• 융합신호처리학회논문지
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• 제9권1호
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• pp.62-74
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• 2008

본 논문에서는 전파천문용으로 사용하기 위한 대칭형 디지털 필터 코어의 설계를 제안한다. 본 논문에서는 Xilinx사의 Virtex-4 SX55 모델의 FPGA칩을 기반으로 한국우주전파관측망(Korean VLBI Network; KVN)의 자료획득시스템에서 요구하는 FIR 필터 코어의 기능을 VHDL 코드로 설계하였다. 본 논문에서 설계한 디지털 필터는 디지털 필터계수를 공유하여 시스템의 효율을 증대시킨 대칭형 구조(Symmetric Structure)를 갖는다. 대칭구조의 디지털 필터(Symmetric FIR Filter Unit; SFFU)는 제한된 시스템 클록을 이용하여 데이터의 처리를 효과적으로 수행하기 위해 병렬처리 방법을 사용한다. 따라서 본 논문에서는 SFFU의 효율적인 설계를 위해 전체적인 IP core의 합성 및 실험에는 통합 합성 소프트웨어 ISE Foundation을 사용하였으며, GUI 환경이 뛰어난 core generator를 활용하였다. 설계한 디지털 필터 코어의 합성 결과, 최대 동작 주파수는 260MHz를 약간 상회하는 수준까지 달성하였으며, 슬라이스, LUT 등의 리소스 사용량은 40% 이하임을 확인하였다 또한 Mentor Graphics사의 Modelsim 6.la 버전을 이용하여 SFFU(Symmetric FIR Filter Unit)의 시뮬레이션을 수행한 결과, 오류 없이 작동하는 것을 확인하였다. SFFU의 기능을 확인하기 위하여 추가적으로 Matlab을 이용하여 의사 신호를 이용한 시뮬레이션을 수행하였다. 시뮬레이션과 설계한 디지털 FIR 필터의 비교실험결과에서 FIR 필터의 기능을 수행하고 있음을 확인할 수 있어 본 논문에서 FPGA와 VHDL을 이용하여 설계한 대칭구조의 디지털 FIR 필터의 유효성을 확인할 수 있었다.

• 한국환경복원기술학회지
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• 제16권5호
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• pp.49-57
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• 2013

This study was carried out to analysis change of distribution and habitat location environment of Korean Fir which is typically vulnerable species by the climate change in Mt. Jiri and Halla. Korean Fir was decreased 18% during 27 year since year 1981, Mt. Halla was 34% during 15 years since year 1988. In the same periods, Temperature change was increased from 8.56 to $9.36^{\circ}C$, from 11.2 to $12.1^{\circ}C$. Distribution changes by the elevation showed higher change ratio 1,400~1,600m in Mt. Jiri and 1,200~1,900m in Mt. Halla. Changes of Korean Fir each slope aspects was high $180{\sim}360^{\circ}$ in Mt. Jiri, $45^{\circ}$ in Mt. Halla. In slope was $30^{\circ}$ in Mt. Jiri and $20^{\circ}$ in Mt. Halla. Changes by reliefs was 12 in Mt. Jiri, 0 or 15 in Mt. Halla, and Sites of Korean Fir was convex slopes both of two areas. Changes by soils was in the good drainage textures.

• 전자공학회논문지B
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• 제31B권9호
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• pp.22-26
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• 1994

In this paper a method of designing FIR filters without digital arithmetic operationsi is persented. The filter coefficients are represented by resistors combined with a differential amplifier. With this method an FIR filter can be simply impemented without refering to complex digital arithmetic operations. Furthermore, in this scheme, no additional D/A converter is needed for D/A conversion. Spectral response response of a pulse shaping filter of 17 coefficients is shown as an illustration.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
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• pp.567-570
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• 1988

This paper describes the design of FIR filtering DSP-chip that can be operated without programming. The proposed DSP-chip has not only the improvement of execution time but also selectivity of filter length from N=1 to N=128. Hilbert Transformer can be designed from this chip. FIR filter system is composed of Data memory/Control Unit, external memory and multiplier-accumulator. Data memory/Control Unit is laid out in this paper.

• 음성과학
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• 제5권1호
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• pp.81-88
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• 1999

This paper provides a method for speech detection. After first order FIR filtering on the speech signals, we applied the conventional method of endpoint detection which utilizes the energy as the criterion in separating signals from background noise. By FIR filtering, only the Fourier components with large values of [amplitude x frequency] become significant in energy profile. By applying this procedure to the 445-words database constructed from ETRI, we confirmed that the low-amplitude noise and/or the low-frequency noise are separated clearly from the speech signals, thereby enhancing the feasibility of ideal endpoint detections.

• 전자공학회논문지D
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• 제36D권1호
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• pp.63-73
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• 1999

본 논문에서는 저전력/고속 디지털 FIR 필터를 위한 새로운 파이프라인 구조를 제안한다. 제안된 파이프 라인 구조는 입력 데이터와 계수간 곱셈의 일부를 입력 지연단에서 수행하도록 하는 리타이밍 기법을 사용하여 속도를 향상시켰으며 공급전압을 낮추는 방법을 병행하여 전력을 감소시켰다. 제안된 파이프라인 구조를 적용하여 PRML 디스크 드라이브용 8 탭 FIR 필터를 설계하고 0.8${\mu}m$ CMOS 공정을 이용하여 제작하였다. 실험결과 설계된 FIR 필터는 3.3.V에서 최대 192 MHz까지 동작하였으며 이 때 1.22 mW/MHz의 전력을 소모하였다. 결과적으로 제안된 구조의 FIR 필터는 기존의 구조에 비해 약 16%의 속도가 향상되었으며 같은 데이터 처리능력을 가질 때 약 23%의 전력 감소 효과를 갖는다.

• 환경생물
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• 제25권2호
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• pp.158-167
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• 2007

내설악 전나무림 현황을 조사하고 이를 통하여 산림 생태계 이해방식을 비판적으로 고찰하였다. 조사는 1996년부터 2006년까지 수행된 것으로 일종의 중간보고서로 작성하였다. 임분의 수직구조 위주로 조사하였으며 비록 내설악 전나무림에 한정된 것이기는 하나 고전 천이론 보다는 Stand dynamic이 산림생태계를 설명하는데 적합하다는 것을 확인할 수 있었다.

• 정신신체의학
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• 제31권2호
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• pp.149-154
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• 2023

Objectives : Far-infrared (FIR) lights have been investigated for sleep quality intervention. We sought to measure the advantageous effects of FIR in sleep using polysomnographic data as the objective outcomes. Methods : The ten healthy volunteers were enrolled in a single-center, prospective, patient-blind, single-arm trial. Individuals slept on a sham mattress and a FIR emitting mattress with polysomnography for one night each. Results : Sleep efficiency showed an increasing trend but was not statistically significant. PSQI-K significantly decreased (p=0.013). The latency to REM of the baseline was shorter than that of the intervention (p=0.008). Though there was no statistical significance, Stage N1 and N2 were shortened, and Stage N3 was prolonged after the intervention compared to the baseline. Conclusions : The FIR-emitting mattresses improved sleep quality on self-reported insomnia. We suggested the candidate for the markers altered by the FIR therapy, such as the normalization of REM latency and increased N3 sleep.

• 한국연소학회지
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• 제21권1호
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• pp.38-45
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• 2016

Flame characteristics and NO emission behavior in $CH_4$/air-air premixed counterflow flames with applying FIR and FGR with $CO_2$ and $H_2O$ were investigated numerically by varying the ratios of FIR and FGR as well as global strain rate. Chemical effects of added $CO_2$ and $H_2O$ via FIR and FGR were analyzed through comparing flame characteristics and NO behaviors from real species($CO_2$ and $H_2O$) with those from their artificial species($XCO_2$ and $XH_2O$) which have the same thermochemical, radiative, and transport properties to those for the real species. The results showed that flame temperature and NO emission with FIR varied much more sensitively than that with FGR. Those varied little irrespective of adding $CO_2$, $H_2O$, and their artificial species to the fuel stream via FIR. However, Those were varied complicatedly by chemical effects of added $CO_2$ and $H_2O$ via FGR. Detailed analyses for them were made and discussed.

• The Korean Journal of Physiology and Pharmacology
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• 제23권2호
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• pp.141-150
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• 2019

Despite increased evidence of bio-activity following far-infrared (FIR) radiation, susceptibility of cell signaling to FIR radiation-induced homeostasis is poorly understood. To observe the effects of FIR radiation, FIR-radiated materials-coated fabric was put on experimental rats or applied to L6 cells, and microarray analysis, quantitative real-time polymerase chain reaction, and wound healing assays were performed. Microarray analysis revealed that messenger RNA expressions of rat muscle were stimulated by FIR radiation in a dose-dependent manner in amount of 10% and 30% materials-coated. In 30% group, 1,473 differentially expressed genes were identified (fold change [FC] > 1.5), and 218 genes were significantly regulated (FC > 1.5 and p < 0.05). Microarray analysis showed that extracellular matrix (ECM)-receptor interaction, focal adhesion, and cell migration-related pathways were significantly stimulated in rat muscle. ECM and platelet-derived growth factor (PDGF)-mediated cell migration-related genes were increased. And, results showed that the relative gene expression of actin beta was increased. FIR radiation also stimulated actin subunit and actin-related genes. We observed that wound healing was certainly promoted by FIR radiation over 48 h in L6 cells. Therefore, we suggest that FIR radiation can penetrate the body and stimulate PDGF-mediated cell migration through ECM-integrin signaling in rats.