• Journal of the Korean Chemical Society
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• v.29 no.4
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• pp.419-425
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• 1985

N-Methylamidinoglycine, an isomer of creatine which was postulated to be formed enzymatically in vitro, has been synthesized by coupling glycine with N, S-dimethylthiopseudouronium iodide in a yield of approxirnately 60%. On heating in acidic solution, it was converted to a cyclized form (isocreatinine) in analogy with the conversion of creatine to creatinine(anhydrous form). Structures were confirmed by an elemental analysis and proton NMR spectroscopy. Further studies on their characteristics were compared with those of creatine and creatinine in regard to isoelectric points(pI), retardation coefficients(Rf) on thin layer chromatography, and elution profiles on amino acid analyzer. In order to facilitate the comparison, $^{14}C$-labeled creatine, creatinine, isocreatine and isocreatinine were also synthesized.

• Fire Science and Engineering
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• v.22 no.1
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• pp.37-44
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• 2008

The reduced scale fire test provides basic data but it is not enough to analysis real fire problem directly because there is no exact analogy theory between a real fire and the reduced scale model. Therefore, we have developed the 10 MW large scale calorimeter in order to real scale fire test. This advanced large scale calorimeter used for physical properties such as a heat release rate, based upon consumption of $O_2$ method. Using the heptane pool fire, we carried out the calibration in order to evaluation for heat release rate. It is approve that this facility has the reliability and it is capable of applying to the advance fire research in the future.

• Membrane Journal
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• v.12 no.2
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• pp.55-66
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• 2002

fouling phenomena of ion exchange membranes were reviewed for improved design and operation of electodialysis. The membrane fouling index for electrodialysis (EDMFI) was defined for the quantitative analysis of fouling potential as an analogy to the pressure-driven membrane process. fouling phenomena were compared in the electrodialysis experiments with inorganic foulant (silica sol) and organic foulants (humate and bovine serum albumin (BSA)), and their fouling potentials were analyzed using the fouling index. The comparison showed that the EDMFI could be used as a quantitative measure of the fouling tendency in electrodialysis processes. As a novel fouling mitigation method, square wave power was reported to be effective in electrodialysis with organic foulants. The square wave powers having the pulsed electric field enabled to reduce the membrane fouling significantly at an optimal frequency.

• Nuclear Engineering and Technology
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• v.47 no.5
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• pp.567-578
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• 2015

In a nuclear reactor containment, wall condensation forms with noncondensable gases and their accumulation near the condensate film leads to a significant reduction in heat transfer. In the framework of nuclear reactor safety, the film condensation in the presence of noncondensable gases is of high relevance with regards to safety concerns as it is closely associated with peak pressure predictions for containment integrity and the performance of components installed for containment cooling in accident conditions. In the present study, CUPID code, which has been developed by KAERI for the analysis of transient two-phase flows in nuclear reactor components, is improved for simulating film condensation in the presence of noncondensable gases. In order to evaluate the condensate heat transfer accurately in a large system using the two-fluid model, a mass diffusion model, a liquid film model, and a wall film condensation model were implemented into CUPID. For the condensation simulation, a wall function approach with a heat/mass transfer analogy was applied in order to save computational time without considerable refinement for the boundary layer. This paper presents the implemented wall film condensation model, and then introduces the simulation result using the improved CUPID for a conceptual condensation problem in a large system.

• The Journal of the Acoustical Society of Korea
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• v.38 no.3
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• pp.247-255
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• 2019

In this study, to predict the noise of a submarine propeller which is going to become bigger and faster, the non - cavitating propeller noise was predicted based on the numerical analysis which considering the interaction of the hull - appendages - propeller. In order to predict the radiated noise of the propeller, the flow field for the entire region of hull-appendages-propeller was computed by CFD (Computational Fluid Dynamics). And the noise for the thickness noise and the load noise was numerically predicted using FW-H (Ffwocs Williams-Hawkings) acoustic analogy. Numerical noise prediction results were verified by model tests and showed good agreement with the measurement results in predicting total noise level and low frequency noise.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.2
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• pp.39-45
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• 2005

The aim of this research is to predict the thickness and loading noise of the round-tip shaped Hartzell propeller currently used in the general aviation aircraft. Before implementing the noise analysis, the pressure distribution on the propeller was obtained by using the free wake panel method and unsteady Bernoulli's equation. The noise signal at observer position can be obtained by using the FW-H equation. The noise prediction results for the propeller indicates that the thickness noise has s symmetric directivity pattern with respect to the tip path plane, while the noise due to loading shows higher noise directivity toward downstream than the upstream direction from the rotor plane. The loading noise is dominant rather than the thickness noise in normal operating condition.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1996.10a
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• pp.443-449
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• 1996

헬리콥터, 팬, 프로펠러, 터이빈같이 회전익에서 유체역학적 소음이 발생하는 장치의 설계에 있어서는 공기 역학적 성능 분석과 함께 소음에 대한 해석이 절대적으로 필요하다. 근래에 들어와서 소음에 대한 관심이 급격히 증가하고 공항 주변에서의 국제적인 규약들은 낮은 소음 수준(low noise level)을 규정하고 있으며, 이에 따라서 소음을 감소시키려는 연구가 매우 활발히 진행되고 있는 실정이다. 더욱이 컴퓨터의 냉각 팬을 비롯한 공조기기 및 산업기기에 사용되는 회전기계에서 발생되는 소음의 저감은 보다 더 쾌적한 환경을 요구하는 사회적 요구에 부합하면서 공력소음의 연구 분야가 더 넓어지고 있다. 본 논문에서는 소음예측 방법중의 하나인 음향상사(acoustic analogy)를 주파수 영역 방법(frequency domain method)을 이용하여 헬리콥터 블레이드의 고속 충격소음(High Speed Impulsive Noise)을 해석한다. 고속 충격소음은 블레이드-와류 상호작용 소음과 더불어 헬리콥터의 지배적인 소음원으로서 깃끝 속도가 큰 전진 수평비행(forward level flight)또는 제자리 비행(hovering flight)시 발생하는 소음으로 블레이드의 깃끝 마하수(critical Mach number)보다 크거나 비슷할 경우 충격파의 교란에 의해서 일어나는 충격적인 소음을 말한다. 고속 충격소음은 고주파수 스펙트럼 성분과 큰 소음강도를 가지고 있기 때문에 날카로운 금속성의 소리를 내며 먼 거리까지 전파되는 특징을 가지고 있다.

• International Journal of Computer Science & Network Security
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• v.24 no.5
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• pp.165-171
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• 2024

The processes of society's informatization and digitalization necessitate the widespread use of new pedagogical technologies. Through these technologies, comprehensive disclosure of didactic functions of new methods of educational activity and the realization of the potential and creative potential. The use of information and computer multimedia technologies in teaching music art is especially relevant in the intensification of the development of interactive technologies, the transition to mixed forms of learning, and a period of socio-economic and sociopolitical upheavals. The study aims to substantiate the theoretical and applied principles of the analysis of multimedia technology learning musical art in modern conditions and assess the status and trends in their use in conducting educational activities. The study uses general scientific and unique methods of economic analysis, in particular, analysis and synthesis, analogy and comparison, generalization and systematization, and graphic ways. Regarding the results of the study of multimedia technologies for teaching musical art in current conditions, it was found that they contribute to the development of the seeker's creative, creative, and cognitive activity, have a positive impact on learning material, and diversify the educational process. Multimedia technologies such as presentations, programs for watching a video, listening to audio, music and singing karaoke, electronic encyclopedias, and Internet resources are proven to be the most used in music education. They have several qualitative and quantitative advantages, manifested in the possibilities of audio-visual presentation of educational material and significantly higher information density. It is suggested to strengthen the use of such computer programs as Microsoft Word, Ahead Nero, Finale, Adobe Audition, Sound Forge, and Microsoft PowerPoint for musical art classes.

• Archives of design research
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• v.15 no.1
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• pp.27-36
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• 2002

To do this, study of human memory and theoretical approach on form in general is carried out to compare the types of memories and the stage of perceive theoretically to discover the relationship between psychological perceive and form. In the second please, scenario of form recognition in cultural aspect is studied through various written records to obtain unbiased critics on what a person can feel from a form through various analysis and experiment. Examples will be given on products designed on the basis of correlation with form through analysis. Through this procedure, elements of reactions on implicit and explicit is derived (Data obtained from experiments on computers and inquiries are used) Analyzed elements are than divided into, general knowledge, memories of reality and subconsciousness memories and basic mental image and user mental image and mental image of form of each products are analyzed. In the third phase, the way of adapting of the elements obtained from the analysis of implicit and explicit reaction to the field of design is predicted. Together with this, future theme this the study will be suggested. Confusions obtained from this study can be listed as below.

• Journal of Korean Academy of Dental Administration
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• v.11 no.1
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• pp.8-18
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• 2023

The purpose of this study is to examine the organizational culture of dental hospitals and clinics, as well as to assess members' perceptions and actual conditions related to sexual harassment. The research method involved conducting a cross-sectional survey of 149 dental hygienists using random sampling. The analysis utilized frequency analysis and descriptive statistical analysis. Regarding awareness of organizational culture within the workplace, 39.6% responded, "It is difficult to freely use maternity and childcare leave at our workplace". When asked about sexual harassment, 51.7% of respondents said they had received training on sexual harassment prevention. The highest level of sexual harassment experienced was "sexual analogy or evaluation of appearance", at 45.8%. The most common perpetrators of sexual harassment were agency heads and directors, at 37.5%. The most common behavior of the victim at the time was "changing the subject or avoiding the scene" (41.7%). 50.0% of victims of sexual harassment responded to the harm by "just putting up with it". The most common response to the direct and indirect impact of sexual harassment was "there was no specific impact". The most common response from the agency was "there were no suitable measures". Regarding the most necessary policy to prevent sexual harassment, "strict punishment for perpetrators (37.5%)" was the highest. There is a need for organizational and cultural changes to reduce sexual harassment in the workplace. Additionally, it is crucial for the country and society as a whole to actively participate in and improve the system.