TCP block. The sintered block showed improved mechanical strength, which was caused by the solid state interaction between nano-CaP and normal ${\beta}$-TCP.

• Journal of Communications and Networks
• /
• 제13권3호
• /
• pp.277-285
• /
• 2011

Real-time multimedia streaming over the Internet is rapidly increasing with the popularity of user-created contents, Web 2.0 trends, and P2P (peer-to-peer) delivery support. While many homes today are broadband-enabled, the quality of experience (QoE) of a user is still limited due to frequent interruption of media playout. The vulnerability of TCP (transmission control protocol), the popular transport-layer protocol for streaming in practice, to the packet losses, retransmissions, and timeouts makes it hard to deliver a timely and persistent flow of packets for online multimedia contents. This paper presents TCP-real-time online multimedia environment (ROME), a novel transport-layer framework that allows the establishment and coordination of multiple many-to-one TCP connections. Between one client with multiple home addresses and multiple co-located or distributed servers, TCP-ROME increases the total throughput by aggregating the resources of multiple TCP connections. It also overcomes the bandwidth fluctuations of network bottlenecks by dynamically coordinating the streams of contents from multiple servers and by adapting the streaming rate of all connections to match the bandwidth requirement of the target video.

• 한국재료학회지
• /
• 제16권11호
• /
• pp.676-680
• /
• 2006

The biodegradable $\beta$-tricalcium phosphate ($\beta$-TCP)/poly(lactide-co-glycolide) (PLGA) composites were synthesized by in situ polymerization with microwave energy. The degradation behavior of $\beta$-TCP/PLGA composite was investigated by soaking in simulated body fluid (SBF) for 4 weeks. The molecular weight of the $\beta$-TCP/PLGA composites decreased with soaking time until week 2, whereas the loss rate of molecular weight reduced after week 2. The incubation time was needed for the degradation of the $\beta$-TCP, indicating that the $\beta$-TCP should be detached from the PLGA matrix and then degraded into SBF solution. The studies of mass loss of the composites with the soaking time revealed that the degradation behavior of PLGA would be processed with the transformation from the polymer to the oligomer followed by the degradation. Morphological changes, whisker-like, due to transformation and degradation of polymer in the composites were observed after week 2. On the basis of the results, it found that the degradation behavior of $\beta$-TCP/PLGA composites was influenced by the $\beta$-TCP content in the composites and the degradation rate of the composites could be controlled by the initial molecular weight of PLGA in the composites.