• Journal of the Korean Society for information Management
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• v.40 no.4
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• pp.1-31
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• 2023

This study conducted user experience evaluation by introducing various text mining techniques along with topic modeling techniques for mobile menstrual cycle measurement applications that are closely related to women's health and analyzed the results by combining them with a honeycomb model. To evaluate the user experience revealed in the menstrual cycle measurement application review, 47,117 Korean reviews of the menstrual cycle measurement application were collected. Topic modeling analysis was conducted to confirm the overall discourse on the user experience revealed in the review, and text network analysis was conducted to confirm the specific experience of each topic. In addition, sentimental analysis was conducted to understand the emotional experience of users. Based on this, the development strategy of the menstrual cycle measurement application was presented in terms of accuracy, design, monitoring, data management, and user management. As a result of the study, it was confirmed that the accuracy and monitoring function of the menstrual cycle measurement of the application should be improved, and it was observed that various design attempts were required. In addition, the necessity of supplementing personal information and the user's biometric data management method was also confirmed. By exploring the user experience (UX) of the menstrual cycle measurement application in-depth, this study revealed various factors experienced by users and suggested practical improvements to provide a better experience. It is also significant in that it presents a methodology by combines topic modeling and text network analysis techniques so that researchers can closely grasp vast amounts of review data in the process of evaluating user experiences.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.1
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• pp.131-143
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• 1996

In this paper, we propose the improved structure of fully interconnected ATM Switch to develop the small sized switch element and represent practical implementation of switch network. As the part II of the full study about structure and implementation of fully interconnected ATM Switch, this paper especially describes the implementation of an ATM switching element with 8 input port and 8 output port at 155 Mbits/sec each. The single board switching element is used as a basic switching block in a small sized ATm switch for ATM LAN Hub and customer access node. This switch has dedicated bus in 12 bit width(8 bit data + 4 bit control signal) at each input and output port, bit addressing and cell filtering scheme. In this paper, we propose a practical switch architecture with fully interconnected buses to implement a small-sized switch and to provide multicast function withoutany difficulty. The design of switching element has become feasible using advanced CMOS technology and Embedded Gate Array technology. And, we also represent Application Specific Integrated Circuit(ASIC) of Switch Output Multiplexing Unit(SOMU) and 12 layered Printed Circuit Board for interconnection network of switch.

• Journal of the Institute of Convergence Signal Processing
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• v.16 no.3
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• pp.102-107
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• 2015

Personal information leakage is one of the great recent issues, which can be caused by hacking or censorship when a messenger program is used between user groups in Android-based smartphones, In order to solve these problems, companies generally apply complex security procedures inside the messenger, but which degrade the efficiency of work. This paper proposes a method which can improve work efficiency and strengthen security by allowing only the clients that can access a particular AP, and implementing a closed messenger group. The proposed method is validated by implementing on the Android-based smartphones.

• Journal of The Korean Astronomical Society
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• v.35 no.1
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• pp.41-57
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• 2002

We have written a code called QDM_sca, which numerically solves the problem of radiative transfer in an anisotropically scattering, spherical atmosphere. First we formulate the problem as a second order differential equation of a quasi-diffusion type. We then apply a three-point finite differencing to the resulting differential equation and transform it to a tri-diagonal system of simultaneous linear equations. After boundary conditions are implemented in the tri-diagonal system, the QDM_sca radiative code fixes the field of specific intensity at every point in the atmosphere. As an application example, we used the code to calculate the brightness of atmospheric diffuse light(ADL) as a function of zenith distance, which plays a pivotal role in reducing the zodiacal light brightness from night sky observations. On the basis of this ADL calculation, frequent uses of effective extinction optical depth have been fully justified in correcting the atmospheric extinction for such extended sources as zodiacal light, integrated starlight and diffuse galactic light. The code will be available on request.

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.1
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• pp.19-28
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• 2000

The purposes of this study are two folds: a) to introduce conjoint choice model to research the choice behavior of theme park users, and b) to suggest the strategies to strengthen the competitiveness of theme parks. The major four theme parks in Seoul metropolitan areas were selected as study areas. A leading polling agency was employed to select 432 respondents by probability sampling and to conduct face-to-face interview. Both alternative generating and choice set generating fractional factorial design were conducted simultaneously to meet the necessary and sufficient conditions for calibration of the conjoint choice model. Dummy coding was used to represent the attribute levels, and the alternative-specific model was calibrated. The goodness-of-fit of the model was quite satisfactory($\rho$$^2$=0.47950), and most parameters values had to expected sign and magnitude. Car was preferred transport mode to shuttle bus for visiting theme parks ; however the most ideal attribute levels only were estimated significantly. Most attribute levels of shuttle bus were estimated significantly except the Dream Land, which is the least attractive park among study areas. Simulation results showed that the shuttle bus was a mode worth providing to switch the current car dominant visiting pattern of theme parks, which will be one the effective strategies to attract more patrons, especially for potential users adjacent to parks. Several ideals were suggested for future researches, in terms of utilization of more general utility function and new base alternative, and inclusion of more salient attributes such as constraints in the model.

• Journal of the Society of Naval Architects of Korea
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• v.43 no.5 s.149
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• pp.586-596
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• 2006

A 3-dimensional FDLB model with additional internal degree of freedom is applied for diatomic gases such as air, in which an additional distribution function is introduced. Direct simulations of aero-acoustic by using the applied model and scheme are presented. Speed of sound is correctly recovered. As typical examples, the Aeolian tone emitted by a circular column is successfully simulated even very low Mach number flow. Acoustic pressure fluctuations with the same frequency of the Karman vortex street compared with the pressure fluctuation around a circular column is captured. Full three-dimensional acoustic wave past a compact block like pentagon, furthermore, is also emitted in y direction as dipole like sound.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.4
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• pp.1579-1602
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• 2020

In the design of production system, buffer capacity allocation is a major step. Through polymorphism analysis of production capacity and production capability, this paper investigates a buffer allocation optimization problem aiming at the multi-stage production line including unreliable machines, which is concerned with maximizing the system theoretical production rate and minimizing the system state entropy for a certain amount of buffers simultaneously. Stochastic process analysis is employed to establish Markov models for repairable modular machines. Considering the complex structure, an improved vector UGF (Universal Generating Function) technique and composition operators are introduced to construct the system model. Then the measures to assess the system's multi-state reliability and structural complexity are given. Based on system theoretical production rate and system state entropy, mathematical model for buffer capacity optimization is built and optimized by a specific genetic algorithm. The feasibility and effectiveness of the proposed method is verified by an application of an engine head production line.

• Journal of the military operations research society of Korea
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• v.1 no.1
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• pp.111-129
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• 1975

U.S. Air Force Regulation 80-1 defines that a weapon system is composed of equipments, skills, and techniques, the composite of which ferns an instrument of combat. The complete weapon system includes all related facilities, equipments, materials, services, and personnels required for the operation of the system, so that the instrument of combat can be considered as a self-sufficient unit of striking power in its intended operational environment. Effectiveness of a weapon system can be expressed as a function of its liability, reliability and performance capability. Among these attributes which influence the weapon effectiveness, performance capability is considered to be the most critical factor for many weapon systems. In order to illustrate the application of the methodology of performance capability, a specific ease study on the effectiveness of Vulcan anti-air craft gun system is presented with special emphasis on hitting probability on moving targets, effects of artificial rounds dispersion, and several principles related to the deployment of the system. This thesis includes the thorough survey of the possibility of calculating the absolute value of hitting probability on moving targets, indicates that the effects of artificial rounds dispersion increase the value of probability only when the total number of rounds fired within fire range exceeds a certain critical number, and suggests that concentrated guns deployment is better than scattered deployment in order to obtain higher probability and lower average amount of rounds if it is assumed that the effects of counter-attack from enemy threats are not serious.

• Journal of the Korean Institute of Intelligent Systems
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• v.6 no.2
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• pp.13-21
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• 1996

The necessity and usefulness of higher-order neural networks have been well-known since early days of neurocomputing. However the explosive number of terms has hampered the design and training of such networks. In this paper we present an evolutionary learning method for efficiently constructing problem-specific higher-order neural models. The crux of the method is the neural tree representation employing both sigma and pi units, in combination with the use of an MDL-based fitness function for learning minimal models. We provide experimental results in classification and prediction problems which demonstrate the effectiveness of the method. I. Introduction topology employs one hidden layer with full connectivity between neighboring layers. This structure has One of the most popular neural network models been very successful for many applications. However, used for supervised learning applications has been the they have some weaknesses. For instance, the fully mutilayer feedforward network. A commonly adopted connected structure is not necessarily a good topology unless the task contains a good predictor for the full *d*dWs %BH%W* input space.

• Journal of Microbiology and Biotechnology
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• v.13 no.1
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• pp.57-63
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• 2003

Using fungal (Fusarium solani f. pisi) and bacterial (Pseudomonas mendocina) cutinases, the initial hydrolysis rate of p-nitrophenyl esters was systematically estimated for a wide range of enzyme and substrate concentrations using a 96-well microplate reader. Both cutinases exhibited a high substrate specificity; i.e. a high hydrolytic activity on p-nitrophenyl butyrate (PNB), yet extremely low activity on p-nitrophenyl palmitate (PNP). When compared to the hydrolysis of PNB and PNP by other hydrolases [lipases and esterases derived from different microbial sources, such as bacteria (Pseudomonas cepacia, Psedomonas furescens, Baciilus stearothermophilus), molds (Aspeillus niger, mucor miehei), and yeasts (Candida rugosa, Candida cylindracea)], the above substrate specificity would seem to be a unique characteristic of cutinases. Secondly, the hydrolytic activity of the cutinases on PNB appeared much faster than that of the other hydrolytic enzymes mentioned above. Furthermore, the current study proved that even when the cutinases were mixed with large amounts of other hydrolases (lipases or esterases), the Initial hydrolysis rate of PNB was determined only by the cutinase concentration for each PNB concentration. This property of cutinase activity would seem to result from a higher accessibility to the substrate PNB, compared with the other hydrolytic enzymes. Accordingly, these distinct properties of cutinases may be very useful in the rapid and easy isolation of various natural cutinases with different microbial sources, each of which may provide a novel industrial application with a specific enzymatic function.