• Design & Manufacturing
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• v.7 no.1
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• pp.19-22
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• 2013

Almost all injection molds have multi-cavity runner system for mass production, which are designed with geometrically balanced runner system in order to accomplish filling balance between cavity to cavity during processing. However, even though geometrically balanced runner is used, filling imbalances have been observed. So, many studies for improving filling balance in the multi-cavities molds are worked up. In this study, the Melt-Buffer which is a new runner system for filling balance has been suggested, and a series of experiment about degree of filling balance in cavity-to-cavity was conducted in the mold with the Melt-Buffer. From the experiment, the filling balance was increased up to 5~6% by using the Melt-Buffer.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.584-586
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• 2007

3D virtual modeling such as creation of a cyber city or landscape, or making a 3D GIS requires realistic textures. Automatic texture extraction using close range images is not yet efficient or easy in terms of data acquisition and processing. In this paper, common problems associated with automatic texture extraction from aerial photographs are explored. The ZI-buffer, which has depth and facet ID fields, is proposed to remove hidden pixels. The ZI-buffer algorithm reduces memory burden and identifies visible facets. The correct spatial resolution for facet gridding is tested. Error pixels in the visibility map were removed by filtering.

• 한국금형공학회:학술대회논문집
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• 2008.06a
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• pp.95-98
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• 2008

Almost all injection molds have multi-cavity runner system for mass production, which are designed with geometrically balanced runner system in order to accomplish filling balance between cavity to cavity during processing. However, even though geometrically balanced runner is used, filling imbalances have been observed. So, many studies for improving filling balance in the multi-cavities molds are worked up. In this study, the Melt-Buffer which is a new runner system for filling balance has been suggested, and a series of experiment about degree of filling balance in cavity-to-cavity was conducted in the mold with the Melt-Buffer. From the experiment, the filling balance was increased up to $5^{\sim}6%$ by using the Melt-Buffer.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.2
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• pp.228-235
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• 2004

In this thesis, it is designed efficient electrode formation on the organic luminescent device. ITO electrode is treated with $O_2$plasma. In order to inject hole efficiently, there is proposed the shape of anode that inserted plasma polymerized films as buffer layer between anode and organic layer using thiophene monomer. It is realized efficiently electron injection to aluminum due to introduce the quantum well in cathode. In the case of device inserted the buffer layer by using the plasma poiymerization after $O_2$plasma processing for ITO transparent electrode, since it forms the stable interface and reduce the moving speed of hole, the recombination of hole and electronic ate made in the omitting layer. Compared with the devices without buffer layer, the turn-on voltage was lowered by 1.0(V) doc to the introduction of buffer layer Since the quantum well structure is formed in front of cathode to optimize the tunneling effect, there is improved the power efficiency more than two times.

• The KIPS Transactions:PartA
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• v.8A no.4
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• pp.385-390
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• 2001

In this paper, we describe a blocking method of buffer overflow attack for secure operating system. Our team developed secure operating system using MAC and ACL access control added on Linux kernel. We describe secure operating system (SecuROS) and standardized Secure utility and library. A working prototype able to detect and block buffer overflow attack is available.

• Progress in Superconductivity and Cryogenics
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• v.8 no.4
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• pp.19-21
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• 2006

Biaxially textured Ni was fabricated by electrodeposition process and delaminated from the biaxially textured cathode surface for further buffer layer deposition process. Those electrode posited Ni substrates showed well-developed biaxial texture and smooth surface. In order to improve the thermal stability of Ni substrates, Mn was alloyed by adding Mn precursor into the electrodeposition bath. Subsequently, $CeO_2$ buffer layers are deposited by MOD process to prevent interfacial reaction between superconductor and substrates. In particular, Bismuth oxide was added to $CeO_2$ to realize lower temperature processing of buffer layers. The microstructure and texture development of each layers have been investigated. Preliminary results shows that all electro/chemical process can be a candidate for cost effective route to YBCO coated conductor.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.257.1-257.1
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• 2015

Cu(In,Ga)Se2 (CIGS) 박막 태양 전지에서 buffer layer는 CIGS 흡수층과 TCO 사이의 밴드갭 차이에 대한 문제점과 lattice mismatch를 해결하기 위해 필수적이다. 흔히 buffer layer 물질로는 CdS가 가장 많이 사용되고 있으나 Cd의 독성에 관한 문제가 야기되고 있다. 따라서 ZnS(O, OH) buffer layer가 친환경 물질로 기존의 CdS 버퍼 층의 대체 물질로 각광 받고 있으며, 단파장 범위에서 높은 투과율로 인해 wide band gap의 Chalcopyrite 태양 전지에 응용되는 buffer layer로 많은 연구가 이루어지고 있다. 또한 buffer layer를 최적화 하여 carrier lifetime과 양자 효율이 증가시킬 수 있는 특성을 가지고 있다. 이 연구에서는 Cu(In,Ga)Se2 (CIGS) 박막에 화학습식공정 (CBD) 방법을 이용하여 최적화된 ZnS(O, OH)의 증착 조건을 찾고, 고품질의 buffer layer를 제조하기 위한 실험에 초점을 맞췄다. 또한, buffer layer의 막질을 개선하고 균일한 막을 제조하기 위해 processing parameters인 시약의 농도, 제조 시간 및 온도 등의 다양한 변화를 통해 실험을 진행하였다. 그 후 최적화된 ZnS(O, OH) buffer layer의 특성 분석을 위해 X-ray diffraction(XRD), photoluminescence (PL), scanning electron microscope (SEM) and GD-OES을 이용하였고, 이를 통해 제조된 CIGS 박막 태양전지는 light induced current-voltage (LIV) and external quantum efficiency (EQE)를 통해 특성 분석을 실시 하였다. 결과적으로, 제조된 ZnS(O, OH) buffer layer의 $ZnSO4{\cdot}7H2O$의 농도는 0.16 M, Thiourea는 0.5 M, NH4OH는 7.5 M, 그리고 반응 온도는 77.5 oC의 조건 하에 CIGS 기판 위에 균일하고 균열이 없는 ZnS(O, OH) 박막을 제조하였으며 이때 제조된 태양전지의 소자 특성은 Voc = 0.478 V, Jsc = 35.79 mA/cm2, FF = 47.77%, ${\eta}=8,18 %$이다.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.49 no.8
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• pp.63-72
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• 2012

In this paper, we proposed a parallel architecture of line & block edge filter for high-performance H.264/AVC deblocking filter for Quad Full High Definition(Quad FHD) video real time processing. To improve throughput, we designed 4-parallel block edge filter with 16 line edge filter. To reduce internal buffer size and processing cycle, we scheduled 4-parallel zig-zag scan order as deblocking filtering order. To avoid data conflicts we placed 1 delay cycle between block edge filtering. We implemented interleaving buffer, as internal buffer of block edge filter, to sharing buffer for reducing buffer size. The proposed architecture was simulated in 0.18um standard cell library. The maximum operation frequency is 108MHz. The gate count is 140.16Kgates. The proposed H.264/AVC deblocking filter can support Quad FHD at 113.17 frames per second by running at 90MHz.

• The Transactions of the Korea Information Processing Society
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• v.3 no.7
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• pp.1669-1679
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• 1996

In this paper, we address the problem of how to replace huffers in multimedia database systems with time-varying skewed data access. The access pattern in the multimedia database system to support audio-on-demand and video-on-demand services is generally skewed with a few popular objects. In addition the access pattem of the skewed objects has a time-varying property. In such situations, our analysis indicates that conventional LRU(least Recently Used) and LFU(Least Frequently Used) schemes for buffer replacement algorithm(ABRN:Adaptive Buffer Replacement using Neural suited. We propose a new buffer replacement algorithm(ABRN:Adaptive Buffer Replacement using Neural Networks)using a neural network for multimedia database systems with time-varying skewed data access. The major role of our neural network classifies multimedia objects into two classes:a hot set frequently accessed with great popularity and a cold set randomly accessed with low populsrity. For the classification, the inter-arrival time values of sample objects are employed to train the neural network.Our algorithm partitions buffers into two regions to combine the best roperties of LRU and LFU.One region, which contains the 핫셋 objects, is managed by LFU replacement and the other region , which contains the cold set objects , is managed by LRUreplacement.We performed simulation experiments in an actual environment with time-varying skewed data accsee to compare our algorithm to LRU, LFU, and LRU-k which is a variation of LRU. Simulation resuults indicate that our proposed algorthm provides better performance as compared to the other algorithms. Good performance of the neural network-based replacement scheme means that this new approach can be also suited as an alternative to the existing page replacement and prefetching algorithms in virtual memory systems.

• Journal of KIISE:Databases
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• v.35 no.6
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• pp.469-480
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• 2008

A shared disk (SD) cluster couples multiple nodes for high performance transaction processing, and all the coupled nodes share a common database at the disk level. To reduce the number of disk accesses, each node caches database pages in its memory buffer. Since a particular page may be cached simultaneously in different nodes, cache consistency should be maintained to ensure that nodes can always access the most recent version of database pages. Most cache consistency schemes proposed in the SD cluster adopted LRU as a buffer replacement algorithm. In this paper, we first present four buffer replacement algorithms that consider the characteristics of the SD cluster. Then we compare the performance of the buffer replacement algorithms. We perform the experiments on a variety of cluster configurations and database workloads. The experiment results show that the proposed algorithms achieve performance improvement up to 5 times of LRU algorithm.