• Proceedings of the Korean Society of Medical Physics Conference
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• 1999.11a
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• pp.147-148
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• 1999

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.274-274
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• 2004

조향성능은 완성된 자동차를 평가하는 아주 중요한 요소이며, 운전자에게 직접적인 영향을 가지는 까닭으로 우선적으로 해결되어야 할 문제이다. 자동차의 조향성능과 관련된 자동차 요소로는 프런트 샤시 모듈이 있으며, 프런트 샤시 모듈의 자세는 구성 요소인 서브프레임의 조립자세에 의하여 결정된다. 서브프레임은 4개의 원통형 지지부로 이루어져 있으며, 차체와의 조립시 지지부에 물리적 접촉이 발생한다. 즉 공간상에서 서브프레임의 자세는 지지부의 조립위치에 의하여 결정이 되며, 서브프레임의 자세를 결정하기 위해서는 지지부에 대한 적절한 해석이 필요하다.(중략)

• Journal of electromagnetic engineering and science
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• v.12 no.3
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• pp.223-225
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• 2012

In this paper, we develop a symbol/frame time and carrier frequency synchronization scheme for multi-carrier signaling in wireless mobile channels. The proposed scheme achieves simultaneous time synchronization and carrier frequency offset estimation. Simulation results show that the frequency offset of multiple sub-carrier spacings can be estimated and that performance is improved with robustness regardless of the cyclic prefix length.

• Journal of the Korean Institute of Landscape Architecture
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• v.21 no.3
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• pp.21-33
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• 1993

The evaluation is one of aspects of criticism, and thus it plays many roles in terms of the functions of criticism. The purpose of this study is to examine the evaluating criteria of landscape architectural works. The conclusions of this study are summarized as follows: The essential criterion of the evaluation is 'the originality' with respect to history(or tradition) of landscape architecture. And the sub-criteria of the evaluation can be invented through a frame;[↔ ↔].

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.05a
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• pp.135-135
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• 2012

세계 환경유해물질 규제에 대응하여 반도체 substrate의 Pb-free solution의 일환으로 등장한 PPF (Pre-Plated Frame)는 패키지공정 조립성은 물론, 자동차 반도체와 같은 고 신뢰성 및 low cost 요구를 만족하기 위해 초박막 고품질의 도금층과 Sub-micro scale의 rough treatment 와 같은 미세 표면제어 기술, 그리고 Au wire로부터 Cu wire 로의 전환에 대응하는 최적화된 도금층 구조로 발전하고 있다. 이러한 기술적인 진화를 거듭해온 이 기술은 다양한 반도체 substrate에 광범위하게 사용될 수 있기 때문에 향후 PPF기술의 활용저변은 더욱 확대될 전망이다.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.281-284
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• 2002

Error resilience for image coding is an important component of multimedia communication system. Error resilience schemes address loss recovery from the compression perspective. Multiple description coding (MDC) is one of the error resilience techniques promising for robust video transmission. It is the way to achieve tradeoff description such as scalar quantization, correlating transform and the quantized frame expansion. In this paper, we consider Multiple Description Scalar Quantization (MDSQ) to wavelet domain. Conventional MDSQ schemes considered description with equal weights in each sub-bands. But, we can see that the each sub-bands is unequal contribution to whole image quality. Therefore, we experiment the multiple design MDSQ table to make probability of zero index high, which gives high efficiency in arithmetic symbol coder. We also compare our proposed method with the conventional methods and show improved performance in terms of redundancy-rate-distortion.

• Journal of Korea Multimedia Society
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• v.12 no.6
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• pp.785-793
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• 2009

This paper proposes a signature using dominant singular values for video sequence matching. By considering the input image as matrix A, a partition procedure is first performed to separate the matrix into non-overlapping sub-images of a fixed size. The SVD(Singular Value Decomposition) process decomposes matrix A into a singular value-singular vector factorization. As a result, singular values are obtained for each sub-image, then k dominant singular values which are sufficient to discriminate between different images and are robust to image size variation, are chosen and normalized as the signature for each block in an image frame for matching between the reference video clip and the query one. Experimental results show that the proposed video signature has a better performance than ordinal signature in ROC curve.

• Journal of the Korean Mathematical Society
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• v.48 no.1
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• pp.159-167
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• 2011

We consider a curve $\alpha$= $\alpha$(s) in Minkowski 3-space $E_1^3$ and denote by {T, N, B} the Frenet frame of $\alpha$. We say that $\alpha$ is a slant helix if there exists a fixed direction U of $E_1^3$ such that the function is constant. In this work we give characterizations of slant helices in terms of the curvature and torsion of $\alpha$. Finally, we discuss the tangent and binormal indicatrices of slant curves, proving that they are helices in $E_1^3$.

• Journal of Korea Society of Industrial Information Systems
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• v.17 no.2
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• pp.29-32
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• 2012

Computer generated holography (CGH) is technology for generating holograms of synthetic, three dimensional (3D) objects which may not exist in the physical world. The process, however, requires heavy amount of computation as the resolution of a hologram is significantly higher than that of a typical optical image. This paper reviews four modern techniques for fast generation of digital Fresnel holograms which are important in the development of holographic video systems. The methods that will be described include the virtual window, sub-line, wavefront recording plane (WRP), and the interpolative WRP schemes. These works share the common objective to generate digital Fresnel hologram at a speed that is close to the video frame rate, and with complexity which is realizable with affordable computing and reconfigurable hardware devices. The author will present the principles and realization of these works, as well as some potential area of research in digital holography.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.273-277
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• 2009

A compressed video stream is very sensitive to transmission errors that may severely degrade the reconstructed image. Therefore, error resilience is an essential problem in video communications. In this paper, we propose novel temporal error concealment techniques for recovering lost or erroneously received macroblock (MB). To reduce the computational complexity, the proposed method adaptively determines the search range for each lost MB to find best matched block in the previous frame. And the original corrupted MB split into for $8{\times}8$ sub-MBs, and estimates motion vector (MV) of each sub-MB using its boundary information. Then the estimated MVs are utilized to reconstruct the damaged MB. In simulation results, the proposed method shows better performance than conventional methods in both aspects of PSNR.