객체 관계형 데이타베이스 관리 시스템을 이용한 디지털 앨범의 설계 및 구현

이준서,장염승,한기준 건국대학교 산업기술연구원 2000 건국기술연구논문지 Vol.25 No.-

As the storage capacity of a computer system is rapidly increasing and the cost of computer hardware is decreasing continuously, users can easily manage multimedia data on the personal computer. Especially, various image view programs are widely used to manage image files at the present time. However, since most of these programs do not use a database management system(DBMS), it is very difficult for users to use them efficiently. In this paper, we designed and implemented a Digital Album by using an object-relational database management system, called PARODY(Persistent, Almost, Relational Object Database sYstem) that implements a persistent object database with a relatively simple interface to its C++ class library. Since PARODY is used as a data storage manager of the Digital Album, users can manage(i.e., insert, update, and delete) an image database and search for the required image data from the image database easily. In addition, we use OWL(Object Windows Library) of Borland C++ to implement the user interface of the Digital Album efficiently.

Health-related Quality of Life After Treatment for Malignant Bone Tumors: A Follow-up Study in China

Sun, Yong-Jian,Hu, Yan-Jun,Jin, Dan,Li, Jian-Wei,Yu, Bin Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.7

Aim: We conducted the present study to assess health-related quality of life (HRQoL) among bone cancer patients after surgical treatment in one large teaching hospitals in China, and assess the risk factors for improving the physical or mental HRQoL. Methods: 344 eligible adult patients who were admitted to the hospital with malignant bone tumors during the period of Jun. 2008 to Dec. 2011, and a reference group with 361 health cases was recruited in the same hospital during the same period. All 344 patients were followed up for one year. The HRQoL before treatment and after one year was evaluated with the Medical Outcome Short Form 36 (SF-36). Results: All 8 domains of HRQoL had the lowest scores greatly improved over the first year after discharge. However, the patients still had significantly lower scores in every domain than the reference group one year after discharge. Age and type of surgery were associated with HRQoL in the mental domain. Conclusion: The HRQoL of patients with malignant bone tumors greatly improved one year after the treatment. This study also highlighted the utility of HRQoL assessment for prognostic evaluation of patients after surgical treatment for bone cancer.

Investigations into film cooling and unsteady flow characteristics in a blade trailing-edge cutback region

Yan Gao,Xin Yan,Jun Li,Kun He 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.10

Unsteady flow characteristic and film cooling effect in the blade trailing edge cutback region are numerically investigated using DES (detached eddy simulation) method at three blowing ratios, four lip thickness ratios and three rib geometries. With the experimental data, reliability and accuracy of the numerical methods are validated. The results indicate that, compared with RANS (Reynolds-averaged Navier-Stokes) equations solutions, the DES method has a superior accuracy in predicting the film cooling effectiveness on trailing-edge cutback. The lip thickness has a pronounced effect on shedding vortex scale downstream the slot. As the lip thickness ratio decreases, the film cooling effect on trailing edge cutback is improved. Compared with the line ribs, the arrangement of pin fin ribs enhances the uniformity of coolant coverage on trailing edge cutback along lateral direction. However, with different types of rib, the film cooling effectiveness on the trailing edge cutback is mainly determined by the stable cooling flow structures and mixing effect between mainstream and coolant. The development of vortex system downstream the slot is significantly affected by the blowing ratio, which in turn influences the film cooling effect on trailing edge cutback.

Computing and Reducing Transient Error Propagation in Registers

Jun Yan,Wei Zhang 한국정보과학회 2011 Journal of Computing Science and Engineering Vol.5 No.2

Recent research indicates that transient errors will increasingly become a critical concern in microprocessor design. As embedded processors are widely used in reliability-critical or noisy environments, it is necessary to develop cost-effective fault-tolerant techniques to protect processors against transient errors. The register file is one of the critical components that can significantly affect microprocessor system reliability, since registers are typically accessed very frequently, and transient errors in registers can be easily propagated to functional units or the memory system, leading to silent data error (SDC) or system crash. This paper focuses on investigating the impact of register file soft errors on system reliability and developing cost-effective techniques to improve the register file immunity to soft errors. This paper proposes the register vulnerability factor (RVF) concept to characterize the probability that register transient errors can escape the register file and thus potentially affect system reliability. We propose an approach to compute the RVF based on register access patterns. In this paper, we also propose two compiler-directed techniques and a hybrid approach to improve register file reliability cost-effectively by lowering the RVF value. Our experiments indicate that on average, RVF can be reduced to 9.1% and 9.5% by the hyperblock-based instruction re-scheduling and the reliability-oriented register assignment respectively, which can potentially lower the reliability cost significantly, without sacrificing the register value integrity.

An Interference Matrix Based Approach to Bounding Worst-Case Inter-Thread Cache Interferences and WCET for Multi-Core Processors

Jun Yan,Wei Zhang 한국정보과학회 2011 Journal of Computing Science and Engineering Vol.5 No.2

Different cores typically share the last-level cache in a multi-core processor. Threads running on different cores may interfere with each other. Therefore, the multi-core worst-case execution time (WCET) analyzer must be able to safely and accurately estimate the worst-case inter-thread cache interference. This is not supported by current WCET analysis techniques that manly focus on single thread analysis. This paper presents a novel approach to analyze the worst-case cache interference and bounding the WCET for threads running on multi-core processors with shared L2 instruction caches. We propose to use an interference matrix to model inter-thread interference, on which basis we can calculate the worst-case inter-thread cache interference. Our experiments indicate that the proposed approach can give a worst-case bound less than 1%, as in benchmark fib-call, and an average 16.4% overestimate for threads running on a dual-core processor with shared-L2 cache. Our approach dramatically improves the accuracy of WCET overestimatation by on average 20.0% compared to work.

Base Station Placement for Wireless Sensor Network Positioning System via Lexicographical Stratified Programming

( Jun Yan ),( Kegen Yu ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.11

This paper investigates optimization-based base station (BS) placement. An optimization model is defined and the BS placement problem is transformed to a lexicographical stratified programming (LSP) model for a given trajectory, according to different accuracy requirements. The feasible region for BS deployment is obtained from the positioning system requirement, which is also solved with signal coverage problem in BS placement. The LSP mathematical model is formulated with the average geometric dilution of precision (GDOP) as the criterion. To achieve an optimization solution, a tolerant factor based complete stratified series approach and grid searching method are utilized to obtain the possible optimal BS placement. Because of the LSP model utilization, the proposed algorithm has wider application scenarios with different accuracy requirements over different trajectory segments. Simulation results demonstrate that the proposed algorithm has better BS placement result than existing approaches for a given trajectory.

The Effect of H2O2/Fe2+ Catalytic Oxidation System on the Morphology, Structure and Properties of Flake-Like Poly(2,3-dimethylaniline)

Jun Yan,Li Ma,Mengyu Gan,Xiao Li,Zhitao Li,Jihai Tang,Ying Tu,Haifeng Hu 한국고분자학회 2014 Macromolecular Research Vol.22 No.8

In this work, flake-like poly(2,3-dimethylaniline) (P(2,3-DMA)) with enhanced thermal stability andanticorrosive ability was synthesized by in situ polymerization using H2O2/Fe2+ catalytic oxidation system, comparingwith traditional oxidant ammonium persulfate (APS) synthetic method. The structure and morphology of thesamples were characterized Fourier transform infrared (FTIR) spectra, X-ray diffraction (XRD) and field-emissionscanning electron microscope (FESEM). The experimental results demonstrated that using H2O2/Fe2+ catalytic oxidationsystem was more inclined to form the two-dimensional P(2,3-DMA) flakes. The enhancement in thermostabilityand corrosion resistance was attributed to the formation of phenazine-like structures in the polymer chains,which could serve as templates to form the flake-like morphology. In addition, using H2O2/Fe2+ catalytic oxidationsystem is more environmental friendly than the APS method that can avoid ammonium pollution on aquatic life aswell as waters.

Evaluation of Pp/Clay Composites as Soundproofing Material

Yan, Jun,Kim, Myung-Sub,Kang, Kyung-Min,Joo, Kyung-Hoon,Kang, Yeon-June,Ahn, Sung-Hoon RAPRA 2014 POLYMERS AND POLYMER COMPOSITES Vol.22 No.1

Noise should be disappeared or reduced by using soundproofing materials in our daily life. Polypropylene (PP)/Clay composites are interesting because of their physical and mechanical properties dramatically increased by small quantity of clay filled in PP matrix. In this paper, different types of specimens were made at 0.9, 2.9, 4.8, 6.5, 8.2 and 9.9 wt.% of organically modified clay reinforced PP (100 gram) by solvent based techniques. A heating press and laser cutting process were used to create specimens with thickness 3 mm, diameter 29 mm and 100 mm for high and low sound frequency test, respectively. The soundproofing property was measured by sound transmission loss (TL) through impedance tube method. The measured results showed that about 7 similar to 14.8 dB sound TL was increased for 29 mm diameter PP/Clay (6.5 wt.%) composite specimens compared with pure PP at 3200 similar to 6400Hz. And about 3.3 similar to 5.3 dB sound TL was increased for 100 mm diameter PP/Clay (6.5 wt.%) composite specimens compared with pure PP at 520 similar to 640Hz. In addition, mechanical properties of this composite were measured, and TEM images were taken in order to observe the micro-structure for research on relationship between soundproofing property and micromechanism.

Improved Longitudinal Displacement Profile and Initial Support for Tunnel Excavation

Yan-Jun Zhang,Kai Su,Zhong-Dong Qian,He-Gao Wu 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.6

The ground support system has a significant impact on tunnel safety while the installation time of initial support is commonly designed by empirical method. The three dimensional numerical model, based on the engineering practice, is analyzed by FLAC3D. In this paper, an improved LDP (longitudinal displacement profile) equation is proposed, which is more accurate in describing the convergence of tunnel before excavation face reaching. Then, a methodology is presented to determine the installation location of initial support in a more efficient and effective way. By simulating the process of excavation load releasing, the appropriate time for installing initial support is when the evolution of surrounding rock displacement has a tendency to increase rapidly, namely that the stability of rock mass arrives at the critical state. The mathematical relationship between the convergence of tunnel and the relative location to tunnel face can be established by fitting monitoring data with the improved LDP equation. Substituting the critical tunnel convergence into the LDP relationship, the corresponding installation location of initial support will be calculated. Meanwhile, several schemes with diverse geological conditions are carried out to validate the improved LDP and the methodology.

Output Feedback Stabilization for an ODE Coupled with a Wave Equation with Variable Coefficients

Yan Xing Zhao,Jun Jun Liu,Yan Na Jia 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.2

In this paper, we are concerned with the output feedback problem for coupled ODE-wave systems subject to spatially-varying coefficients. An original transformation is designed to turn the wave equation into an equation of the same type with constant coefficient and low order term. Taking advantage of the backstepping method, a state observer is constructed by non-collocated boundary displacement and velocity measurement. Output feedback on the based of the observer output feedback is then constructed, which makes use of the backstepping method to make the system exponentially stable. Finally, we demonstrate the well-posed and the exponential stability of the closed-loop system.