• Korean Journal of Mathematics
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• v.14 no.2
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• pp.249-258
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• 2006

The weakened forms of the (${\theta},s$)-continuous function are introduced and their basic properties are investigated in concern with the other weakened continuous function. The open property of a function and the extremal disconnectedness of the spaces are crucial tools for the survey of these functions.

• Communications of the Korean Mathematical Society
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• v.27 no.1
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• pp.201-205
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• 2012

A space X is cs-starcompact if for every open cover $\mathcal{U}$ of X, there exists a convergent sequence S of X such that St(S, $\mathcal{U}$) = X, where $St(S,\mathcal{U})\;=\; \cup\{U{\in}\mathcal{U}:U{\cap}S{\neq}\phi\}$. In this paper, we prove the following statements: (1) There exists a Tychonoff cs-starcompact space having a regular-closed subset which is not cs-starcompact; (2) There exists a Hausdorff cs-starcompact space with arbitrary large extent; (3) Every Hausdorff centered-Lindel$\ddot{o}$f space can be embedded in a Hausdorff cs-starcompact space as a closed subspace.

• Journal of the Korean Society for information Management
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• v.35 no.4
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• pp.77-106
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• 2018

Prior to the concrete and practical use of closed schools, this study was designed to identify trends in the use of closed schools, and the possibility and direction of the library's use of closed schools based on the status of closed schools and use cases. As a result of the case analysis, the building of libraries using closed schools can be reborn as libraries with different characteristics from general public libraries, such as providing complex cultural spaces, eco-friendly spaces, and local community places. In addition, based on the results of the study, future direction of library closure is suggested as follows: Provide local economic contribution and local revitalization opportunities, life-friendly and friendly space for local residents, recycling space linked with elderly welfare, care service, urban to rural Immigrants, creation of added value and creation of local business using closed schools, environment-friendly space, recycling as a complex community center, recycled into a space that meets and complements local needs.

• Journal of the Korea Society of Computer and Information
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• v.22 no.11
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• pp.49-55
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• 2017

Recently, for safety of people, there are proposed so many technologies which detect density of people at the specific place or space. The representative technology for crowd density estimation was using image analysis method from CCTV images. However, this method had a weakness which could not be used and which's accuracy was lower at the dark or smog space. Therefore, in this paper, to solve this problem, we proposed a user density estimation system at closed space using high frequency and smart device. The system send inaudible high frequencies to smart devices and it count the smart devices which detect the high frequencies on the space. We tested real-time user density with the proposed system and ten smart devices to evaluate performance. According to the testing results, we confirmed that the proposed system's accuracy was 95% and it was very useful. Thus, because the proposed system could estimate about user density at specific space exactly, it could be useful technology for safety of people and measurement of space use state at indoor space.

• Communications of the Korean Mathematical Society
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• v.30 no.4
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• pp.493-504
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• 2015

The aim of this paper is to present some properties of sT-continuous functions. Moreover, we obtain a characterization and preserving theorems of semi-compact, S-closed and s-closed spaces.

• Honam Mathematical Journal
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• v.35 no.4
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• pp.707-716
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• 2013

The present paper consists of two parts. Since the recent paper [4] proved that an Alexandroff $T_0$-space is a semi-$T_{\frac{1}{2}}$-space, the first part studies semi-open and semi-closed structures of the Khalimsky nD space. The second one focuses on the study of a relation between the LS-property of ($SC^{n_1,l_1}_{k_1}{\times}SC^{n_2,l_2}_{k_2}$, k) relative to the simple closed $k_i$-curves $SC^{n_i,l_i}_{k_i}$, $i{\in}\{1,2\}$ and its normal k-adjacency. In addition, the present paper points out that the main theorems of Boxer and Karaca's paper [3] such as Theorems 4.4 and 4.7 of [3] cannot be new assertions. Indeed, instead they should be attributed to Theorems 4.3 and 4.5, and Example 4.6 of [10].

• Journal of The Korean Digital Architecture Interior Association
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• v.10 no.3
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• pp.39-46
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• 2010

Recently, in rural areas have been occurred closed school due to reduce children of people who consider educational environment. In July 2009 statistic, Closed school are ut to 3,348; sale process(61%), lease(25%), neglect(14%). Closed school are not only local community education, but also to act as cultural and historical role. First of all, it will be utilized public facilities as well as welfare facilities for local residents. In this study suggests the welfare facility where is remodelled as good case so that it will use as a data when closed school need remodeling. The main contents is as follows; it is set the slope next to the school building, a classroom is remodelled 2 triple rooms which are installed Ondol and a toilet, teacher's room is converted into the canteen, corridors are converted into the kitchen. Having good condition in the area, close school is appropriate to use welfare facility and also effective to convert teacher's space into normal space, canteen, kitchen. Finally, developed 2~5 composition type of elderly facility.

• Communications of the Korean Mathematical Society
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• v.32 no.1
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• pp.175-181
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• 2017

In this paper, we introduce a notion of cleanly covered topological spaces along with two strong separation axioms. Some properties of cleanly covered topological spaces are obtained in term of maximal open sets including some similar properties of a topological space in term of maximal closed sets. Two strong separation axioms are also investigated in terms of minimal open and maximal closed sets.

• Journal of Chest Surgery
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• v.18 no.4
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• pp.822-834
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• 1985

Reexpansion of the lung is the most desirable method of filling the pleural space whether it`s contents may be, and closed thoracotomy connected to a water-seal drainage remains the basic therapeutic modality in the treatment of the problems of the pleural space. We usually used rubber mushroom tubes, size No. from 16 to 34 Fr., and performed closed thoracotomy after preliminary thoracentesis to determine the exact depending position. Author reviewed 576 cases of closed thoracotomy which were performed in the Department of Thoracic and Cardiovascular Surgery, Pusan National University Hospital, since Jan., 1980 to June, 1984. The results were as follows: 1. The age distribution was 10 days to 76 years old and mean age of the patients was 36.6 year, and the most prevalent age group was twenties, and sex predisposition was male dominant, 86.9%. 2. The most common etiologic disease group was pneumothorax and the most common etiologic disease was traumatic hemothorax. 3. Sites of tubing were predominantly at posterior axillary line, 7th intercostal space and midclavicular line, 2nd intercostal space even though frequent presence of free pleural space. The two sides, right and left difference of occurrence rate was more frequent at right side, 51.2%. 4. Usually the durations of tubing was less than 10 days, 52.6%, and the number of tubes used to the same patient concomitantly was one, 73.9%, and the time of tubing to the same patient was 1st, 83.6%. 5. The common symptom and sign were dyspnea, 50.0%, chest pain, 30.7%, cough, 10.7%, fever, 6.5%. Especially, fever and cough was the most common symptom and sign in pyogenic empyema, 59.3%. 6. The common etiologic lesions of pneumothorax were blebs and bullae, 73.3%, and of pyogenic empyema was pneumonia, 69.0%. 7. The complication rate of closed thoracotomy was 26.0%. Among these complications, infection was 44.7%, and intercostal neuralgia was 25.3%. 8. 70.9% of all patients recovered with only closed thoracotomy and the rest of patient needed additional some necessary managements such as open thoracotomy [Blebectomy, Resection, Pleurodesis, Decortication, Bleeding control], open drainage, thoracoplasty and so on to have successful results.

• Journal of the Korean earth science society
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• v.40 no.4
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• pp.353-381
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• 2019

The general world model for homogeneous and isotropic universe has been proposed. For this purpose, we introduce a global and fiducial system of reference (world reference frame) constructed on a (4+1)-dimensional space-time, and assume that the universe is spatially a 3-dimensional hypersurface embedded in the 4-dimensional space. The simultaneity for the entire universe has been specified by the global time coordinate. We define the line element as the separation between two neighboring events on the expanding universe that are distinct in space and time, as viewed in the world reference frame. The information that determines the kinematics of the geometry of the universe such as size and expansion rate has been included in the new metric. The Einstein's field equations with the new metric imply that closed, flat, and open universes are filled with positive, zero, and negative energy, respectively. The curvature of the universe is determined by the sign of mean energy density. We have demonstrated that the flat universe is empty and stationary, equivalent to the Minkowski space-time, and that the universe with positive energy density is always spatially closed and finite. In the closed universe, the proper time of a comoving observer does not elapse uniformly as judged in the world reference frame, in which both cosmic expansion and time-varying light speeds cannot exceed the limiting speed of the special relativity. We have also reconstructed cosmic evolution histories of the closed world models that are consistent with recent astronomical observations, and derived useful formulas such as energy-momentum relation of particles, redshift, total energy in the universe, cosmic distance and time scales, and so forth. The notable feature of the spatially closed universe is that the universe started from a non-singular point in the sense that physical quantities have finite values at the initial time as judged in the world reference frame. It has also been shown that the inflation with positive acceleration at the earliest epoch is improbable.