• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
• /
• v.11B no.3
• /
• pp.86-92
• /
• 2001

This paper is presented for evaluating the performance of slotless Permanent Magnet Linear Synchronous Motors (PMLSM) Which is energized by partially excited primary current. Especially the influence of end-effect due to the moving magnet is investigated in detail. Also partial excitation of primary current for better efficiency and its switching behavior are suggested Capability of PMLSM which is related to speed-force feasibility judging whether motor can meet the desired specifications in the dynamics are investigated. Furthermore control characteristics of PMLSM are considered to verify the validity of dynamic capability in running condition.

• Journal of Radiation Protection and Research
• /
• v.17 no.2
• /
• pp.37-48
• /
• 1992

It was carried out to analyze the nuclear energy deposition rates for the bulk shield components including materials of the primary end shield and side primary systems of Wolsong 2 during steady state operations at 100% full power using ANISN code. This paper has been prepared to support system design of Wolsong 2.

• Bulletin of the Korean Mathematical Society
• /
• v.57 no.5
• /
• pp.1205-1213
• /
• 2020

Let R be a commutative ring with 1 ≠ 0. In this paper, we introduce a subclass of the class of 1-absorbing primary ideals called the class of strongly 1-absorbing primary ideals. A proper ideal I of R is called strongly 1-absorbing primary if whenever nonunit elements a, b, c ∈ R and abc ∈ I, then ab ∈ I or c ∈ ${\sqrt{0}}$. Firstly, we investigate basic properties of strongly 1-absorbing primary ideals. Hence, we use strongly 1-absorbing primary ideals to characterize rings with exactly one prime ideal (the UN-rings) and local rings with exactly one non maximal prime ideal. Many other results are given to disclose the relations between this new concept and others that already exist. Namely, the prime ideals, the primary ideals and the 1-absorbing primary ideals. In the end of this paper, we give an idea about some strongly 1-absorbing primary ideals of the quotient rings, the polynomial rings, and the power series rings.

• Transactions of the Korean Society of Pressure Vessels and Piping
• /
• v.11 no.1
• /
• pp.20-24
• /
• 2015

Steam generator(S/G) tubes in pressurized water reactor (PWR's) are subject to several types of degradation. This degradation includes denting, pitting, intergranular attack(IGA), intergranular stress corrosion cracking(IGSCC), fatigue, fretting and wear. Degradation can be derived from either the primary side(inside) or the secondary side(outside) of the tube. Recent issue for tube degradation in domestic steam generator is the tube end cracking on seal weld region. The seal weld region at the tube end and tube itself is regarded as a pressure boundary between the primary side and the secondary side. One of the Westinghouse Model-F S/G has experienced tube end cracking and its number of plugging approximately becomes to the operating limit up to 5% due to tube end cracking which was reported as SAI/MAI(single/multiple axial indication) or SCI/MCI(Single/multiple circumferential indication) from the results of eddy current testing. Eddy current mock-up test was carried out to determine the origin of cracking whether it is from weld zone area or parent tube. This result was helpful to analyze crack location on ECT data. Correct action on this problem was the installation of tube-end sleeve. Last year, after removing 340 installed plugs from tubes, selected 269 tubes took tube-end sleeve installation. Tube-end sleeve brought pressure boundary from parent tube to installed sleeve tube. Tube-end sleeve has the benefit of reducing outage period and increasing more revenue than replacing S/G. This paper is provided to assist interest parties in effectively understanding this issue.

• Research in Mathematical Education
• /
• v.18 no.4
• /
• pp.257-272
• /
• 2014

This paper examines and presents descriptions of 12 prospective primary teachers' views on the nature of mathematics in USA. All the participants were elementary teacher candidates enrolled in the same mathematics method courses. Interview data show that the prospective primary teachers possess two kinds of views on the nature of mathematics: primarily traditional and even mix of traditional and nontraditional beliefs in terms of Raymond's (1997) belief criteria. Implications for teacher education were discussed at the end of the paper.

• Journal of Chest Surgery
• /
• v.27 no.3
• /
• pp.244-250
• /
• 1994

Early recognition, vigorous preoperative preparation, sophisticated supportive care, control of sepsis, and intensive care nursing have produced remarkably improved results in the management of esophageal atresia. Successful surgery for esophageal atresia and tracheoesophageal fistula was carried out recently. Two neonates with esophageal atresia and distal tracheoesophageal fistula were type C. Transpleural end-to-end repair was carried out after gastrostomy due to low birth weight in case I associated with ventricular septal defect. Case 2 underwent primary retropleural end-to-end repair. A simple one-layer anastomosis with the sutures passing through all layers of`the esophagus was performed in all cases.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.7 no.8
• /
• pp.1770-1785
• /
• 2013

In this paper, a multi-hop transmission protocol based on parallel communication of secondary users (SUs) is proposed. The primary multi-hop network coexists with a set of SUs by cooperative spectrum sharing. The main optimization target of our protocol is the overall performance of the secondary system with the guarantee of the primary outage performance. The energy consumption of the primary system is reduced by the cooperation of SUs. The aim of the primary source is to communicate with the primary destination via a number of primary relays. SUs may serve as extra decode-and-forward relays for the primary network. When an SU acts as a relay for a primary user (PU), some other SUs that satisfy the condition for parallel communication are selected to simultaneously access the primary spectrum for secondary transmissions. For the proposed protocol, two opportunistic routing strategies are proposed, and a search algorithm to select the SUs for parallel communication is described. The throughput of the SUs and the PU is illustrated. Numerical results demonstrate that the average throughput of the SUs is greatly improved, and the end-to-end throughput of the PU is slightly increased in the proposed protocol when there are more than seven SUs.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.56 no.1
• /
• pp.101-107
• /
• 2014

It has been known that Terzaghi's consolidation theory is not well consistent with the consolidation phenomenon on the soft clay ground, but this theory has still been adopted normally in practice because there is no method for estimating the consolidation settlement and rate easier than Terzaghi's theory. It is impossible to map whole part of consolidation settlement vs time curve to the curve of Terzaghi'z average degree of consolidation. If the primary consolidation and the secondary compression are happened same time, it would be useless of trying to find the end of primary consolidation, but it is needed for using Terzaghi's theory that the end of consolidation is determined to the time of beginning consistency between the final settlement analyzed with curve fitting and the experimented consolidation settlement.

• Journal of the Architectural Institute of Korea Structure & Construction
• /
• v.34 no.8
• /
• pp.19-27
• /
• 2018

In this study, annual site and primary energy use intensities (EUIs) and $CO_2$ emission intensities (CEIs) per area by end use were estimated based on the measurement data from June 2016 to May 2017 of 19 sample office buildings in Seoul. In addition, the estimated site EUIs by end use were compared to the U.S. Commercial Buildings Energy Consumption Survey (CBECS) 2012 data. Average site EUIs by end use were found to be in the order of electric appliance (typical floors) > heating > cooling > lighting > air movement > domestic hot water > vertical transportation > city water supply. In the case of primary EUIs and CEIs by end use, electric appliance was found to be the largest. As results of comparison with the CBECS 2012 data, it was found that the site EUIs were similar for heating, cooling, domestic hot water, and electric appliance, etc., but slightly different for lighting and air movement. The number of sample office buildings will continue to increase until 2020 (total number of samples 85) and intensities data by end use will be continuously updated through continuous collection of measurement data.

• Korean Journal of Bronchoesophagology
• /
• v.8 no.1
• /
• pp.61-65
• /
• 2002

Background : Acquired tracheoesophageal fistula(TEF) results mostly from Prolonged tracheal intubation and insertion of nasogastric tube. Although the incidence has decreased since the usage of low pressure, high volume cuff of endotracheal tube, it is seldom cured spontaneously and needs surgical treatment. Material and Methods : We have retrospectively reviewed five cases of TEF who underwent surgical treatment for cure from March, 1990 to September, 2001 and analyzed the cause, treatment, postoperative complications and prognostic factors. Results : Majority were men(80% : 4 of 5 patients) and the mean age was 29.4 years old(range, 11-58). The most predominant etiology was prolonged intubation or tracheostomy(80% : 4 of 5 patients) and 3 of 5 patients were treated by tracheal resection and end to end anastomosis with primary closure of esophagus. Postoperative complications occurred in 4 patients the most common complications were wound infection(4 cases) and esophageal leakage(2 cases). Extubation was done on postoperative day 11.5(range, 1-33) days, and factors causing delayed extubation were status esophagus. epilepticus, edema, and tracheal stenosis. Conclusion : Spontaneous closure of TEF is seldom possible and the surgical treatment of choice is tracheal resection and end to end anastomosis with primary repair of the esophagus. preoperative pulmonary rehabilitation and early extubation postoperatively are important factors for success.