A narrow loop noise bandwidth method is desirable to reduce the error of raw measurements due to the thermal noise. However, it degrades the performance of GPS initial synchronization such as mean acquisition time. And it restricts the loop noise bandwidth to a fixed value determined by the lower bound of the allowable range of carrier-to-noise power ratio, so that it is difficult to optimally track GPS signal. In order to make up for the weak points of the fixed-type narrow loop noise bandwidth method and simultaneously minimize the error of code and carrier measurements, this paper proposes a stepwise-type adaptive bandwidth algorithm for DGPS reference receivers. In this paper, it is shown that the proposed adaptive bandwidth algorithm can provide more accurate measurements than those of the fixed-type narrow loop noise bandwidth method, in view of analyzing the simulation results between two signal tracking algorithms. This paper also carries out sensitivity analysis of the proposed adaptive bandwidth algorithm due to the estimation uncertainty of carrier-to-noise power ratio. Finally the analysis results are verified by the experiment using GPS simulator.
Wnt 신호 전달 과정은 다세포 생물체의 발생 과정에서 세포의 증식이나 분화를 조절하거나 성인 조직에서 항상성을 유지하는데 결정적인 역할을 한다. 따라서 Wnt 신호 전달의 조절에 이상이 생기면 암을 비롯한 다양한 질병이 유발되어진다. 최근 들어서 Wnt 신호 전달의 이상에 의해 유도될 것이라고 생각되어지는 질병의 수가 많아져서, Wnt 신호 전달의 조절에 관심을 갖는 연구자가 많아지고 있다. 많은 리뷰 논문이 출판되었지만, 대부분의 경우 Wnt 전문가
본 논문에서는 인천항의 장래 입 출항 교통량을 추정하고, 인천 조류신호소에서 제공하는 조류정보의 가치를 분석하였다. 전국항만 기본계획에 따르면 인천항의 2020년 물동량은 2005년 대비 약 2배로 증가한다. 이에 따라 해상 교통량도 크게 증가할 것이다. 또한 인천항을 통항하는 선박의 조류영향으로 인한 해양사고를 방지하기 위하여 해양수산부는 조류신호소를 운영하고 있다. 그러나 이의 가치에 대한 분석이 없어 그 효과가 정량적으로 알려진 것이 없다. 따라서 본 연구에서는 인천 조류선호소의 정보에 대한 가치를 조건부 가치측정법(CVM)으로 산출하고, 장래 교통량을 고려한 정보가치를 분석하였다. 이로써 조류정보를 직접 이용하는 교통량을 고려한 연간 정보가치는 2000년부터 2020년까지 대략 1.7~2.8억원이 되는 것으로 추산되었다.
A unique technique to extract the phase in time domain is proposed in order to measure the time parameters such as speed and depth by transmitting sound and electric waves. In the signal analysis processing, the phase of pulse signal can be transformed and digitalized with local data in real time without the effect of direct current bias and Nyquist limits. This method is sensitive to base frequency of pulse signal with high spacial resolution and is effective to compare two signals which have different forms. It is expected that the phase analysis technique will be applied to the measurement of the speed and depth accurately by ultrasonic pulse signal in water.
대형여객선을 제외한 대부분의 선박에서는 정확하게 환자를 진단하고 치료할 수 있는 전문의가 없기 때문에 의료환경이 매우 열악하다. 따라서 선원에 대한 복지 및 근무환경의 개선이라는 차원에서 선택용 원적진료가 절실하고, 근무당사자 및 노조의 관심도 높아지고 있다. 본 연구는 원앙 및 연안항해에 종사하는 선박에서 환자 진료 시 중요한 정보로 활용되는 심전도와 청진음을 용이하게 측정하여 육상의 전문의사에게 전송함으로써 원격으로 진료를 수행할 수 있는 시스템을 개발하고자 하는 것이다. 본 논문에서는 기개발한 PC 기반의 디지털 심전도 및 청진기를 통하여 측정된 데이터를 국제해사위성(INMARSAT)을 이용하여 전송할 수 있는 시스템을 설계하였고, 실험을 통하여 전송 전후의 신호를 비교하여 데이터 오류를 검정하였다. 그리고 선박 통신시스템을 이용한 선박 원격의료가 가능함을 확인하였다.
The problem for parameters estimation of the received signals impinging on array sensors has long been of great research Interest in a great variety of applications, such as radar, sonar, and land mobile communications systems. Conventional subspace-based algorithms, such as MUSIC and ESPRIT, require an extensive computation of inverse matrix and eigen-decomposition In this paper, we propose a new parameters estimation algorithm via nonlinear minimization, which is simplified computationally and estimates signal parameters simultaneously.
The lutropin/choriogonadotropin receptor (LHR) is a member of the rhodopsin-like subfamily of G protein coupled receptor (GPCRs), that has been shown to mediate the internalization of its two naturally occurring agonist, lutropin and choriogonadotropin (CG). The clustered agonist-receptor complex is internalized by a dynamin-dependent pathway and traverses the endosomal compartment without agonist dissociation Dissociation of the agonist-receptor complex occurs in the lysosomes, where both the agonist and receptor are degrade. Recently, constitutively activating mutations of the receptor have been identified that are associated with familial male-precocious puberty (FMPP). A FMPP is a form of sexual precocious puberty in boys in which testosterone levels are elevated independent of changes in luteinizing hormone-releasing hormone and serum luteinizing hormone levels, We have now analyzed two naturally occurring, constitutively active mutants of the human LHR. These mutations were introduced into the rat LHR (rLHR) and are designated L435R and D556Y. Cells expressing rLHR-D556Y bind human choriogonadotropin (hCG) with normal affinity, exhibit a 25-fold increase in basal cAMP and respond to hCG with a normal increase in cAMP accumulation. Cells expressing rLHR-L435R also bind hCG with normal affinity, exhibit a 47-fold increase in basal cAMP, and do not respond to hCG with a further increase in cAMP accumulation. This mutation enhances the internalization of the free and agonist-occupied receptors ~2- and ~17- fold, respectively We conclude that the state of activation of the rLHR can modulate its basal and/or agonist-stimulated internalization. Since the internalization of hCG is involved in the termination of hCG actions, we suggest that the lack of responsiveness detected in cells expressing rLHR-L435R is due to the fast rate of internalization of the bound hCG. The finding that membranes expressing rLHR-L435R respond to hCG with an increase in adenylyl cyclase activity supports this suggestion. Autonomous Leydig cell activity in FMPP is caused by a constitutively activating LH/CGR.
본 논문에서는 IMT-2000 기지국용 30 W 전력증폭기를 구현하고 전파흡수제를 사용하여 발진과 상호간섭에 의한 신호의 왜곡을 제거하므로써 이득평탄도 및 상호 변조 왜곡을 개선하였다. 사용된 전파흡수체의 흡수능은 3.6 GHz 대역에서 -10 dB이하, 2.3 GHz 대역에서 -4 dB 이하가 측정되었다. 기존의 전력증폭기의 특성을 측정한 결과 이득은 57.37 dB(측정시 40 dB 감쇠기 부가)이상, 이득평탄도는 ±0.33 dB였으며, 출력의 세기가 33.3 W일 때 IMD 특성은 27 dBc 로 나타났다. 한편 전력증폭기의 최종단인 고출력 전력결합기 부분에 전파흡수체를 부착한 후의 이득은 약 58.43 dB(측정시 40 dB 감쇠기 부가)이상, 이득평탄도는 ±0.0935 dB 가 나타났으며, 출력이 33.3 W 일 때 3차 IMD 성분은 약 29 dBc 였다. 측정 결과 전파흡수체를 사용하였을 경우와 사용하지 않았을 경우 이득은 1 dB, 이득평탄도는 0.3 dB, IMD 특성은 1.77 dBc 가 각각 개선됨을 확인하였다.
This paper deals with the development of RACOM(Radar Signal Detecting & Processing Computer). RACOM is a radar display system specially designed for radar scan conversion, signal processing and PCI radar image display. RACOM contains two components; i )RSP(Radar Signal Processor) board which is a PCI based board for receiving video, trigger, heading & bearing signals from radar scanner & tranceiver units and processing these signals to generate high resolution radar image, and ⅱ)Applications which perform ordinary radar display functions such as EBL, VRM and so on. Since RACOM is designed to meet a wide variety of specifications(type of output signal from tranceiver unit), to record radar images and to distribute those images in real time to everywhere in a networked environment, it can be applicable to AIS(Automatic Identification System) and VDR(Voyage Data Recorder).
Before some experiments were carried out with analog bandpass filter which used for filtering the noise included in sound source signal. And this filter was constituted by condenser, register and operational amplifier. Hut these elements made the phase characteristics to differentiate in each sensing channel and cause a little of measurement error. We made new measurement system that was substituted digital filter for the analog filter in order to develop the optimal system which could find the time delay between each sensors with high accuracy. This paper describes the new system's constitution and the function of each parts. Specially three digital filters were designed and applied to the digital signal processing Part. And a series of experiments were carried out with the source's distance 9.53meters and the random bearing interval within the limits of 0˚ ~ 180˚. As a result, we have recognized that the accuracy of measurements were differentiated by the methods what kind of digital filter were adopted. And we have confirmed the facts that IIR LPF was suitable for sound source's bearing measurement and FIR LPF reduced the range measurement error.