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91.
Kim H. Nam B.-G. Sohn J.-H. Woo J.-H. Yoo H.-J. 《Solid-State Circuits, IEEE Journal of》2006,41(11):2373-2381
A 32-bit fixed-point logarithmic arithmetic unit is proposed for the possible application to mobile three-dimensional (3-D) graphics system. The proposed logarithmic arithmetic unit performs division, reciprocal, square-root, reciprocal-square-root and square operations in two clock cycles and powering operation in four clock cycles. It can program its number range for accurate computation flexibility of 3-D graphics pipeline and eight -region piecewise linear approximation model for logarithmic and antilogarithmic conversion to reduce the operation error under 0.2%. Its test chip is implemented by 1-poly 6-metal 0.18-mum CMOS technology with 9-k gates. It operates at the maximum frequency of 231 MHz and consumes 2.18 mW at 1.8-V supply 相似文献
92.
93.
Kai Tang Ming-En Wang Lin-Lin Chen Shuo-Yan Chou Tony C. Woo Ravi Janardane 《Computer aided design》1997,29(12):825-836
A translational sweep is the translating of a polygon, called the generatrix G, around another polygon, called the directrix D, under two conditions: (1) G is always in contact with D; and (2) the interiors of G and D do not intersect. Three classes of translational sweep are studied, including the case in which both G and D are convex; the case in which G is convex, D monotone; and the case in which both are monotone. Efficient algorithms for computing the trajectory and the swept area as well as geometric and computational properties are presented for each class. A notion called the inverse generatrix, which reveals a duality between the trajectory and the swept polygon, is introduced to reduce complexity. 相似文献
94.
Electronic Business using eXtensible Markup Language (ebXML) Business Process Specification Schema (BPSS) supports the specification of the set of elements required to configure a runtime system in order to execute a set of ebXML business transactions. The BPSS is available in two stand-alone representations; a UML version and an XML version. Due to the limitations of UML notations and XML syntax, however, the current ebXML BPSS specification is insufficient to formally specify semantic constraints of modeling elements. In this study, we propose a classification scheme for BPSS semantic constraints, and describe how to represent those semantic constraints formally using Object Constraint Language. As a way to verify a particular Business Process Specification (BPS) with formal semantic constraint modeling, we suggest a rule-based approach to represent the formal semantic constraints, and describe a detail mechanism to apply the rule-based specified constraints to the BPS in a prototype implementation. 相似文献
95.
Chul Kim Chul Woo Park 《The International Journal of Advanced Manufacturing Technology》2006,29(5-6):459-474
This paper deals with an automated computer-aided process planning and die design system by which the designer can determine
operation sequences even if they have little experience in process planning and die design for axisymmetric products. An attempt
is made to link programs incorporating a number of expert design rules with the process variables obtained by commercial FEM
softwares, DEFORM and ANSYS, to form a useful package. The system is composed of four main modules. The process planning and
the die design modules consider several factors, such as the complexities of preform geometry, punch and die profiles, specifications
of available multi-former, and the availability of standard parts. They can provide a flexible process based on either the
reduction in the number of forming sequences by combining the possible two processes in sequence, or the reduction of deviation
of the distribution on the level of the required forming loads by controlling the forming ratios. In the die design module
optimal design technique and the horizontal split of the die insert were investigated for determining appropriate dimensions
of components of the multi-former die set. It is suggested that the proposed method can be beneficial for improving the tool
life of the die set in practice. 相似文献
96.
In a previous paper [J. Nucl. Mater. 137 (1985) 7], the present authors have shown that void-lattice formation in crystals under irradiation is a non-equilibrium disorder-order phase transition that is intimately related to the existence of a one-dimensionally diffusing, metastable excited self-interstitial state (crowdion), as assumed in the two-interstitial model. In contrast to all other models of void-lattice formation, this theory explains in a natural way why void lattices possess the same structure and orientation as the host crystal lattices.
In the present work, the theory is extended to the evolution of void lattices after their formation. The three most characteristic features of void-lattice evolution, viz., the occurrence of void-growth saturation, the size uniformity of voids in a void lattice, and the displacive stability of void lattices within a wide range of the governing parameters, are not only predicted by the present theory but can be traced to a common cause — the existence of one-dimensionally migrating crowdions, previously shown to be the cause of void-lattice formation. 相似文献
97.
Su-Jeong Bak Mingyu Son Jeehoon Shin Sun-I Kim Jung Woo Lee Duck Hyun Lee 《International journal of molecular sciences》2022,23(21)
We demonstrated highly active and durable hybrid catalysts (HCs) composed of small reduced graphene oxide (srGO) and carbon nanotubes (CNTs) for use as oxygen reduction reaction (ORR) catalysts in proton exchange membrane fuel cells. Pt/srGO and Pt/CNTs were prepared by loading Pt nanoparticles onto srGO and CNTs using a polyol process, and HCs with different Pt/CNT and Pt/srGO ratios were prepared by mechanically mixing the two components. The prepared HCs consisted of Pt/CNTs well dispersed on Pt/srGO, with catalyst HC55, which was prepared using Pt/srGO and Pt/CNTs in a 5:5 ratio, exhibiting excellent oxygen reduction performance and high stability over 1000 cycles of the accelerated durability test (ADT). In particular, after 1000 cycles of the ADT, the normalized electrochemically active surface area of Pt/HC55 decreased by 11.9%, while those of Pt/srGO and Pt/C decreased by 21.2% and 57.6%, respectively. CNTs have strong corrosion resistance because there are fewer defect sites on the surface, and the addition of CNTs in rGO further improved the durability and the electrical conductivity of the catalyst. A detailed analysis of the structural and electrochemical properties of the synthesized catalysts suggested that the synergetic effects of the high specific surface area of srGO and the excellent electrical conductivity of CNTs were responsible for the enhanced efficiency and durability of the catalysts. 相似文献
98.
Woo Kyung Ryu Sekyung Oh Jun Hyeok Lim Seung Jae Lee Hyun-Tae Shin Jeong-Seon Ryu 《International journal of molecular sciences》2022,23(17)
Circulating tumor DNA (ctDNA) has been utilized to monitor the clinical course of patients of non-small-cell lung cancer (NSCLC) who receive therapies targeting druggable mutations. However, despite providing valuable information on how NSCLC would naturally progress, the clinical utility of ctDNA for clinical-course monitoring and prediction of treatment-naïve NSCLC patients without druggable mutations remain unknown. We longitudinally followed a total of 12 treatment-naïve NSCLC patients, who did not harbor EGFR and ALK mutations, by collecting clinical information, radiological data, and plasma samples. Changes in ctDNA levels and tumor burden (TB) were compared with each other. New metastasis development, volume doubling time (VDT), and overall survival (OS) were analyzed regarding ctDNA detection at diagnosis. ctDNA was detected in the plasma of seven (58.3%) patients. Changes in ctDNA levels correlated with those in TB in a substantial fraction (57.1%) of patients and was also associated with brain metastasis, tumor necrosis, or pneumonia in other patients. All patients with ctDNA detection developed new metastasis during follow-ups in the organs that had been devoid of metastasis at diagnosis. The patients without ctDNA detection did not develop new metastasis (median duration of follow-ups: 9.8 months). In addition, patients with ctDNA detection had shorter VDT (p = 0.039) and worse OS (p = 0.019) than those without ctDNA detection. The natural course of NSCLC progression can be monitored by measuring ctDNA levels. Detection of ctDNA at diagnosis can predict development of new metastasis, rapid tumor growth and poor survival of NSCLC patients. 相似文献
99.
Sim-Kyu Bong No-June Park Sang Heon Lee Jin Woo Lee Aaron Taehwan Kim Xiaoyong Liu Sang Moo Kim Min Hye Yang Yong Kee Kim Su-Nam Kim 《International journal of molecular sciences》2022,23(17)
The activation and degranulation of immune cells play a pivotal role in allergic inflammation, a pathological condition that includes anaphylaxis, pruritus, and allergic march-related diseases. In this study, trifuhalol A, a phlorotannin isolated from Agarum cribrosum, inhibited the degranulation of immune cells and the biosynthesis of IL-33 and IgE in differentiated B cells and keratinocytes, respectively. Additionally, trifuhalol A suppressed the IL-33 and IgE-mediated activation of RBL-2H3 cells through the regulation of the TAK1 and MK2 pathways. Hence, the effect of trifuhalol A on allergic inflammation was evaluated using a Compound 48/80-induced systemic anaphylaxis mouse model and a house dust mite (HDM)-induced atopic dermatitis (AD) mouse model. Trifuhalol A alleviated anaphylactic death and pruritus, which appeared as an early-phase reaction to allergic inflammation in the Compound 48/80-induced systemic anaphylaxis model. In addition, trifuhalol A improved symptoms such as itching, edema, erythema, and hyperkeratinization in HDM-induced AD mice as a late-phase reaction. Moreover, the expression of IL-33 and thymic stromal lymphopoietin, inflammatory cytokines secreted from activated keratinocytes, was significantly reduced by trifuhalol A administration, resulting in the reduced infiltration of immune cells into the skin and a reduction in the blood levels of IgE and IL-4. In summarizing the above results, these results confirm that trifuhalol A is a potential therapeutic candidate for the regulation of allergic inflammation. 相似文献
100.
Chang-Gun Lee Soo-Jin Lee Seokho Park Sung-E Choi Min-Woo Song Hyo Won Lee Hae Jin Kim Yup Kang Kwan Woo Lee Hwan Myung Kim Jong-Young Kwak In-Jeong Lee Ja Young Jeon 《International journal of molecular sciences》2022,23(17)
The accumulation of hepatic lipid droplets (LDs) is a hallmark of non-alcoholic fatty liver disease (NAFLD). Appropriate degradation of hepatic LDs and oxidation of complete free fatty acids (FFAs) are important for preventing the development of NAFLD. Histone deacetylase (HDAC) is involved in the impaired lipid metabolism seen in high-fat diet (HFD)-induced obese mice. Here, we evaluated the effect of MS-275, an inhibitor of HDAC1/3, on the degradation of hepatic LDs and FFA oxidation in HFD-induced NAFLD mice. To assess the dynamic degradation of hepatic LDs and FFA oxidation in fatty livers of MS-275-treated HFD C57BL/6J mice, an intravital two-photon imaging system was used and biochemical analysis was performed. The MS-275 improved hepatic metabolic alterations in HFD-induced fatty liver by increasing the dynamic degradation of hepatic LDs and the interaction between LDs and lysozyme in the fatty liver. Numerous peri-droplet mitochondria, lipolysis, and lipophagy were observed in the MS-275-treated mouse fatty liver. Biochemical analysis revealed that the lipolysis and autophagy pathways were activated in MS-275 treated mouse liver. In addition, MS-275 reduced the de novo lipogenesis, but increased the mitochondrial oxidation and the expression levels of oxidation-related genes, such as PPARa, MCAD, CPT1b, and FGF21. Taken together, these results suggest that MS-275 stimulates the degradation of hepatic LDs and mitochondrial free fatty acid oxidation, thus protecting against HFD-induced NAFLD. 相似文献