• JSTS:Journal of Semiconductor Technology and Science
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• v.10 no.3
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• pp.232-239
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• 2010

By using the clock timing control at transmitter (TX), the crosstalk-induced jitter (CIJ) is compensated for in the 2-bit parallel data transmission through the coupled microstrip lines on printed circuit board (PCB). Compared to the authors' prior work, the delay block circuit is simplified by combining a delay block with a minimal number of stages and a 3-to-1 multiplexer. The delay block generates three clock signals with different delays corresponding to the channel delay of three different signal modes. The 3-to-1 multiplexer selects one of the three clock signals for TX timing depending on the signal mode. The TX is implemented by using a $0.18\;{\mu}m$ CMOS process. The measurement shows that the TX reduces the RX jitters by about 38 ps at the data rates from 2.6 Gbps to 3.8 Gbps. Compared to the authors' prior work, the amount of RX Jitter reduction increases from 28 ps to 38 ps by using the improved implementation.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.3
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• pp.179-185
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• 2019

This paper proposes a block-type classification based image binarization for the implementation of the low-power feature extraction algorithm. The proposed method can be implemented with threshold value re-use technique approach when the image divided into $64{\times}64$ macro blocks size and calculating the threshold value for each block type only once. The algorithm is validated based on quantitative results that only a threshold value change rate of up to 9% occurs within the same image/block type. Existing algorithms should compute the threshold value for 64 blocks when the macro block is divided by $64{\times}64$ on the basis of $512{\times}512$ images, but all suggestions can be made only once for best cases where the same block type is printed, and for the remaining 63 blocks, the adaptive threshold calculation can be reduced by only performing a block type classification process. The threshold calculation operation is performed five times when all block types occur, and only the block type separation process can be performed for the remaining 59 blocks, so 93% adaptive threshold calculation operation can be reduced.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.12
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• pp.3329-3343
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• 1995

The interaction of mixed convection and surface radiation in a printed circuit board(PCB) is investigated numerically. The electronic equipment is modeled by a two-dimensional channel with three hot blocks. In order to calculate the turbulent flow characteristics, the low Reynolds number k-.epsilon. model which is proposed by Launder and Sharma is applied. The S-4 approximation is used to solve the radiative transfer equation. The effects of the Reynolds number and geometric configuration variation of PCB on the flow and heat transfer characteristics are analyzed. As the results of this study, it is found that the thermal boundary layer occured at adiabatic wall in case with thermal radiation included, and the effect of radiation is also found to be insignificant for high Reynolds numbers. It is found, as well, that the heat transfer increases as the Reynolds number and block space increase and the channel height decreases and the heat transfer of vertical channel is greater than that of horizontal channel.

• Journal of Korean Foot and Ankle Society
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• v.27 no.3
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• pp.112-116
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• 2023

A 74-year-old female patient, who underwent surgery for a left distal tibiofibular fracture 40 years earlier, visited the hospital with an ankle varus deformity due to malunion. The patient complained of discomfort while walking due to the ankle and hindfoot varus deformity but did not complain of ankle pain. Therefore, correction using supramalleolar osteotomy was planned, and through virtual surgical simulation, it was predicted that a correction angle of 24° and an osteotomy gap open of 12 mm would be necessary. An osteotomy guide and an osteotomy gap block were made using three-dimensional (3D) printing to perform the osteotomy and correct the deformity according to the predicted goal. One year after surgery, it was observed that the ankle varus was corrected according to the surgical simulation, and the patient was able to walk comfortably. Thus, for correction of deformity, virtual surgical simulation and a 3D-printed osteotomy guide can be used to predict the target value for correction. This is useful for increasing the accuracy of correction of the deformity.

• International conference on construction engineering and project management
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• 2020.12a
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• pp.75-84
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• 2020

Modular construction is a construction method whereby prefabricated volumetric units are produced in a factory and are installed on site to form a building block. The construction productivity can be substantially improved by the manufacturing and assembly of standardized modular units. 3D printing is a computer-controlled fabrication method first adopted in the manufacturing industry and was utilized for the automated construction of small-scale houses in recent years. Implementing 3D printing in the fabrication of modular units brings huge benefits to modular construction, including increased customization, lower material waste, and reduced labor work. Such implementation also benefits the large-scale and wider adoption of 3D printing in engineering practice. However, a critical issue for 3D printed modules is the loading capacity, particularly in response to horizontal forces like wind load, which requires a deeper understanding of the building structure behavior and the design of load-bearing modules. Therefore, this paper presents the state-of-the-art literature concerning recent achievement in 3D printing for buildings, followed by discussion on the opportunities and challenges for examining 3D printing in modular construction. Promising 3D printing techniques are critically reviewed and discussed with regard to their advantages and limitations in construction. The appropriate structural form needs to be determined at the design stage, taking into consideration the overall building structural behavior, site environmental conditions (e.g., wind), and load-carrying capacity of the 3D printed modules. Detailed finite element modelling of the entire modular buildings needs to be conducted to verify the structural performance, considering the code-stipulated lateral drift, strength criteria, and other design requirements. Moreover, integration of building information modelling (BIM) method is beneficial for generating the material and geometric details of the 3D printed modules, which can then be utilized for the fabrication.

• Journal of Korea Multimedia Society
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• v.4 no.3
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• pp.247-256
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• 2001

Digital watermarking is a copyright protection technique for digital images which embed a code into the digital data so the data is marked. Watermarking techniques previously deal with on-line digital data and have been developed to withstand digital attacks such image processing, compression and geometric transformation. In this paper we propose a novel method of embedding watermarks in printed images. In the proposed algorithm, watermark is embedded in a dithered binary image by comparing the $2\times{2}$ blocks of the counting array is the number of 1 (WHITE) in the $16\times{16}$ blocks of the dithered binary image with predefined reference block pattern, which is generated by watermark values. The proposed algorithm is able to provide more information at a watermark because the proposed algorithm use both '1'and '0' as watermark values. The watermark information is detected by comparing the watermark which is reconstructed from the image which is embedded watermark with the original watermark which is embedded in a binary image. The performance of the proposed algorithm is compared with that of the conventional watermark embedding algorithm for printed images by detecting watermark for scan images.

• Journal of the Korean Society for Library and Information Science
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• v.41 no.4
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• pp.331-346
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• 2007

The purpose of this study is to research into the characteristics of the printed hooks of ${\ulcorner}$Ch'un-ch'iu(春秋)${\lrcorner}$ commentary in Chosun dynasty by analyzing the types and forms of the existing printed books through the investigation of the bibliographic records of the books. To achieve this purpose, this study selected some of the 'Chak-pan' catalog(冊板目錄) printed in Chosun dynasty which has relatively clear and accurate history and investigated the block printing's condition of the printed books of ${\ulcorner}$Ch'un-ch'iu(春秋)${\lrcorner}$ commentary. In addition. a comprehensive book catalog of ${\ulcorner}$Ch'un-ch'iu(春秋)${\lrcorner}$ commentary was created by retrieving old book catalog from databases by several authoritative information centers and university libraries. Based on this catalog, this research created a new 'Union Catalog(綜合書目)' which contains bibliographies of the ${\ulcorner}$Ch'un-ch'iu(春秋)${\lrcorner}$ commentary through field investigations by identifying, picture-taking. and copying the real books. The new union catalog functions as the basis of the bibliographic analysis of this research.

• The Transactions of the Korea Information Processing Society
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• v.4 no.5
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• pp.1277-1288
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• 1997

In this paper,the extraciton method for individual and the recognition method for the printed dociments are discussed. In preprocessing is a technique to extract characters that are difficult to manage such as touching characters or overlapped chracters.Genrally in the existing segmentation methods,projection and edge detection are applied.However,in this paper an indvidual character is extracted by using connected pixel with one projection after the string extraction The maximum Blok Methld(MBM)is used for the recognition.The MBM is a method to enlarge the block to the last point the pixel that was found during projection. The maximum blocks are skeletonxied after the division into straight line block and oblique line block.Especially,in the recognition of chinese chracters compared to the existing method it showed improved recognition rate.

• Journal of electromagnetic engineering and science
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• v.14 no.1
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• pp.15-24
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• 2014

A compact dual-band three-way metamaterial power divider is proposed that has three in-phase outputs. Fully printed composite rightand left-handed (CRLH) unequal and equal power dividers are first implemented for 900-MHz and 2.4-GHz bands with the power-division ratios of 2:1 and 1:1, respectively. An initial 1:1:1 power divider is then achieved by incorporating the input of the two-way equal block into an output of the unequal block, and trimming the interconnection parameters. The condition of an identical phase at the three outputs of the power divider is then met by devising a hybrid CRLH phase-shift line to compensate for the different phase errors at the two frequencies. This scheme is confirmed by predicting the performance of the power divider with circuit analysis and full-wave simulation and measuring the fabricated prototype. They results show agreement; the in-phase outputs as well as the desirable power-division are accomplished and outdo the conventional techniques.

• Korean Journal of Heritage: History & Science
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• v.33
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• pp.366-396
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• 2000

This research paper has examined the question of the year of the publication of the wood block print, Mukujeonggwang Dae Darani Gyeong(Pure light Dharani Sutra). Published in Korea sometime before 751, it is known to be the oldest existing document printed with wood blocks in the world. Recently, a Chinese scholar claimed that this sutra was translated into Chinese in 701 and printed in Reoyang, China, in 702. These claims have lead to international symposiums and research papers on the Mukujeonggwang Dae Darani Gyeong. However, although diverse opinions and research were presented by various scholars, they all seem to be far fetched and do not answer the essential question of the sutra. The evidence in historic records shows that the translation into Chinese was done in 704 and not in 701. After it was translated into Chinese, it came to Korea and was printed with wood blocks. When Sokkatap was built in 751, a copy was placed in the pagoda. Moreover, the inscription on the sarira casket states that the construction of the pagoda was based on the theory of Jotapsasang contained in the sutra. Thus this proves that Mukujeonggwang Dae Darani Gyeong had to have been printed before 751.