• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.19 no.39
• /
• pp.9-18
• /
• 1996

Many algorithms have been developed for optimizing the asymmectric traveling salesman problem known as a representative NP-Complete problem. The most efficient ones of them are branch and bound algorithms based on the subtour elimination approach. To increase efficiency of the branch and bound algorithm. number of decision nodes should be decreased. For this the minimum bound that is more close at the optimal solution should be found or an effective bounding strategy should be used. If the optimal solution has been known, we may apply it usefully to branching. Because a good feasible solution should be found as soon as possible and have similar features of the optimal solution. By the way, the upper bound solution in branch and bound algorithm is most close at the optimal solution. Therefore, the upper bound solution can be used instead of the optimal solution and information of which can be applied to new branching criteria. As mentioned above, this paper will propose an effective branching rule using the information of the upper bound solution in the branch and bound algorithm. And superiority of the new branching rule will be shown by comparing with Bellmore-Malone's one and carpaneto-Toth's one that were already proposed.

• Proceedings of the Korean Society for Language and Information Conference
• /
• 2001.06a
• /
• pp.199-225
• /
• 2001

The main goal of this paper is to investigate and compare English, German and Korean non-head-bound-intensifiers such as English ‘x-self’, German ‘selbst’, and Korean ‘susulo, casin’. That is, this paper is mainly concerned with the semantic domain where the respective contributions of the expressions in question overlap. The phenomenon under discussion with the label “intensifiers” is regarded as universal, which provides the ground of the comparative/contrastive or semi-cross-linguistic study of this paper. Not only the semantic concept of intensification by these expressions but also the combination of grammatical features or syntactic behaviours thereof seem to have highly invariant common denominators among the wide varieties of languages, even if they come from apparently different language families. In comparing English, German and Korean intensifiers, this paper is interested in the more general features of the expressions in question rather than some language-specific idiocyncracies. Intensifiers work similarly not only in English and German, but also in Korean. Each of three languages under investigation provides some sort of a safegard against confusing instances and misleading judgements on the issues under discussion. Morphologically, however, English expressions in question agree with their rele-vant NP in number, gender and person. Whereas German and Korean counterparts do not have such specific morphological properties. Intensifiers in their non-head-bound-use are subject-oriented, just as in their head-bound use. Non-head-bound-intensifiers differ from head-bound-intensifiers mostly in their syntactic behaviours or distributional properties, whereas they share the semantic domain “intensification” regarding relevant subject-NP. They introduce an ordering and distinguish center and periphery, and ‘self-involvement (directness of involvement)’seems a additional possible characterisation of the relevant dimension of these intensifiers in common. An assertion of identity also can be reg

• Steel and Composite Structures
• /
• v.5 no.1
• /
• pp.1-15
• /
• 2005

Important characteristics of the previously proposed reduced stiffness method and a summery of its design curves for the buckling of the axially loaded sandwich cylindrical shells is presented. Comparison of the lower bound obtained with FEM analysis with that from the reduced stiffness analysis shows that the proposed reduced stiffness method can provide safe lower bounds for the buckling of geometrically imperfect, axially loaded sandwich cylindrical shells. One of the attractive features of the reduced stiffness elastic lower bound analysis is that it provides safe estimates of buckling loads that do not depend on the specification of the precise magnitude of the imperfection spectra. As a result, designers can readily apply this method without being worried about possible geometrical imperfections that might be generated during fabrication and construction of sandwich cylindrical shells.

• International journal of advanced smart convergence
• /
• v.7 no.4
• /
• pp.19-26
• /
• 2018

One of the distinct features of Wireless Sensor Networks (WSNs) is duty cycling mechanism, which is used to conserve energy and extend the network lifetime. Large duty cycle interval introduces lower energy consumption, meanwhile longer end-to-end (E2E) delay. In this paper, we introduce an energy consumption minimization problem for duty-cycled WSNs. We have applied Q-learning algorithm to obtain the maximum duty cycle interval which supports various delay requirements and given Delay Success ratio (DSR) i.e. the required probability of packets arriving at the sink before given delay bound. Our approach only requires sink to compute Q-leaning which makes it practical to implement. Nodes in the different group have the different duty cycle interval in our proposed method and nodes don't need to know the information of the neighboring node. Performance metrics show that our proposed scheme outperforms existing algorithms in terms of energy efficiency while assuring the required delay bound and DSR.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.26 no.2
• /
• pp.83-86
• /
• 2013

The optical properties of ZnO thin film have been studied using photoluminescence(PL) spectroscopy with the change of sample temperatures from 10 K to 290 K. The spectrum at 10 K showed the characteristic emission lines of ZnO which were as follows: free exciton(FX) at 3.369 eV, neutral donor-bound exciton($D^0X$) at 3.360 eV, two electron satellite(TES) at 3.332 eV, $D^0X$-1LO at 3.289 eV, and donor-acceptor pair(DAP) transiton at 3.217 eV. From the spectral evolution with temperatures, two features could be identified as temperature went higher: (1) the bound excitons changed gradually into free excitons, (2) DAP turned into free electron-acceptor transition(e,$A^0$). The PL intensity of free exciton increased with the increase of temperatures, which was accompanied by the decrease of the intensity of bound excitions and bound excition-related transitons such as TES and $D^0X$-1LO. At 80 K DAP transition disappeared, while (e,$A^0$) transition started to appear at 30 K.

• 제어로봇시스템학회:학술대회논문집
• /
• 1989.10a
• /
• pp.984-986
• /
• 1989

101 coding scheme, one of sliding block coding techniques, provides practically attractive features in some compression applications for image sources such as facsimile. This paper presents a new simple model of 101 coder. The results show that the entropy of the output of the 101 coder can be reduced close to the rate distortion bound of a binary first-order markov source.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.8 no.4
• /
• pp.1368-1389
• /
• 2014

Three-dimensional multiple-input multiple-output (3D MIMO) and large-scale MIMO are two promising technologies for upcoming high data rate wireless communications, since the inter-user interference can be reduced by exploiting antenna vertical gain and degree of freedom, respectively. In this paper, we derive the achievable sum rate of 3D MIMO systems employing zero-forcing (ZF) receivers, accounting for log-normal shadowing fading, path-loss and antenna gain. In particular, we consider the prevalent log-normal model and propose a novel closed-form lower bound on the achievable sum rate exploiting elevation features. Using the lower bound as a starting point, we pursue the "large-system" analysis and derive a closed-form expression when the number of antennas grows large for fixed average transmit power and fixed total transmit power schemes. We further model a high-building with several floors. Due to the floor height, different floors correspond to different elevation angles. Therefore, the asymptotic achievable sum rate performances for each floor and the whole building considering the elevation features are analyzed and the effects of tilt angle and user distribution for both horizontal and vertical dimensions are discussed. Finally, the relationship between the achievable sum rate and the number of users is investigated and the optimal number of users to maximize the sum rate performance is determined.

• Journal of Conservation Science
• /
• v.22
• /
• pp.109-120
• /
• 2008

Understanding the whole knowledge of ceramics is essential for a person in charge of conservation of ceramics since their methods of manufacturing or materialistic features have very close relationship with their damaging process. Also, various executions of repair and restoration dealing with any damage in use have to be looked into. The information attained through those studies finds damaging causes of ceramics, which becomes a critical element when choosing a proper conservation treatment method and utilizes as indispensable data for permanent preservation. As part of scrutinizing materials of repair and restoration, this study examines the purpose, date, and the constituents of the materials used in metal bound rims adhered to the brim of ceramics. Among the subjected ceramics, the metal bound rims possible to scientific analysis were gone through element analyses with Portable ${\bullet}\"{I}$-XRF Spectrometer and SEM-EDS while the ingredients of the ceramics difficult to analyze were inferred by eye inspection of exhibition catalogues. The results of this study confirm that metal bound rims consisted of diverse materials were adhered to the brim of ceramics.

• Proceedings of the Korean Information Science Society Conference
• /
• 2001.04b
• /
• pp.151-153
• /
• 2001

Feature Simplification is an essential method for multiple representations of spatial features in GIS. However, spatial features re various, complex and a alrge size. Among spatial features which describe spatial information. linear feature is the msot common. Therefore, an efficient linear feature simplification method is most critical for spatial feature simplification in GIS. This paper propose an original method, by which the problem of linear feature simplification is mapped into the signal processing field. This method avoids conventional geometric computing in existing methods and exploits the advantageous properties of wavelet transform. Experimental results are presented to show that the proposed method outperforms the existing methods and achieves the time complexity of O(n), where n is the number of points of a linear feature. Furthermore, this method is not bound to two-dimension but can be extended to high-dimension space.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1995.10a
• /
• pp.633-637
• /
• 1995

Numerical calculation tool for forging of gear-like components based on kinematically admissible velocity fields for upper bound method applicable to various deformation features of workpiece in forging processes were suggested. Each one of them deals with unidirectional flow of metal on dies, such as external involute spur gear, sequare spline, internal serrations. A complex calcuation tool of gear-like component forging process was built up by combining these kinematically velocity fields. In this paper, the workpiece with both external and internal teeth is divided into two parts. The deformation of each part is analyzed simultaneously using numerical calculation tool form combined kinematically admissible velocity field. The experimental set-up was installed in a 200 ton hydraulic press. As a result, each kinematically admissible velocity field could be combined with other and the calculated solution are useful to predict the capacity of forging equipment.