• Title/Summary/Keyword: Internal Hole

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Effects of No Stiffness Inside Unbonded Tendon Ducts on the Behavior of Prestressed Concrete Containment Vessels

  • Noh, Sang-Hoon;Kwak, Hyo-Gyong;Jung, Raeyoung
    • Nuclear Engineering and Technology
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    • v.48 no.3
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    • pp.805-819
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    • 2016
  • The numerical simulation methodologies to evaluate the structural behaviors of prestressed concrete containment vessels (PCCVs) have been substantially developed in recent decades. However, there remain several issues to be investigated more closely to narrow the gap between test results and numerical simulations. As one of those issues, the effects of no stiffness inside unbonded tendon ducts on the behavior of PCCVs are investigated in this study. Duct holes for prestressing cables' passing are provided inside the containment wall and dome in one to three directions for general PCCVs. The specific stress distribution along the periphery of the prestressing duct hole and the loss of stiffness inside the hole, especially in an unbonded tendon system, are usually neglected in the analysis of PCCVs with the assumption that the duct hole is filled with concrete. However, duct holes are not small enough to be neglected. In this study, the effects of no stiffness inside the unbonded tendon system on the behaviors of PCCVs are evaluated using both analytical and numerical approaches. From the results, the effects of no stiffness in unbonded tendons need to be considered in numerical simulations for PCCVs, especially under internal pressure loading.

Improvement of Hybrid EL Efficiency in Nanoparticle EL Devices by Insertion of the Layers of PVK and BaF2

  • Lee, Jun-Woo;Cho, Kyoung-Ah;Kim, Hyun-Suk;Park, Byoung-Jun;Kim, Sang-Sig;Kim, Sung-Hyun
    • Transactions on Electrical and Electronic Materials
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    • v.6 no.3
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    • pp.101-105
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    • 2005
  • Electroluminescence(EL) and current-voltage(I-V) characteristics of hybrid EL devices containing Pr and Mn co-doped ZnS nanoparticles were investigated in this study. For the insertion of a hole transport layer of poly (N-vinyl carbazole)(PVK), the current level became lower due to the accumulation of electrons at the interface between PVK and nanoparticles. When both PVK and buffer layer $BaF_2$ were simultaneously introduced, the enhanced EL efficiency and improved I-V characteristics were obtained. This results from the additional increase of hole injection owing to the internal field induced by the significant accumulation of electrons at the interface. The presence of buffer layer $BaF_2$ together with PVK makes it possible the charge accumulation enough to induce the sufficient internal field for further hole injection.

Adjacent Matrix-based Hole Coverage Discovery Technique for Sensor Networks

  • Wu, Mary
    • Journal of the Korea Society of Computer and Information
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    • v.24 no.4
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    • pp.169-176
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    • 2019
  • Wireless sensor networks are used to monitor and control areas in a variety of military and civilian areas such as battlefield surveillance, intrusion detection, disaster recovery, biological detection, and environmental monitoring. Since the sensor nodes are randomly placed in the area of interest, separation of the sensor network area may occur due to environmental obstacles or a sensor may not exist in some areas. Also, in the situation where the sensor node is placed in a non-relocatable place, some node may exhaust energy or physical hole of the sensor node may cause coverage hole. Coverage holes can affect the performance of the entire sensor network, such as reducing data reliability, changing network topologies, disconnecting data links, and degrading transmission load. It is possible to solve the problem that occurs in the coverage hole by finding a coverage hole in the sensor network and further arranging a new sensor node in the detected coverage hole. The existing coverage hole detection technique is based on the location of the sensor node, but it is inefficient to mount the GPS on the sensor node having limited resources, and performing other location information processing causes a lot of message transmission overhead. In this paper, we propose an Adjacent Matrix-based Hole Coverage Discovery(AMHCD) scheme based on connectivity of neighboring nodes. The method searches for whether the connectivity of the neighboring nodes constitutes a closed shape based on the adjacent matrix, and determines whether the node is an internal node or a boundary node. Therefore, the message overhead for the location information strokes does not occur and can be applied irrespective of the position information error.

Development of Waterproof Electric Outlet using Silicon Packing Technology (실리콘 패킹 기술을 이용한 방수 콘센트의 개발)

  • Choi, Chung-Seog;Kim, Chang-Soung
    • Proceedings of the KIEE Conference
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    • 2008.04b
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    • pp.85-87
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    • 2008
  • In this paper, we manufactured waterproof outlet that use silicon packing know-how. Developed outlet is waterproof packing on pins of the plug insertion hole and electric wire insertion hole. Therefore, outlet body internal furnace water can prevent that is flowed in. Temperature anomaly can use in back large outer wall, restaurant exposed easily to moisture, bathroom, laundry, a laboratory and science room, auditorium, etc. That is estimate that contribute on courtesy call of electricity calamity.

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A study on the Change of Diameter Based on Cutting Conditions in AL6061-T4 Boring Machining (AL6061-T4의 보링가공 시 절삭조건에 따른 직경 변화에 관한 연구)

  • Chun, Se-Ho
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.19 no.6
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    • pp.49-54
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    • 2020
  • The purpose of this study is to investigate the effects of the change in the spindle speed and the feed rate on the diameter change of a hole using a boring cutter for the internal boring process of AL6061-T4 alloys. The experimental results are quantitatively analyzed by applying the factor analysis and the response surface analysis of the experimental design method. The tendency of the diameter change according to the change in the spindle speed and feed level is also evaluated. During the internal boring process of AL6061-T4 alloys, the main factor affecting the diameter change is the spindle speed in which the diameter decreases as the number of revolutions increases. In addition, the diameter tends to increase as the feed is increased; however, as the number of spindle revolutions increases, the influence of the feed decreases.

Application of Taguchi Method for the Selection of Chip Breaker (칩브레이크 선정을 위한 Taguchi 방법의 적용)

  • 전준용
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.7 no.3
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    • pp.118-125
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    • 1998
  • Chip control is a major problem in automatic machining process, especially in finish turning operation. In this case, chip breaker is one of the important factors to be determined. As unbroken chips are grown. these deteriorate the surface roughness. and proces automation can not be carried out. In this study to get rid of chip curling problem while turning internal hole. optimal chip breaker is selected from the experiment. The experiment is planned with Taguchi's method that is based on the orthogonal arrary of design factors. From the response table. cutting speed, feedrate, depth of cut and tool geometry turn to be major factors affecting chip formation. Then, optimal chip breaker is selected. and this is verified as good enough for chip control from the experiment.

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The bibliographical study on the senile dementia (노인성치매(老人性痴呆)에 대(對)한 문헌적(文獻的) 고찰(考察))

  • Kim, Hyun-Ah;Jeong, Ji-Cheon;Lee, Won-Chel
    • The Journal of Internal Korean Medicine
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    • v.13 no.2
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    • pp.57-69
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    • 1992
  • The study has been carried out to investigate of the senile dementia by referring to 35 literratures. The results were as follows ; 1. In oriental medical science, senile dementia is belong to the category of dullness(매病), insanity(癲狂證), weak(虛勞), amnesia(健忘), etc. 2. The cause of senile dementia summarize the phlegm preventid-heart hole(痰迷心竅), marrow lack(髓海不足), aged follow weaking of body and disfunction of the internal organs(年老體弱과 臟腑機能 失調), the bad blood with vatal block(氣滯血瘀), feeling inharmony, etc in the view of oriental medical science and make the vanishment of the cerebral atrophy and the cerebral cell but havn't indicated the remarkable cause in that of western medical science. The diseases with cause make a point of Alzheimer's dementia, frequent infarction dementia, etc and psychological and environmental factor too. The marrow lack is related to Alzheimer's dementia, the feeling inharmony, psychologic and environmental factor, the phlegm prevented-heart hole and bad blood with vatal block, frequent infarction dementia. 3. The senile dementia is related cleary to the function of the internal organs in oriental medical sciences respect Especially in relation to kidney and marrow, it is presented new cause view to solve the cure problem of western medical science is studying its cause only the anatomic pathology with cerebrum and is thinking to solve cure possibility. 4. The symptom of senile dementia is as follows. The obstacle of a aspect of the Language, Emotion, Behavior. mute, speech inversion, sometimes a laugh sometimes a cry, behavior strange, failure of memory etc. 5. The treatment of senile dementia is follows. The methodes of cure apply phlegm changed-mud(豁痰化濁), self-kidney and added marrow(補腎益髓), self-energy and nutritive blood(益氣補血), vital blood(祛瘀活血), peace of mind and relief(安神情志). The medicines of cure make the most of (sesimtang, jwagui-hwan, tonggwuhwalhuel tang) add and subtract, daeboweonjeon, guibitang, and so on.

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Non-surgical Recovery of a Chronic Subdural Hemorrhage Patient via the Exclusive Administration of Oryeong-san: A Case Report (오령산 단독 투여에 의한 만성 경막하출혈 환자의 비수술적 회복)

  • Juhwan Song;Sangho Ji;Sunny Kang;Sangkwan Lee;Cheol-Hyun Kim
    • The Journal of Internal Korean Medicine
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    • v.44 no.5
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    • pp.867-874
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    • 2023
  • Introduction: Chronic subdural hemorrhage (CSDH) primarily affects the elderly, and its incidence is rising due to aging trends. Although burr-hole craniostomy is a common treatment for CSDH, it often has a high recurrence rate and can sometimes result in poor outcomes. Oryeong-san, a traditional Korean medicine, is emerging as a potential remedy, with documented cases in both Korea and Japan. Case Presentation: In March 2021, a patient was diagnosed with an intracerebral hemorrhage in the left basal ganglia. A subsequent brain computed tomography in June 2022 revealed CSDH. Given the potential need for surgery if no CSDH absorption occurred, the patient was treated with Oryeong-san. Later computed tomography scans indicated that surgery was no longer necessary. Conclusions: This study evaluated the efficacy of Oryeong-san in treating CSDH. The results demonstrated complete CSDH absorption with no observed side effects, highlighting Oryeong-san as a promising and safe therapeutic option.

NUMERICAL STUDY ON FILM-COOLING EFFECTIVENESS FOR VARIOUS FILM-COOLING HOLE SCHEMES (다양한 막냉각 홀 형상에 대한 막냉각 효율의 수치해석)

  • Kim, S.M.;Lee, K.D.;Kim, K.Y.
    • Journal of computational fluids engineering
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    • v.16 no.4
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    • pp.92-99
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    • 2011
  • In order to protect the turbine blade from working fluid of high temperature, many cooling techniques such as internal convection cooling, film cooling, impinging jet cooling and thermal barrier coating have been developed. With all other things, film-cooling has been widely used as the important alternative. In the present work, numerical analysis has been performed to investigate and to compare the film-cooling performance of various film-cooling hole schemes such as cylindrical, crescent, louver, and dumbbell holes. To analyze the turbulent flow and the film-cooling mechanism, three-dimensional Reynolds-averaged Navier-Stokes analysis has been performed with shear stress transport turbulence model. The validation of numerical results has been assessed in comparison with experimental data. The characteristics of fluid flow and the film-cooling performance for each shaped hole have been investigated and evaluated in terms of centerline, laterally averaged and spatially averaged film-cooling effectivenesses. Among the film cooling holes, the dumbbell shaped hole shows better film-cooling effectiveness than the other shaped holes. And the louver and cylindrical shaped hole show the worst film cooling performance, and concentrated flows on near the centerline only.

Theoretical Studies on Dicyanoanthracenes as Organic Semiconductor Materials: Reorganization Energy

  • Park, Young-Hee;Kim, Yun-Hi;Kwon, Soon-Ki;Koo, In-Sun;Yang, Ki-Yull
    • Bulletin of the Korean Chemical Society
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    • v.31 no.6
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    • pp.1649-1656
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    • 2010
  • Internal reorganization energy due to the structural relaxation in hole or electron hopping mechanism is one of the measurements of key indices in designing an organic thin film transistor (OTFT) for flexible display devices. In this study, the reorganization energies of dicyanoanthracenes for the hole and electron transfer were estimated by adiabatic potential energy surface and normal mode analysis method in order to examine the effect on the energies for the positional variation of the cyano substituents in the anthracene as a protocol of acenes to design an organic field effect transistor. The reorganization energy for the hole transfer was reduced considerably upon cyanation of anthracene, especially at the 9,10-positions of anthracene, and the origin of the reduction was interpreted in terms of understanding the coupling of vibrational modes to the hole transfer.