• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.11a
• /
• pp.277-278
• /
• 2008

Orthorhombic $LiMnO_2$(o-$LiMnO_2$) has attracted public attentions as a cathode materials of Lithium ion battery because it has low cost and high theoretical discharge capacity of 285mAh $g^{-1}$. In our study, o-$LiMnO_2$ is synthesized by quenching method. To verify their phase structure, X-ray diffraction is accomplished. Test cells are assembled to check electrochemical characteristics using acquired o-$LiMnO_2$ cathode and carbon anode. Charge/Discharge cycling was carried out for 50cycles. And impedance was measured at 1, 2, 5, 10, 30, 50cycle. During cycle test, the max discharge capacity was recorded 139mAh $g^{-1}$ at 10cycle.

• Proceedings of the Korean Society For Composite Materials Conference
• /
• 2003.10a
• /
• pp.123-126
• /
• 2003

This paper describes the development procedure for Tail-Fan system which has the role of anti-torque and yaw control in helicopter. A detailed design of Tail-Fan system was done and structural analysis also was done. After finishing detailed design, Detailed drawings were generated for manufacture. Through detailed design and manufacture, required techniques were achieved for helicopter development. After validation through performance and stability test, acquired techniques will be applied to development of Korea Multi-role Helicopter(KMH) which will be launched

• Proceedings of the KIEE Conference
• /
• 1997.11a
• /
• pp.19-21
• /
• 1997

This paper treated a new method that generates the dipole magnetic field for high speed machines by using Halbach array, which was suggested by Klaus Halbach. The Halbach array can produce the various field distribution without magnetic materials. Therefore, the iron losses can be reduced. This paper presented the magnetic characteristics on both linear and cylindrical Halbach array. And the Halbach array for dipole field was manufactured with Nd-Fe-B magnets having 1.17(T), the measured flux density was compared the theoretical values acquired by three dimensional FEM analysis. Finally, the magnetic characteristics of Halbach array were compared with those of other conventional dipole field systems.

• Smart Structures and Systems
• /
• v.1 no.3
• /
• pp.257-266
• /
• 2005

In Lamb wave detection of damages in smart structures, the excitation pulse is usually designed as a narrow band burst wave for the convenience of analysis and recognition. However, the wideband excitation can excite more modes in plate/shell structure and thus provides extra information for changes of the structure. This paper presents a method that can extract information in wideband Lamb wave signals. By transforming the detected signals into various sub-frequency band, the measured signal can be converted to its equivalences of narrow band excitations, therefore, the information in different frequency bands can be acquired from a single test and in the same time the complicity of wideband signal can be simplified. Some test results are provided to verify this method.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2015.05a
• /
• pp.221-222
• /
• 2015

Since the input data such as types and quantities of materials cannot be acquired during the planning and designing phases, it is difficult to estimate the carbon emissions from the construction phase. As the materials are closely related to the building usages, an approximate estimation by the usages can be suggested. However, before confirming the estimation, the difference test among the carbon emissions of the building usages should be implemented. This study executed t-test or Mann-Whitney test between apartments and schools. The result of the study statistically verified the significant difference between the carbon emissions of apartments and schools.

• Korean Institute of Interior Design Journal
• /
• no.39
• /
• pp.20-27
• /
• 2003

The purpose of this study is to provide a practical guide for selecting architectural artwork and analyze relationship between artwork and interior space & facade. The problems with many outdoor artwork did not make the characteristics of the specific environment and did not form a big flow in the urban contextualism. Choosing the artwork, architectural environment for artwork is very much part of the designers' task. When artwork is to be specifically acquired for a particular projects, designer and client must work together to make choices and plan placement. The data are collected through evaluation surveys of college students and graduate students majoring in interior architecture & design, and analyzed by using SPSS-WIN program to find the major characterized factors. It is concluded that architectural artwork should be constituted with nine major factors of interior space - theme/scale, situation/contemporay accord, finished materials harmony, line/two-three dimensional form, proportion/rhythm, sequence, natural/artificial form, abstract/reality expression, originality - and eight major factors of facade - situation, abstract/reality expression, finished materials harmony, theme/sequence, natural/artificial form, proportion/rhythm, static/dynamic expression, originality/. contemporay accord.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.24 no.6
• /
• pp.449-457
• /
• 2011

Effect of pump combinations on the vacuum characteristics of vacuum system was simulated for optimum design of system. In this investigation, the feasibility of modelling mechanism for VacSimMulti simulator was proposed. Simulation results of various pumping combinations showed the possibilities and reliabilities of simulation for the performance of vacuum system in specific semiconductor processing. Simulation of roughing pump presented the expected pumping behaviors based on commercial specifications of employed pumps. Application of booster pump exhibited the high pumping efficiency for middle vacuum range. Combinations of optimum backing pump for diffusion and turbo vacuum system were obtained. And, the predictable characteristics of process application of both simulated systems were also acquired.

• Transactions of Materials Processing
• /
• v.33 no.2
• /
• pp.87-95
• /
• 2024

The current study aims to prove that high-speed forming has better formability than conventional low-speed forming. Experimentally, the quasi-static forming limit diagram was obtained by Nakajima test, and the dynamic forming limit diagram was measured by electrohydraulic forming. For the experiments, the LS-DYNA was used to create the optimal specimen for electrohydraulic forming. The strain measurement was performed using the ARGUS, and comparison of the forming limit diagrams confirmed that EHF showed better formability than quasi-static forming. Theoretically, the Marciniak-Kuczynski model was used to calculate the theoretical forming limit. Swift hardening function and Cowper Symonds model were applied to predict the forming limits in quasi-static and dynamic status numerically.

• Education of Primary School Mathematics
• /
• v.11 no.1
• /
• pp.39-57
• /
• 2008

The purpose of this study is to affirm what influences the lessons applied by reorganizing the ratio-graph unit of level 6-A on the basis on Realistic Mathematics Education(RME) give on mathematical scholastic achievements and mathematical preferences.In order to achieve the purpose of this study, the experimental study was exerted by making two classes of 6 grades in J elementary school located in Gumi city, Gyeongbuk province as subjects. In this study, test of degree of the mathematics learning ability of student, multiple-choice test and descriptive test of the learning dispositions of student were exerted and the results were t-test officially. The results and the conclusions of this study were as follows: First, the results acquired by officially t-test the levels of the mathematics learning ability of student of the group taught by lessons according to the teaching materials reorganized on the basis of RME and the group taught by lessons according to the 7th curriculum show a meaningful difference(p=.007). This means that the lessons according to the teaching materials reorganized on the basis of RME showed meaningful influences on the improvement of degree of the mathematics learning ability of student. Second, the results acquired by officially t-test the learning dispositions of student multiple-choice test of the group taught by lessons according to the teaching materials reorganized on the basis of RME and the group taught by lessons according to the 7th curriculum show a meaningful difference. Especially in the factors of 'mathematical will'(p=.017) and 'mathematical value'(p=.029) were meaningful differences. Also in the descriptive test of the learning dispositions of student, the experimental class showed that it had the potential possibility to have more positive attitudes meaningfully in comparison with the compared class. This means that the lessons according to the teaching materials reorganized on the basis of RME showed meaningful influences on the learning dispositions of student.

• 한국호스피스완화의료학회:학술대회논문집
• /
• 2004.07a
• /
• pp.103-105
• /
• 2004

Every one experiences death one day, however no one can hows exactly what it is because people can not experience death until it comes, it is therefore impossible to judge correctly on the phenomenon of the death. On the whole, man experiences indirect death through the mass communications such as TV drama, fiction, magazine etc because those methods can easily access by every one. In addition to this, people usually acquire the negative awareness of death through the dramatic change of story like dying of cancer for dramatic effect by giving scare and fear to the cancers. The purpose of this study is to provide basic information on the spiritual care that enables the facing death patients to accept death as a part of life and divert hope from scare about after death by comparing and analyzing of two aspects of death meaning i.e, Korean fiction and the end stage cancer patients. Additionally, for medical staff to understand the facing death cancer patients by making to aware patients correctly and provide the better quality of care. The study was performed from September 28, 2002 to February, 28, 2003. The materials of this study were collected by direct data obtained from observation, interviews, note and diary of end stage of cancer patients and written materials acquired from Korean contemporary fiction. Participants of this study were 4 end stage cancer patients including 2 lung cancer patients, 1 liver cancer patient and 1 esophagus cancer patient. The methodology used in this study was divided into two types; Huberman & Miles methodology was used for fiction to find and categorize subject, and Colaizzi, one of phenomenological methodology was used for end stage cancer patients to find the major meaning, subject and categorization. Every one experiences death one day, however no one can knows exactly what it is because people ran not experience death until it comes, it is therefore impossible to judge correctly on the phenomenon of the death. On the whole, man experiences indirect death through the mass communications such as TV drama, fiction, magazine etc because those methods can easily access by every one. In addition to this, people usually acquire the negative awareness of death through the dramatic change of story like dying of cancer for dramatic effect by giving scare and fear to the cancers. The purpose of this study is to provide basic information on the spiritual care that enables the facing death patients to accept death as a part of life and divert hope from scare about after death by comparing and analyzing of two aspects of death meaning i.e, Korean fiction and the end stage cancer patients. Additionally, for medical staff to understand the facing death cancer patients by making to aware patients correctly and provide the better quality of care. The study was performed from September 28, 2002 to February, 28 2003. The materials of this study were collected by direct data obtained from observation, interviews, note and diary of end stage of cancer patients and written materials acquired from Korean contemporary fiction. Participants of this study were 4 end stage cancer patients including 2 lung lancer patients, 1 liver cancer patient and 1 esophagus cancer patient. The methodology used in this study was divided into two types; Huberman & Miles methodology was used for fiction to find and categorize subject, and Colaizzi, one of phenomenological methodology was used for end stage cancer patients to find the major meaning, subject and categorization.