• Title/Summary/Keyword: back analysis method

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Design Analysis of Hydraulic Excavator since 1990 (1990년대 유압굴삭기 조형 분석에 관한 연구)

  • 윤진필;문무경
    • Archives of design research
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    • v.13 no.4
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    • pp.233-242
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    • 2000
  • The traditional image of hydraulic excavator started to change in two ways since 1990. First, post-heavy equipment's visual image was new waves to traditional image of heavy, strong, and wild. They are the negative aspect that excavators have. Another movement of getting rid of its negative image can be found in late-heavy equipment, which was intended to adapt traditional and positive, but off negative images. In 1990s, the design trend is moving from warm/hard to warm/soft, and KOBELCO can be exceptional example that went even further, gone up to cool-soft image. KOBELCO specially aimed 'post- excavator image' strategy, which has been successful. Image of cabin as a human space changed little bit further than outside image. Each company tried to differentiate the design of cabin focusing on its safety. Following paragraphs show specific trend of image change in form, colour, texture, and the composition. Major visual image change in form tries to follow the image of cars and home appliances which are showing the movement from tough and hard image to soft one. Structural change on local image shows the movement from angular edge to edgeless and the movement of cabin's pillar C placed to back of the equipment with gentle inclination. All of these movements are the result of effort to improve traditional excavator's negative image, that top structure is assembled separately, to positive ones. Today's tendency about its color becomes important to apply two different colour styles. Each style has brightness and tone comparison. As an enormous power convey system, it was in common that its brightness comparison was useful because of the alarm of its damage possibility. However, as its colour control and its design have been emphasized gradually, the tone comparison takes a part in an important role, too. As an example, there is an occasion that these comparisons are compromised simultaneously. In the respect of its image creation, its texture treatments make the tendency of being the same as passenger cars. It is caused from its development of the manufacture techniques of from the fabrication method in small business to the press method in big firm. Further, it is also because of its improvement of painting & coating skills. It may prohibit the reflection effect from solar rays. In the point of view of its visual images, it is recognized the prominent tendency that its composition has been gradually decreased. Lots of windows and the frames tends dark-colour as a whole. It is more preferred to have one colour image, but except KOBELCO and HITACHI. As well, there is another high-tendency to improve its standard treatments, especially for its corner and texture treatments.

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The Analysis and Design of Advanced Neurofuzzy Polynomial Networks (고급 뉴로퍼지 다항식 네트워크의 해석과 설계)

  • Park, Byeong-Jun;O, Seong-Gwon
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.39 no.3
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    • pp.18-31
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    • 2002
  • In this study, we introduce a concept of advanced neurofuzzy polynomial networks(ANFPN), a hybrid modeling architecture combining neurofuzzy networks(NFN) and polynomial neural networks(PNN). These networks are highly nonlinear rule-based models. The development of the ANFPN dwells on the technologies of Computational Intelligence(Cl), namely fuzzy sets, neural networks and genetic algorithms. NFN contributes to the formation of the premise part of the rule-based structure of the ANFPN. The consequence part of the ANFPN is designed using PNN. At the premise part of the ANFPN, NFN uses both the simplified fuzzy inference and error back-propagation learning rule. The parameters of the membership functions, learning rates and momentum coefficients are adjusted with the use of genetic optimization. As the consequence structure of ANFPN, PNN is a flexible network architecture whose structure(topology) is developed through learning. In particular, the number of layers and nodes of the PNN are not fixed in advance but is generated in a dynamic way. In this study, we introduce two kinds of ANFPN architectures, namely the basic and the modified one. Here the basic and the modified architecture depend on the number of input variables and the order of polynomial in each layer of PNN structure. Owing to the specific features of two combined architectures, it is possible to consider the nonlinear characteristics of process system and to obtain the better output performance with superb predictive ability. The availability and feasibility of the ANFPN are discussed and illustrated with the aid of two representative numerical examples. The results show that the proposed ANFPN can produce the model with higher accuracy and predictive ability than any other method presented previously.

A Study on the Reasonable Application Method of Steel Fiber Reinforced Shotcrete in NATM Tunnel (NATM 터널에서 합리적인 강섬유보강 숏크리트 적용방안에 관한 연구)

  • Seok, Chongken;Ahn, Taebong
    • Journal of the Korean GEO-environmental Society
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    • v.15 no.9
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    • pp.19-28
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    • 2014
  • Recently, the proportion of long tunnel has increased for efficient use of land due to limited land area, driving convenience and high speed. RMR and Q-System of empirical methods has been mainly used for tunnel support design in domestic. Although shotcrete is the key to NATM tunnel, the related studies are insufficient. So, steel fiber reinforced shotcrete is applied to II~V grade rocks on domestic and foreign applications. And same amount of shotcrete is equally applied to tunnel roof and wall regardless of the applied rock load. Shotcrete is applied excessively rather than the original proposed value of RMR and Q-System. Thus, this study is to reevaluate the application part of plain shotcrete and steel fiber reinforced shotcrete of tunnel in Daebo granite, and to propose the reasonable application method of steel fiber reinforced shotcrete. Field test and numerical back analysis using measurements were performed to verify stability. According to results, if RMR values are the upper class in the III grade, it can be designed in accordance with upper grade. In addition, if rock condition is good as a mountain tunnel in Daebo granite, it can be applied for plain shotcrete to III grade rocks because there is also no stability problems. And although steel fiber reinforced shotcrete is applied only crown of the tunnel in IV grade rocks, it is possible to secure stability for falling rock by key-block.

Mapping, Tissue Distribution and Polymorphism of Porcine Retinol Binding Protein Genes (RBP5 and RBP7)

  • Gong, W.H.;Tang, Z.L.;Han, J.L.;Yang, S.L.;Wang, H.;Li, Y.;Li, K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.21 no.11
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    • pp.1544-1550
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    • 2008
  • The retinoids (vitamin A and its derivatives) play a critical role in vision, growth, reproduction, cell differentiation and embryonic development. Using the IMpRH panel, porcine cellular retinol binding protein genes 5 and 7 (RBP5 and RBP7) were assigned to porcine chromosomes 5 and 6, respectively. The complete coding sequences (CDS) of the RBP5 and RBP7 genes were amplified using the reverse transcriptase polymerase chain reaction (RT-PCR) method, and the deduced amino acid sequences of both genes were compared to human corresponding proteins. The mRNA distributions of the two genes in adult Wuzhishan pig tissues (lung, skeletal muscle, spleen, heart, stomach, large intestine, lymph node, small intestine, liver, brain, kidney and fat) were examined. A total of nine single nucleotide polymorphisms (SNPs) were identified in two genes. Three of these SNPs were analyzed using the polymerase chain reaction-restriction-fragment length polymorphism (PCR-RFLP) method in Laiwu, Wuzhishan, Guizhou, Bama, Tongcheng, Yorkshire and Landrace pig breeds. Association analysis of genotypes of these SNP loci with economic traits was done in our experimental populations. Significant associations of different genotypes of $RBP5-A/G^{63}$, $RBP5-A/G^{517}$ and $RPB5-T/C^{intron1-90}$ loci with traits including maximum carcass length (LM), minimum carcass length (LN), marbling score (MS), back fat thickness at shoulder (SBF), meat color score (MCS) and hematocrit (HCT) were detected. These SNPs may be useful as genetic markers in genetic improvement for porcine production.

Assist works as to implant system which dental hygienists perform in a clinical field (Implant system에 있어서 치과위생사의 assist work)

  • Nam, Yong-Ok;Kim, Sun-Sook;Kim, Min-Ja;Ju, On-Ju
    • Journal of Korean society of Dental Hygiene
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    • v.9 no.2
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    • pp.147-163
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    • 2009
  • This study was attempted in order to look into 'Assist work' as to Implant system which dental hygienists perform in a clinical field. Subjects of this research were 362 dental hygienists who work at general hospital, University hospital, dental hospital, and dental clinics located in Seoul, Kyeong-gi, In-chon, and Jeon-buk area. As to research tool, we produced questionnaire which was comprised of the total 25 items regarding 3 of general features (age, career of dental hygienist, and personality), 6 of implant system assist work, 3 of Informed consent before surgery, 6 of preoperative preparation and maintenance related business, and 7 items related to postoperative maintenance. By using SPSS program, collected data was analyzed. Results of analysis in this study were as follow; 1. As to implant related education, dental hygienists' experience of education was high as 77.7%, and the people who is needed more education was 86.3%. Consequently, dental hygienists' concern about the implant related education was very high. 2. It was observed that most of informed consent making approvement by announcement to the surgical operation was made by dental hygienist before implant as 95%. 3. Over 80% of dental hygienists performed acquisition of cleanliness technology, motivation, back up articles preparation, treatment area arrangement, and etc. which we can check by preoperative maintenance items. In particular, response about the motivation was very high as more than 90%. 4. When performing an operation, in the case of disinfecting finger was low for 53.9% and the method was mainly washing with drug solution, and gown sterilization was performed only in 52.2%. Therefore education regarding disinfection was urgently needed. 5. Significance of education could be known that answers of hygienists experienced education appeared highly in items of maintenance method and there was statistically significant difference(p<0.05). 6. In case that assist work were 21cases or greater, agitation measurement was the most many performed in 68.9% and difference was showed up significantly(p<0.001). 7. Evaluation about periodontal tissue was high in dental hygienists who had experienced education and also there was statistically significant difference. In conclusion, assist work of dental hygienists was very comprehensive when implant surgery was performed, and all of items excluding hand disinfection or gown disinfection were highly showed up in most of hygienists. However, since there is the limit that we didn't investigate the quality of performing contents. It is considered that further study regarding the content has to be progressed for supporting this result in the future.

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Chemical Analysis and Thermoelectric Properties of the PbSnTe Semiconductors (화학조성에 따른 PbSnTe계 반도체의 열전특성조사)

  • Oh, Kyu-Whan;Oh, Seung-Mo
    • Applied Chemistry for Engineering
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    • v.1 no.1
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    • pp.83-90
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    • 1990
  • The semiconducting $(Pb_1\;_xSn_x)_1$ $_yTe_y$, one of the low - temperature thermoelectric materials, has been prepared and its chemical composition and nonstoichiometry has been analyzed. The content of Pb in the specimens was determined by the complexometric back - titration method with EDTA and Pb(II) standard solutions. Te - content was analyzed with the redox titration method. The electrical conductivity and the thermoelectric power have also been measured by the DC 4 - probe and the heat-pulse technique, respectively. All of the specimens showed a nonstoichiometric behavior in their chemical compositions (Te excess), thus gave rise to a p - type semiconducting property, and the nonstoichoimetry became bigger as the Sn - content increased. The thermoelectric power vs. temperature results have been analyzed upon the basis of the Fermi level vs. temperature profiles in the saturation regime. The specimen of x=0.1 evolved a transition from p - to n - type property at about 670K, which has been explained by the fact that the mobility of electrons is bigger than that of holes in the temperature range of the intrinsic regime.

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In-Vitro Thrombosis Detection of Mechanical Valve using Artificial Neural Network (인공신경망을 이용한 기계식 판막의 생체외 모의 혈전현상 검출)

  • 이혁수;이상훈
    • Journal of Biomedical Engineering Research
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    • v.18 no.4
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    • pp.429-438
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    • 1997
  • Mechanical valve is one of the most widely used implantable artificial organs of which the reliability is so important that its failure means the death of patient. Therefore early noninvasive detection is essentially required, though mechanical valve failure with thrombosis is the most common. The objective of this paper is to detect the thrombosis formation by spectral analysis and neural network. Using microphone and amplifier, we measured the sound from the mechanical valve which is attached to the pneumatic ventricular assist device. The sound was sampled by A/D converter(DaqBook 100) and the periodogram is the main algorithm for obtaining spectrum. We made the thrombosis models using pellethane and silicon and they are thrombosis model on the valvular disk, around the sewing ring and fibrous tissue growth across the orifice of valve. The performance of the measurment system was tested firstly using 1 KHz sinusoidal wave. The measurement system detected well 1KHz spectrum as expected. The spectrum of normal and 5 kinds of thrombotic valve were obtained and primary and secondary peak appeared in each spectrum waveform. We find that the secondary peak changes according to the thrombosis model. So to distinguish the secondary peak of normal and thrombotic valve quantatively, 3 layer back propagation neural network, which contains 7, 000 input node, 20 hidden layer and 1 output was employed The trained neural network can distinguish normal and valve with more than 90% probability. As a conclusion, the noninvasive monitoring of implanted mechanical valve is possible by analysing the acoustical spectrum using neural network algorithm and this method will be applied to the performance evaluation of other implantable artificial organs.

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THE EFFECT OF SOME CANAL PREPARATION TECHNIQUES ON THE SHAPE OF ROOT CANALS (수종의 근관형성 방법이 근관 형태에 미치는 영향)

  • Lee, Ji-Hyeon;Cho, Yong-Bum
    • Restorative Dentistry and Endodontics
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    • v.24 no.2
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    • pp.337-345
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    • 1999
  • The purpose of this study was to compare the shape of root canal after instrumentation with some engine driven NiTi files. Thirty narrow and curved canals(15-35 degree) of mesial canals of extracted human mandibular first molars were divided into three groups. Group 1: After radicular access with Gates Glidden drill, apical shaping using step back method with Flexo file Group 2: After radicular access with Gates Glidden drill, apical shaping with Profile .04 Group 3: Canal shaping with GT file and Profile .04. Using modified Bramante technique, the root was sectioned at 2 mm from apical foramen, height of curvature, 2 mm from canal orifice. Canal centering ratio, amount of transport, amount of dentin removed, shape of canal were measured and statistical analysis is done using SPSS Program V 7.5. The results were as follows: 1. Canal centering ratio of group 3 was the lowest at coronal part, but there was no statistical difference. Centering ratio of group 2 was the lowest at curve part, and there was statistical difference between group 1(P<0.05). Centering ratio of group 2 was the lowest at apical part, but there was no statistic difference. 2. Amount of transport of group 3 was the lowest at coronal part, but there was no statistical difference. Amount of transport of group 2 was the lowest at curve part, and there was statistical difference between group 1(P<0.05). Amount of transport of group 3 was the lowest at apical part, and there was statistical difference between group 1 and group 2, group 1 and group 3(P<0.05). 3. Amount of dentin removed of group 3 was the lowest at coronal part, bur there was no statistical difference. Amount of dentin removed of group 2 was the lowest at curve part, but there was no statistical difference. Amount of dentin removed or group 2 was the lowest at apical part, and there was statistical difference between group 1 and group 2, group 1 and group 3(P<0.05). 4. The shape of the canals after instrumentation varied among the groups. The majority of canals at coronal and curve part for group 1 were round in shape(7 in 10), those at apical part were oval(8 in 10). The majority of canals at coronal part for group 2 were round in shape(7 in 10) and there was no difference in the number of shape at other part. There was no difference in the number of shape at every part for group 3. As above results, NiTi rotary instrumentation showed a trend to remain more centered in the canal than SS file instrumentation. At using NiTi file, coronal shaping with Gates Glidden drill was not statistically different from shaping with GT file. But shaping with GT file showed tapered canals, so it may be said that shaping with GT file is a safe and valuable instrumentation method.

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Motion Monitoring using Mask R-CNN for Articulation Disease Management (관절질환 관리를 위한 Mask R-CNN을 이용한 모션 모니터링)

  • Park, Sung-Soo;Baek, Ji-Won;Jo, Sun-Moon;Chung, Kyungyong
    • Journal of the Korea Convergence Society
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    • v.10 no.3
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    • pp.1-6
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    • 2019
  • In modern society, lifestyle and individuality are important, and personalized lifestyle and patterns are emerging. The number of people with articulation diseases is increasing due to wrong living habits. In addition, as the number of households increases, there is a case where emergency care is not received at the appropriate time. We need information that can be managed by ourselves through accurate analysis according to the individual's condition for health and disease management, and care appropriate to the emergency situation. It is effectively used for classification and prediction of data using CNN in deep learning. CNN differs in accuracy and processing time according to the data features. Therefore, it is necessary to improve processing speed and accuracy for real-time healthcare. In this paper, we propose motion monitoring using Mask R-CNN for articulation disease management. The proposed method uses Mask R-CNN which is superior in accuracy and processing time than CNN. After the user's motion is learned in the neural network, if the user's motion is different from the learned data, the control method can be fed back to the user, the emergency situation can be informed to the guardian, and appropriate methods can be taken according to the situation.

Improvement in flow and noise performance of backward centrifugal fan by redesigning airfoil geometry (익형 형상 재설계를 통한 후향익 원심팬의 유동 및 소음성능 개선)

  • Jung, Minseung;Choi, Jinho;Ryu, Seo-Yoon;Cheong, Cheolung;Kim, Tae-hoon;Koo, Junhyo
    • The Journal of the Acoustical Society of Korea
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    • v.40 no.6
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    • pp.555-565
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    • 2021
  • The goal of this study is to improve flow and noise performances of existing backward-curved blade centrifugal fan system used for circulating cold air in a refrigerator freezer by optimally designing airfoil shape. The unique characteristics of the system is to drive cold airflow with two volute tongues in combination with duct system in a back side of a refrigerator without scroll housing generally used in a typical centrifugal fan system. First, flow and noise performances of existing fan system were evaluated experimentally. A P-Q curve was obtained using a fan performance tester in the flow experiment, and noise spectrum was measured in an anechoic chamber in the noise experiment. Then, flow characteristics were numerically analyzed by solving the three-dimensional unsteady Navier-Stokes equations and noise analysis was performed by solving the Ffowcs Williams and Hawkins equation with input from the flow simulation results. The validity of numerical results was confirmed by comparing them with the measured ones. Based on the verified numerical method, blade inlet and outlet angles were optimized for maximum flow rate using the two-factor central composite design of the response surface method. Finally, the flow and noise performances of a prototype manufactured with the optimum design were experimentally evaluated, which showed the improvement in flow and noise performance.