Earticle

돼지의 성 판별을 위해서 중합효소연쇄반응(PCR) 기법을 시험하였다. SRY는 Y 염색체 상에 암호화되어 있으며 일차적인 웅성 발생에 대한 핵심적인 역할을 수행한다. Zinc finger X-Y(ZFX-ZFY) 유전자는 X-Y 염색체에 상동으로 존재하는 유전자들 중 하나이다. 본 연구진은 SRY 유전자와 ZFX-ZFY 유전자들의 증폭 양상을 이용하여 분자적 성 판별을 수행하였다. 가축돼지 품종들과 재래돼지의 정액과 모근을 포함한 여러 조직으로부터 추출한 genomic DNA들을 PCR assay에 이용하였다. SRY에 대한 증폭산물은 수컷에서만 특이적으로 관찰되었고, 암컷에서는 전혀 관찰되지 않았다. 반면, ZF 유전자에 대한 PCR 증폭 결과는 X, Y 염색체 간 유전자 길이의 다형성에 의한 이형성을 반영하는 두 가지 다른 양상의 밴드들로 관찰되었다. 이 둘 중 모든 개체에서 공통으로 발견되는 밴드는 X 염색체상의 ZFX를 주형으로 증폭된 것이며, 다른 하나는 수컷 특이적이며 ZFY 유전자를 주형으로 하는 것이다. PCR assay의 결과는 표현형에서 나타내는 성 판별 결과와 동일한 결과를 나타내었다. 본 연구결과는 Y 염색체 특이적인 SRY와 X, Y 염색체의 이형성을 나타내는 ZFX-ZFY에 대한 PCR 전략은 성을 판별하는 신속하면서도 정확한 실험기법으로 암수를 식별하는데 효율적으로 이용될 뿐만 아니라, 발생 중인 배의 할구나 정액, 모근같이 적은 양의 시료에도 활용할 수 있을 것으로 기대된다.

A method for sex determination of pigs was examined using polymerase chain reaction(PCR). Sex determining region Y(SRY) gene encoded on Y chromosome plays a key role for primary male development. Zinc finger X-Y(ZFX-ZFY) gene, one of the X-Y homology gene group was found on the X and Y chromosomes, respectively. We tested for molecular sexing by amplification patterns of SRY and ZF genes. Genomic DNAs from various resources including porcine hairs and semen collected from domestic pig breeds and native pigs was used for PCR assay of each gene. The amplified products for porcine SRY gene were yielded only in males but not in females. On the other hand, two differential patterns were observed in amplification of ZF gene reflecting the chromosomal dimorphism by a length polymorphism between X and Y chromosomes. Of both, a common band was detected in all individuals tested so that this band might be amplified from ZFX gene as a PCR template, but another is specific for males indicated that from ZFY. The result of PCR assay provides identical information to that from investigation of phenotypic genders of the pigs tested. We suggest that this PCR strategy to determine porcine sexes using comparison of the amplification patterns of the SRY gene specific for Y chromosome and the dimorphic ZF gene between X and Y chromosomes may be a rapid and precise method for discrimination of two sexes and applied to DNA analysis of small samples such as embryonic blastomere, semen, and hairs.

In this paper, two novel dynamic transmit antenna shuffling schemes, namely ‘Optimal’ and ‘Max STBC’, are presented in order to reduce the interference in V-BLAST/STBC scheme. These antenna shuffling schemes with the channel state information (CSI) from the receiver, which significantly improves performance of the Multiple-Input Multiple-Output (MIMO) system in Rayleigh flat-fading channels by selecting the appropriate antenna shuffling pattern, have been compared with a few other related schemes in terms of bit error rate (BER) and system capacity. The ‘Optimal’ antenna shuffling scheme improves the BER performance significantly with a gain of 2 dB at BER of 10-3 compared to all other schemes, while the ‘Max STBC’ antenna shuffling scheme enhances the V-BLAST/STBC system capacity by 4 %.

In this paper the BER performances are analyzed of a STBC encoded secured multiuser MIMO-OFDM wireless communication System. The 2X2 multi-antenna supported MIMO-OFDM system implements RSA cryptographic algorithm and ZF and MMSE based linear pre channel equalization schemes with deployment of various digital modulations (16-QAM, 16-PSK and 16-DPSK) over AWGN and Rayleigh fading channel. In this work the channel state information (CSI) is exploited at the transmitter side. It has been observed that the system under investigation outperforms with 16-QAM digital modulation and pre-MMSE channel equalization scheme and shows worst performance with 16-DPSK and pre-ZF. It is also observable that under situation of without implementing the pre channel equalization technique, the system provides satisfactory performance with 16-QAM and MMSE.

공간다중화 방식을 사용하는 MIMO 시스템은 다이버시티 기법을 사용하는 MIMO 시스템과 비교할 때 높은 전송률을 달성하지만 다이버시티 이득이 낮아 데이터 전송 신뢰도를 높이기 위하여 MIMO 수신단에서 공간정보스트림을 분리해야한다. 본 논문에서는 격자부호에 의한 채널 용량 검출 기법, 사용자 3인인 간섭채널과 선형검출기법인 ZF(Zero Forcing)와 MMSE(Minimum Mean Square Error) 검파 기법을 비교했다. 이때 채널은 Diagonal 채널이 된다. 즉, Diagonal 채널은 로 역행렬이 element-wise inverse로 Jacket 행렬의 성질을 만족함을 확인했다.

Compared to the MIMO system using the spatial multiplexing methods and the MIMO system using the diversity scheme achieved a high rate, but the lower the diversity gain to improve the data transmission reliability should separate the spatial stream at the MIMO receiver. In this paper, we compared Channel capacity detection methods with the Lattice code, the 3-user interference channel and linear channel interference detection methods ZF (Zero Forcing) and MMSE (Minimum Mean Square Error) detection methods. The channel is a Diagonal channel. In other words, Diagonal channel is confirmed by the inverse matrix satisfies the properties of Jacket are element-wise inverse to .

In this paper, we discuss joint detection schemes for an uplink cellular system when Base Station (BS) cooperation is possible for multi-cell users in a multi-cell scenario. Further, we analyze and evaluate the ML, ZF and ZF based SIC detection schemes. Although ML attains optimal performance, its complexity increases exponentially. Further, although ZF is simple, but exhibits the poor performance and SIC may give rise to error propagation. We propose a novel detection scheme, which combines the ZF detection and partial ML decoding scheme in order to improve the detection performance as well as to decrease the decoder complexity. Simulation results show that the proposed scheme attains nearly 2 dB reduction in the required SNR values to achieve the same BER performance. Further, the proposed scheme can be applied to MIMO detection for a single user and extended to other types of multi-user and multi-antenna based future smart BS cooperation.

Lattice-reduction (LR) techniques have been developed for signal detection in spatial multiplexing multiple input multiple output (MIMO) systems to obtain the largest diversity gain. Thus, an LR-assisted zero-forcing (ZF) receiver can achieve the maximum diversity gain in spatial multiplexing MIMO systems. In this paper, a simplified analysis of the achievable diversity gain is presented by fitting the channel coefficients lattice-reduced by a complex Lenstra-Lenstra-Lováz (LLL) algorithm into approximated Gaussian random variables. It will be shown that the maximum diversity gain corresponding to two times the number of receive antennas can be achieved by the LR-based ZF detector. In addition, the approximated bit error rate (BER) expression is also derived. Finally, the analytical BER performance is comparatively studied with the simulated results.

This research study has been made on the quality assessment of the multiview video signal transmitted in a correlated MIMO fading channel. In matlab based simulated system, pre- zero forcing channel Equalization/ precoding, two-dimensional nonlinear Median filtering for impulsive noise reduction schemes have been implemented under scenario of adding no additional redundant data for desired video signal protection. It is noteacable from such study that themultiview video signal with quite reasonably acceptable image quality is retrieved.

본 논문에서는 무선 통신에서의 높은 전송률과 신뢰도 있는 무선 통신 방안 중 터보 부호를 이용한 MIMO(Multiple Input Multiple Output) 통신 기법과 FTN(Faster Than Nyquist) 기법을 접목시켜 전송률을 향상시키며 신뢰성을 높일 수 있는 복호 방법을 제안한다. 기존의 계층적 시공간 부호화 기반의 MIMO-FTN(Multiple Input Multiple Output-Faster Than Nyquist) 기법은 FTN으로 인한 인접 심볼 간섭을 제거하기 위한 시공간 부호화 방식의 적용으로 전송률의 손해를 초래한다. 이러한 문제점을 해결하기 위해 본 논문에서는 ZF(Zero Forcing) 기법을 이용한 MIMO-FTN 기법에서 ZF 기법의 단점을 보완한 W-ZF(Weighted-Zero Forcing)을 이용한 방식을 제안한다. 본 논문에서는, 시뮬레이션을 통해 계층적 시공간 부호화 기반의 MIMO-FTN 기법과, W-ZF을 적용한 MIMO-FTN 기법, SISO-FTN 기법에서 FTN의 간섭량에 따른 성능과 전송률을 비교 하였다. 그 결과 W-ZF 기법을 적용한 MIMO-FTN 기법이 다른 두 기법보다 전송률에서 2배 더 좋은 것을 확인할 수 있다.

In this paper, we propose a decoding method that improves the transmission rate and reliability by integrating MIMO(Multiple Input Multiple Output) communication scheme using turbo code and FTN(Faster Than Nyquist) scheme among high rate and high reliability wireless communication schemes in wireless communication. The existing MIMO-FTN(Multiple Input Multiple Output-Faster Than Nyquist) scheme based on hierarchical space-time coded method induced data rate loss due to the application of the space-time trellis coding scheme to remove adjacent symbol interference due to FTN scheme. To solve these problems, this paper proposes a method using W-ZF(Weighted-Zero Forcing) which overcomes the disadvantages of ZF(Zero Forcing) scheme in MIMO-FTN scheme using ZF scheme. In this paper, we compared the performance and the transmission rate of the MIMO-FTN scheme based on the hierarchical space-time coding, the MIMO-FTN scheme using W-ZF and the SISO-FTN scheme. As a result, the MIMO-FTN scheme using the W-ZF scheme is two times better than the other two schemes.

본 논문은 광선추적법의 교차판별을 가속화할 수 있는 ZF-버퍼 방법을 제안한다. ZF-버퍼 방법은 광선추적법의 전처리 단계에서 Z-버퍼 방법을 적용하는데, 화면을 렌더링 하는 대신 화면에 렌더링 될 다각형 자료구조의 포인터를 기록하여 교차판별에 이용하는 방법이다. 결과적으로 해당 화소에서 광선과 교차할 가장 가까운 다각형을 찾아낼 수 있게 된다. ZF-버퍼 방법과 vista-버퍼 방법은 유사하지만 ZF-버퍼방법이 바운딩 볼륨을 사용하지 않고 화면에 나타날 다각형의 자료구조를 결과로 산출한다는 점이 다르다. 본 논문은 실험결과로서 9216개의 다각형으로 구성된 유타 주전자 영상을 사용하였으며 vista-버퍼와 비교하여 평균 3배정도의 속도 개선 효과가 있음을 확인하였으며, 또한 반사/굴절체에도 이 방법의 적용 가능성을 모색하였다.

In this work, we propose ZF-buffer algorithm in order to accelerate the intersection test of ray-tracing algorithm. ZF-buffer is used in the preprocessing of ray-tracing and records the pointer that points to a parent face of a depth value(z value) of an object determined in Z-buffer. As a result, the face which intersects with the first ray can be determined easily by using the pointer stored in F-buffer. Though ZF-buffer and vista-buffer resemble each other, the difference between the two methods is that what ZF-buffer records is not bounding volume but the pointer of a displayable face. We applied the ZF-buffer algorithm for the first ray to Utah teapot which consists of 9216 polygons. By comparing the elapse time of our method with vista-buffer algorithm, we can acquire improvement in speed that it is 3 times faster than vista-buffer algorithm. We expanded our algorithm to the second ray.

In this paper, we study an optimized block-diagonal zero-forcing (BD-ZF) precoder in a two-tiered cognitive network consisting of a macro cell (MC) and a small cell (SC). By exploiting multiuser multiple-input and multiple-output Vandermonde-subspace frequency-division multiplexing (VFDM) transmission, a cognitive SC can coexist with an MC. We first devise a cross-tier precoder based on the idea of VFDM to cancel the interference from the SC to the MC. Then, we propose an optimized BD-ZF intra-tier precoder (ITP) to suppress multiuser interference and maximize the throughput in the SC. In the case where the dimension of a provided null space is larger than that required by the BD-ZF ITP, the optimized BD-ZF ITP can collect all limited channel gain by optimizing rotating and selecting matrices. Otherwise, the optimized BD-ZF ITP is validated to be equivalent to the conventional BD-ZF ITP in terms of throughput. Numerical results are presented to demonstrate the throughput improvement of the proposed optimized BD-ZF ITP and to discover the impact of imperfect channel state information.

In this paper, we investigate the achievable sum rate and energy efficiency of downlink massive multiple-input multiple-output antenna systems with zero-forcing precoding, by taking into account the randomness of user locations. Specifically, we propose two types of non-uniform user distributions, namely, center-intensive user distribution and edge-intensive user distribution. Based on these user distributions, we derive novel tight lower and upper bounds on the average sum rate. In addition, the impact of user distributions on the optimal number of users maximizing the sum rate is characterized. Moreover, by adopting a realistic power consumption model which accounts for the transmit power, circuit power and signal processing power, the energy efficiency of the system is studied. In particular, closed-form solutions for the key system parameters, such as the number of antennas and the optimal transmit signal-to-noise ratio maximizing the energy efficiency, are obtained. The findings of the paper suggest that user distribution has a significant impact on the system performance: for instance, the highest average sum rate is achieved with the center-intensive user distribution, while the lowest average sum rate is obtained with the edge-intensive user distribution. Also, more users can be served with the center-intensive user distribution.

A method for sex determination of pigs was examined using polymerase chain reaction(PCR). Sex determining region Y(SRY) gene encoded on Y chromosome plays a key role for primary male development. Zinc finger X-Y(ZFX-ZFY) gene, one of the X-V homology gene group was found on the X and Y chromosomes, respectively, We tested for molecular sexing by amplification patterns of SRY and ZF genes. Genomic DNAs from various resources including porcine hairs and semen collected from domestic pig breeds and native pigs was used for PCR assay of each gene. The amplified products for porcine SRY gene were yielded only in males but not in females. On the other hand, two differential patterns were observed in amplification of ZF gene reflecting the chromosomal dimorphism by a length polymorphism between X and Y chromosomes. Of both, a common band was detected in all individuals tested so that this band might be amplified from ZFX gene as a PCR template, but another is specific for males indicated that from ZFY. The result of PCR assay provides identical information to that from investigation of phenotypic genders of the pigs tested. We suggest that this PCR strategy to determine porcine sexes using comparison of the amplification patterns of the SRY gene specific for Y chromosome and the dimorphic ZF gene between X and Y chromosomes may be a rapid and precise method for discrimination of two sexes and applied to DNA analysis of small samples such as embryonic blastomere, semen, and hairs.

Genistein, a inhibitor of the progression of G$_{1}$ and G$_{2}$ phase of the mammalian cell cycle, was discovered through a unique screening system, in which effects of microbial metabolites on the cycle progression of the cultured mouse mammalian carcinoma cell were monitored by flow cytometry. The inhibitor was extracted from the fermentation broth of Streptomyces sp. ZF10 with ethyl acetate, and purified by silica gel column chromatography and HPLC.

OFDM(orthogonal frequency division multiplexing) 시스템에서 무선 채널의 시변 특성으로 인해 인접캐리어 간의 간섭(ICI: intercarrier interference)이 발생하며 이로 인해 시스템 성능이 저하되게 된다. 이러한 현상은 도플러(doppler) 주파수가 커질수록 보다 크게 나타나게 된다. ICI의 영향을 완화하기 위하여 일반적인 ZF(zero-forcing) 선형 등화기를 사용할 수 있으나, 이 방식은 큰 행렬의 역행렬 계산이 요구되어 높은 복잡도를 가지게 된다. 본 논문에서는 OFDM 시스템에서 발생되는 ICI의 영향을 제거하기 위하여 적은 계산량을 가지는 ZF 등화 방식을 제안하고자 한다. 제안된 ZF 등화 방식은 역행렬 연산을 위한 수치적인 방법인 2차의 Neumann 급수와 특정한 부반송파에서 발생되는 ICI는 주로 인접 부반송파로부터 온다는 ICI의 특징을 이용한다. 또한, 적은 연산량으로 성능을 향상시키기 위하여 부분 ICI 제거 방법이 사용된다 복잡도 비교와 시뮬레이션 결과를 통해 제안된 ZF 등화 방식이 계산량을 크게 줄이면서도 일반적인 ZF 등화기법과 거의 동일한 성능을 보임을 확인한다.

In orthogonal frequency division multiplexing (OFDM) system the time selectivity of wireless channel introduces intercarrier interference (ICI), which degrades system performance in proportion to Doppler frequency. To mitigate the ICI effect, we can generally employ a classical zero-forcing (ZF) equalizer. However, the ZF scheme requires an inverse of a large matrix, which results in prohibitively high computational complexity. In this paper, we propose a low complexity ZF equalization scheme for suppressing the ICI caused by highly time-varying channels in OFDM systems. From the fact that the ICI on a subcarrier is mainly caused by several neighboring subcarriers, the proposed scheme exploits a numerical approximation for matrix inversion based on Neumann's Series (truncated second order). To further improve performance, the partial ICI cancellation technique is also used with reduced complexity. Complexity analysis and simulation results show that the proposed scheme provides the advantage of reducing computational complexity significantly, while achieving almost the same performance as that of the classical ZF a roach.

Trichoderma harzianum ZF-2 producing laccase was isolated from decaying samples from Shandong, China, and showed dye decolorization activities. The objective of this study was to optimize its culture conditions using a statistical analysis of its laccase production. The interactions between different fermentation parameters for laccase production were characterized using a Plackett-Burman design and the response surface methodology. The different media components were initially optimized using the conventional one-factor-at-a-time method and an orthogonal test design, and a Plackett-Burman experiment was then performed to evaluate the effects on laccase production. Wheat straw powder, soybean meal, and $CuSO_4$ were all found to have a significant influence on laccase production, and the optimal concentrations of these three factors were then sequentially investigated using the response surface methodology with a central composite design. The resulting optimal medium components for laccase production were determined as follows: wheat straw powder 7.63 g/l, soybean meal 23.07 g/l, $(NH_4)_2SO_4$ 1 g/l, $CuSO_4$ 0.51 g/l, Tween-20 1 g/l, $MgSO_4$ 1 g/l, and $KH_2PO_4$ 0.6 g/l. Using this optimized fermentation method, the yield of laccase was increased 59.68 times to 67.258 U/ml compared with the laccase production with an unoptimized medium. This is the first report on the statistical optimization of laccase production by Trichoderma harzianum ZF-2.