• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.4
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• pp.14-22
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• 2022

To reduce the weight of the car and ensure the safety of the driver while driving, the existing 440 MPa-class mounting bracket was treated at 590MPa to improve collision safety and secure the weight of the vehicle body. The following conclusions were drawn from the tensile test, forming analysis, and springback prediction. In the formability and springback analyses using FLD, it could be confirmed that bending was an essential process because the formability and flatness were much better when bending was added than when bending was not applied. Based on the research results, it was deduced that the mold design was necessary so that the molding was carried out at a strain rate of 20% or less for stable molding.

• Publications of The Korean Astronomical Society
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• v.39 no.2
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• pp.27-38
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• 2024

Line observations of young stellar objects (YSOs) at (sub)millimeter wavelengths provide essential information of gas kinematics in star and planet forming environments. For Class 0 and I YSOs, identification of Keplerian rotation is of particular interest, because it reveals presence of rotationally-supported disks that are still being embedded in infalling envelopes and enables us to dynamically measure the protostellar mass. We have developed a python library SLAM (Spectral Line Analysis/Modeling) with a primary focus on analyses of emission line data at (sub)millimeter wavelengths. Here, we present an overview of the pvanalysis tool from SLAM, which is designed to identify Keplerian rotation of a disk and measure the dynamical mass of a central object using a position-velocity (PV) diagram of emission line data. The advantage of this tool is that it analyzes observational features of given data and thus requires few computational time and parameter assumptions, in contrast to detailed radiative transfer modelings. In this article, we introduce the basic concept and usage of this tool, present an application to observational data, and discuss remaining caveats.

• Publications of The Korean Astronomical Society
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• v.27 no.4
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• pp.311-316
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• 2012

Lyman break Galaxies are galaxies selected in the rest-frame ultraviolet. But, one important and missing information for these Lyman break galaxies is the amount of dust attenuation. This is crucial to estimate the total star formation rate of this class of objects and, ultimately, the cosmic star formation density. AKARI, Spitzer and Herschel are therefore the major facilities that could provide us with this information. As part of the Herschel Multi-tiered Extragalactic Survey, we have began investigating the rest-frame far-infrared properties of a sample of more than 4,800 Lyman Break Galaxies in the GOODS-North fiels. Most LBGs are not detected individually, but we do detect a sub-sample of 12 objects at 0.7 < z <1.6 and one object at z = 2.0. The ones detected by Herschel SPIRE have redder observed NUV-U and U-R colors than the others, while the undetected ones have colors consistent with average LBGs at z > 2.5. We have analysed their UV-to-FIR spectral energy distributions using the code cigale to estimate their physical parameters. We find that LBGs detected by SPIRE are high mass, luminous infrared galaxies. They also appear to be located in a triangle-shaped region in the $A_{FUV}$ vs. $logL_{FUV}$ diagram limited by $A_{FUV}$ = 0 at the bottom and by a diagonal following the temporal evolution of the most massive galaxies from the bottom-right to the top-left of the diagram. In a second step, we move to the larger COSMOS field where we have been able to detect 80 Lyman break galaxies (out of ~ 15,600) in the far infrared. They form the largest sample of Lyman break galaxies at z > 2.5 detected in the far-infrared. We tentatively name them Submillimeter Lyman break galaxies (S-LBGs).

• Journal of Internet Computing and Services
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• v.16 no.3
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• pp.33-41
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• 2015

In this paper, the simplification procedure of Karnaugh Map, which is essential to design digital logic circuits, was implemented as web-based educational Java applets. The learners will be able to experience interesting learning process by executing the proposed Java applets. In addition, since the proposed Java applets were designed to contain educational technologies by step-by-step procedure, the maximization of learning efficiency can be obtained. The learners can make virtual experiments on the simplification of digital logic circuits by clicking on some buttons or filling out some text fields. Furthermore, the Boolean expression and its schematic diagram occurred in the simplification process will be displayed on the separate frame so that the learners can learn effectively. The schematic diagram enables them to check out if the logic circuit is correctly connected or not. Finally, since the simplification algorithm used in the proposed Java applet is based on the modified Quine-McCluskey minimization technique, the proposed Java applets will show more encouraging result in view of learning efficiency if it is used as assistants of the on-campus offline class.

• Journal of the Korean association of regional geographers
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• v.12 no.5
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• pp.583-594
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• 2006

Relics are life traces of ancestors, and they are good data for giving an idea about space locations of that period. This study classifies relics according to their type, and for each classified group metrical analysis is carried out using GIS and triangle diagram. The criteria used for analysis of relics' locations are elevation, road accessibility and water accessibility. The analysis results show that every relic has its own distribution characteristics according to the time and the type. This means high possibility of approaching a geographical focus on relics distribution and location. While historical period was taking over prehistorical, relics locations moved from the points of great usage water supply possibility to the points of great traffic accessibility. Also, relics of the ruling class for each time period generally have good locations.

• Journal of KIISE
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• v.43 no.10
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• pp.1104-1114
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• 2016

Software is continuously changing during development and after development. When a change is required, it is difficult to precisely grasp the scope of impact intuitively. A systematic method is needed to accomplish the required change. The purpose of impact analysis on software change is to avoid missing any information by recognizing the ripple effect that the change might cause. This paper proposes a dynamic method that can easily identify the scope of change request by using the association between use-case scenarios and artifacts of UML modeling in object-oriented development environment. By using this approach, the scope of impact that the change might have on other components such as class diagram and sequence diagram in use-case scenarios can be identified by forward tracing. In addition, analysis of influence of possible further changes due to changes in other components can be identified iteratively through backward tracing. The results of this paper are not limited to impact analysis on artifacts and change type. They can also be used as basic guidelines during impact analysis for various change requests.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.6
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• pp.1567-1572
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• 2012

An IPC(instrument panel Cluster) is a useful device that provides driving information to the driver. The information includes the vehicle speed, RPM, mileage, etc. The traditional IPC has been mostly implemented with mechanical technique. According to increment of needs for the convenience of IPC by user, the IPC must provide graphical interface and efficient driving information. Also the user-friendly IPC is needed by drivers. Thus flexible and robust software structure and development methods are required in order to develop IPC. In this paper, we propose software architecture and design method for the IPC using modeling method. We use MVC model and UML to model software architecture because they have flexible and robust characteristics. We can develop the various forms of information screen by separating views from model by using state diagram and class diagram in UML. Through this, the cost saving and ease of maintenance can be expected. The development time and cost can be reduced by using proposed method.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.6
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• pp.1321-1326
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• 2012

An IPC(instrument panel Cluster) is a useful device that provides driving information to the driver. The information includes the vehicle speed, RPM, mileage, etc. The traditional IPC has been mostly implemented with mechanical technique. According to increment of needs for the convenience of IPC by user, the IPC must provide graphical interface and efficient driving information. Also the user-friendly IPC is needed by drivers. Thus flexible and robust software structure and development methods are required in order to develop IPC. In this paper, we propose software architecture and design method for the IPC using modeling method. We use MVC model and UML to model software architecture because they have flexible and robust characteristics. We can develop the various forms of information screen by separating views from model by using state diagram and class diagram in UML. Through this, the cost saving and ease of maintenance can be expected. The development time and cost can be reduced by using proposed method.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.1
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• pp.167-174
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• 2017

Earthwork is to level or excavate the ground to provide a space for installing structures. A large number of construction equipment such as excavators, dozers, and dump trucks are put into the earthwork operation. The equipment operators need to constantly communicate with each other during the operation. In the earthwork operation, therefore, the process should be analyzed on the equipment operation to improve the effectiveness of communication. The objective of this study is to understand the earthwork process, and improve the effectiveness of data interface by adopting the smart glass technology. In the study, the general process of earthwork is modeled using a process diagram. The data that is generated during the process is modeled using a class diagram. A database is developed to store and reuse the data. The smart glass technology is adopted to develop a data interface during the earthwork operation. The result of the prototype showed that the technology can improve the data interface during excavation overcoming the shortcomings of hand or sound signals.

• Journal of Korean Society of Forest Science
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• v.34 no.1
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• pp.21-30
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• 1977

Japanese larch (Larix leptolepis) is one of main timber species in Korea that could find much plantation and growing stands on all over the country. It is thought to be in meaningful that a guiding diagram for density control of Japanese larch stands is made to estimate easily the density conditions in the quantitaive, ecological and economic viewpoint. Sample plots for this study are selected from the stands that have not been thinned in recent years, and mean height, mean diameter, dominant height, tree numbers per hectare and stem volume of mean tree are calculated from the each sample plots among total 165 plots In this study, especially, the theory of slenderness of mean tree are applied, that have been identified through the results of the spacing trial. Relative growth characteristics of this species are calculated from the general logistic curve and its formula is $Y=ax^b$. Relatwion between the measured items are found out as follows: 1. Relation between the mean height and tree numbers per hectare by slender class is showing the high correlation as table 1 and fig. 2, and between mean diameter and tree numbers per hectare is also high correlation as table 1 and fig 3. 2. The stem volume can be correctly estimated from height in case that slender class may be known, as showing in table 3 and fig. 4. 3. The stem volume can be more correctly estimated from the relation with $D^2H$ as formula, $Log_e\;V=0.9569\;Log_eD^2H-9.8431$, and relation between stem volume of single tree or volume per hectare and tree numbers per hectare are as following formulas: $Log_e$ stem volume=9.5026-1.6800 $Log_e$ tree numbers per hectare $Log_e$ stem volume per hectare=9.4911-0.6784 $Log_e$ tree numbers per hectare. Stem volume of mean tree, tree numbers per hectare and stem volume per hectare correspond to the mean tree height are calculated to slender class as table 5, 6, 7. Through the above steps, the diagram for density control of Japanese larch are produced as fig. 9. It is thought that this diagram could be applied to control the density of Japanese larch stands.