• Asian-Australasian Journal of Animal Sciences
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• v.22 no.5
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• pp.611-617
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• 2009

This study was aimed at a genetic evaluation of Iranian Holstein cattle for milk and fat yields and calculating daughter yield deviation (DYD) of bulls. The data file that was used in this research included 367,943 first three lactation records of 186,064 Holstein cows which calved between 1983 and 2006 in 11,806 herd-year-season groups. The model included herd-year-season of calving and age at calving as fixed effects and animal and permanent environment as random effects. Mean breeding values of cows for each year were regressed on birth year to estimate genetic trends. Genetic trends in milk and fat yields were greater for cows born after 1997 (59.38 kg/yr and 1.11 kg/yr for milk yield and fat yield, respectively). Animal evaluations were partitioned into contribution from parent average, yield deviation (YD) and progeny. DYD of bulls was calculated as described by VanRaden and Wiggans (1991). DYD provides an indication of the performance of the daughters of a bull without consideration of his parents or sons. Variance of bull DYD was greater than variance of their predicted transmitting ability (PTA). Correlation of bull DYD and PTA was dependent on the number of daughters and when this increased, the correlation of DYD and PTA was increased. Also as lactation number of daughters increased, the correlation of bull DYD and PTA was increased.

• International Journal of Highway Engineering
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• v.13 no.3
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• pp.7-14
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• 2011

The numerical analyses were performed to investigate the curling behavior of the post-tensioned prestressed concrete approach slab (PTAS) under environmental loads. A technique to include properly the boundary conditions of one end of PTAS that was connected to the bridge abutment using hinges was proposed for the numerical model. The applicability of a simplified model not having hunches was also investigated. By using the developed models, the curling behavior of PTAS was analyzed when the foundation settlement occurred. The analysis results showed that the maximum tensile stress obtained from the simplified model involving a simplified hinge connection was very closed to that obtained from a rigorous model. When the slab curled up, the maximum tensile stress occurred in the model including no foundation settlement, but when the slab curled down, the maximum stress occurred in the model including partial settlement of the foundation. Therefore, the design of PTAS should be performed considering those maximum tensile stresses.

• Journal of Microbiology and Biotechnology
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• v.25 no.7
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• pp.1093-1100
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• 2015

Acetate and lactate in growth media are detrimental to the production of Thermus maltogenic amylase (ThMA), a heterologous protein, as well as to the growth of recombinant Escherichia coli. Only 50 mM of acetate or 10 mM of lactate reduced 90% of specific ThMA activity. In this study, mutant E. coli strains blocked in the ackA-pta or ackA-pta and ldh pathways were created, characterized, and assessed for their culture performace in 300 L-scale fermentation. The ackApta and ldh double-mutant strain formed significantly less lactate and acetate, and produced a concomitant increase in the excretion of pyruvate (17.8 mM) under anaerobic conditions. The ackA-pta mutant strain accumulated significant acetate but had an approximately 2-fold increase in the formation of lactate. The ackA-pta and ldh double-mutant strain had superior overall performance in large-scale culture under suboptimal conditions, giving 67% higher cell density and 66% higher ThMA activity compared with those of the control strain. The doublemutant strain also achieved a 179% improvement in volumetric ThMA production.

• Journal of Welding and Joining
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• v.12 no.4
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• pp.85-101
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• 1994

Effect of Cr, Cu and Ni metal powders addition on the alloyed layer of aluminum alloy (AC2B) has been investigated with the plasma transferred arc (PTA) overlaying process. The overlaying conditions were 125-200A in plasma arc current, 150mm/min in process speed and 5-20g/min in powder feeding rate. Main results obtained are summarized as follows: 1) It was made clear that formation of thick surface alloyed layer on aluminum alloy is possible by PTA overlaying process. 2) The range of optimum alloying conditions were much wider in case of Cu and Ni powder additions than the case of Cr powder addition judging from the surface appearance and the bead macrostructure. 3) Alloyed layer with Cu showed almost the homogeneous microstructure through the whole layer by eutectic reaction. alloyed layers with Cr and Ni showed needle-like and agglomerated microstructures, the structure of which has compound layer in upper zone of bead by peritectic and eutectic-peritectic reactions, respectively. 4) Microconstituents of the alloyed layer were analyzed as A1+CrA $l_{7}$ eutectics, C $r_{2}$al sub 11/, CrA $l_{4}$, C $r_{4}$A $l_{9}$ and C $r_{5}$A $l_{*}$ 8/ for Cr addition, Al+CuA $l_{2}$(.theta.) eutectics and .theta. for Cu addition, and Al+NiA $l_{3}$ eutectics. NiA $l_{3}$, N $i_{2}$A $l_{3}$ and NiAl for Ni addition. 5) Concerning defect of the alloyed layer, many blow holes were seen in Cr and Ni additions although there was lesser in Cu addition. Residual gas contents in blow hole for Cu and Ni alloyed layer were confirmed as mainly $H_{2}$ and a littie of $N_{2}$ Cracking was observed in compound zone of the alloyed layer in case of Cr and Ni addition but not in Cu alloyed layer.r.r.

• Journal of the Korean Society for Heat Treatment
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• v.13 no.4
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• pp.246-252
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• 2000

Stellite 12 alloy-powder was overlaid on 410 stainless steel valve seat using plasma transferred arc(PTA) process. Variation of characteristic of microstructure and hardness of deposit with current(90~150 A) and preheat temperature(R.T.~$400^{\circ}C$) was investigated. Important conclusion obtained are as follows; All welding conditions used produced a sound deposit layer with no defect in single pass welding. The maximum deposit had 4.0~4.8 mm in thickness and its bead width was increased with increase of current and preheat temperature. The deposit showed hypoeutectic microstruture, which was consisting of primary cobalt dendrite and networked $M_7C_3$ type eutectic carbides. The amount of eutectic carbides was decreased and its dendritic secondary arm spacing was increased with increase of current. Hardness of the deposit was decreased with increase of current. Preheat temperature up to $400^{\circ}C$, however, showed little influence on the hardness and microstructure. The hardness was also influenced by diluted Fe content near the interface in addition to microstructure and dendritic secondary arm spacing. Hot hardness at $500^{\circ}C$ showed higher than 300 HV.

• Journal of the Korea Society of Computer and Information
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• v.19 no.6
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• pp.71-80
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• 2014

Employing PTAS to building minimum spanning tree for a large number of equal distribution input terminal nodes can be a effective way in execution time. But applying PTAS to building minimum spanning tree for tremendous unequal distribution node may lead to performance degradation. In this paper, a partial PTAS reflecting the scheme into specific node dense area is presented. In the environment where 90% of 50,000 input terminal nodes stand close together in specific area, approximate minimum spanning tree by our proposed scheme can show about 88.49% execution time less and 0.86%tree length less than by existing PTAS, and about 87.57%execution time less and 1.18% tree length more than by Prim's naive scheme. Therefore our scheme can go well to many useful applications where a multitude of nodes gathered around specific area should be connected efficiently as soon as possible.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.1
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• pp.19-28
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• 2020

The spacer, which is located between the bucket and the arm of an excavator, has a role in preventing damage to the excavator arm during excavation work. When the durability of the spacer is increased, the lifetime of the arm can be extended and the processing costs can be reduced. To increase the durability of the spacer, tungsten carbide (WC) coating was applied on the surface of a spacer using the plasma transferred arc (PTA) process. The confirm the durability, a wear test using a pin-on disk type of wear testing machine was done under the given conditions and the wear amount on the surface of a tested specimen was measured using reflective digital holography. The results were compared with that of ALPHA-STEP.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.10
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• pp.837-843
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• 2012

Compared to conventional pure-tone audiometer(PTA), the computerized one has several advantages such as relatively lower price, better flexibility, and easy operation. In addition, the computerized PTA can be easily extended to support automatic calibration. In this study, the support of automatic calibration in the computerized PTA has been addressed using the Linux realtime spectrum analyzer and network. In terms of accuracy, the new automatic calibration machine was compared to the existing manually operated one. According to the comparison, normal operation and high accuracy were observed within the scope of the international standard.

• Journal of the Korean Society of Radiology
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• v.85 no.4
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• pp.746-753
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• 2024

Purpose This study aims to evaluate the incidence and management of venous ruptures after percutaneous transluminal angioplasty (PTA) for dysfunctional arteriovenous (AV) access. Materials and Methods From January 1998 to December 2015, 13506 PTA, mechanical thrombectomy, and thrombolysis procedures were performed in 6732 patients. The venous rupture rate following PTA was obtained, and access circuit primary patency (ACPP) was compared according to the etiology (PTA, thrombotic occlusion, and treatment type) of the venous rupture present. Results Venous rupture developed in 604 of the 13506 procedures. Venous ruptures were more frequent in female, AV graft cases, and in cases accompanied by thrombosis. Balloon tamponade was performed in 604 rupture cases, and stents were deployed in 119 cases where contrast extravasation and flow stasis persisted. ACPP was significantly better in the non-ruptured AV access circuits than in the ruptured group. However, AV access type and thrombosis was not associated with primary patency. In ruptured cases, ACPP is 8.4 months for prolonged balloon tamponade and 11.2 months for bare-metal stent insertion, showing statistically significant difference. Conclusion Balloon tamponade and bare-metal stent placement are effective treatment for PTA-induced venous ruptures. In particular, stent placement showed a similar ACPP to that of non-ruptured AV access circuits.

• Proceedings of the KWS Conference
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• 1994.10a
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• pp.177-179
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• 1994