• Bulletin of the Korean Mathematical Society
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• v.39 no.3
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• pp.411-422
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• 2002

In this note we are concerned with relationships between one-sided ideals and two-sided ideals, and study the properties of polynomial rings whose maximal one-sided ideals are two-sided, in the viewpoint of the Nullstellensatz on noncommutative rings. Let R be a ring and R[x] be the polynomial ring over R with x the indeterminate. We show that eRe is right quasi-duo for $0{\neq}e^2=e{\in}R$ if R is right quasi-duo; R/J(R) is commutative with J(R) the Jacobson radical of R if R[$\chi$] is right quasi-duo, from which we may characterize polynomial rings whose maximal one-sided ideals are two-sided; if R[x] is right quasi-duo then the Jacobson radical of R[x] is N(R)[x] and so the $K\ddot{o}the's$ conjecture (i.e., the upper nilradical contains every nil left ideal) holds, where N(R) is the set of all nilpotent elements in R. Next we prove that if the polynomial rins R[x], over a reduced ring R with $\mid$X$\mid$ $\geq$ 2, is right quasi-duo, then R is commutative. Several counterexamples are included for the situations that occur naturally in the process of this note.

• Journal of Korean Institute of Industrial Engineers
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• v.24 no.3
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• pp.417-429
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• 1998

This paper considers two-sided (left and right side) assembly lines which are often used, especially in assembling large-sized products such as trucks and buses. A large number of exact algorithms and heuristics have been proposed to balance one-sided lines. However, little attention has been paid to balancing two-sided assembly lines. We present an efficient algorithm based on a branch and bound for balancing two-sided assembly lines. The algorithm involves a procedure for generating an enumeration tree. To efficiently search for the near optimal solutions to the problem, assignment rules are used in the method. New and existing bound strategies and dominance rules are else employed. The proposed algorithm can find a near optimal solution by enumerating feasible solutions partially. Extensive computational experiments are carried out to make the performance comparison between the proposed algorithm and existing ones. The computational results show that our algorithm is promising and robust in solution quality.

• Journal of the Korean Mathematical Society
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• v.47 no.3
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• pp.483-494
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• 2010

Let R be a non-commutative prime ring and I a non-zero left ideal of R. Let U be the left Utumi quotient ring of R and C be the center of U and k, m, n, r fixed positive integers. If there exists a generalized derivation g of R such that $[g(x^m)x^n,\;x^r]_k\;=\;0$ for all x $\in$ I, then there exists a $\in$ U such that g(x) = xa for all x $\in$ R except when $R\;{\cong}\;=M_2$(GF(2)) and I[I, I] = 0.

• Journal of the korean veterinary medical association
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• v.14 no.3
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• pp.157-160
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• 1978

One case of left-sided abomasal displacement is described. The examination methods available to the practitioner do lead to a positive diagnosis except one of the splashing sound of abomasum. Preference is given to laparotomy (rumenotomy) from the left si

• The Mathematical Education
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• v.31 no.2
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• pp.141-144
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• 1992

In this paper, some properties of p-injective ring is studied: The Jacobson radical of a pinjective ring which satisfies the ascending chain condition on essential left ideals is nilpotent. Also, the left singular ideal of a ring which satisfies the ascending chain condition on essential left ideals is nilpotent. Finally, we give an example which shows that a semiprime left p-injective ring such that every essential left ideal is two-sided is not necessarily to be strongly regular.egular.

• Korean Journal of Head & Neck Oncology
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• v.33 no.1
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• pp.57-59
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• 2017

A non-recurrent laryngeal nerve on the left side is a rare anomaly which is reported in 0.04% and it is associated with abnormal developments of the aortic arch during embryogenesis. Although the possibility is extremely low, it is important to consider the possible existence of a non-recurrent laryngeal nerve to prevent a nerve injury during thyroidectomy. We experienced a 42 year-old male with left thyroid papillary cancer who had right side aortic arch and aberrant left subclavian artery. Even though we found that this patient had a recurrent laryngeal nerve, we present this case of the right aortic arch with an aberrant left subclavian artery variation with a brief review of literature.

• Radiation Oncology Journal
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• v.31 no.4
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• pp.239-246
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• 2013

Purpose: We explored whether the deep inspiration breath hold (DIBH) technique using Abches during left-sided breast irradiation was effective for minimizing the amount of radiation to the heart and lung compared to free breathing (FB). Materials and Methods: Between February and July 2012, a total of 25 patients with left-sided breast cancer underwent two computed tomography scans each with the DIBH using Abches and using FB after breast-conserving surgery. The scans were retrospectively replanned using standardized criteria for the purpose of this study. The DIBH plans for each patient were compared with FB plans using dosimetric parameters. Results: All patients were successfully treated with the DIBH technique using Abches. Significant differences were found between the DIBH and FB plans for mean heart dose (2.52 vs. 4.53 Gy), heart V30 (16.48 vs. $45.13cm^3$), V20 (21.35 vs. $54.55cm^3$), mean left anterior descending coronary artery (LAD) dose (16.01 vs. 26.26 Gy, all p < 0.001), and maximal dose to $0.2cm^3$ of the LAD (41.65 vs. 47.27 Gy, p = 0.017). The mean left lung dose (7.53 vs. 8.03 Gy, p = 0.073) and lung V20 (14.63% vs. 15.72%, p = 0.060) of DIBH using Abches were not different significantly compared with FB. Conclusion: We report that the use of a DIBH technique using Abches in breathing adapted radiotherapy for left-sided breast cancer is easily feasible in daily practice and significantly reduces the radiation doses to the heart and LAD, therefore potentially reducing cardiac risk.

• Journal of Chest Surgery
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• v.38 no.3 s.248
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• pp.241-244
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• 2005

A 57-year-old man with numbness and paresthesia of left arm is presented. There was no pulse in the left arm was absent and his chest radiograph suggested right-sided aortic arch. The aortogram showed right-sided aortic arch with Kommerell's diverticulum. The proximal portion of left subclavian artery was totally occluded and blood was being supplied through vertebral arteries to distal subclavian artery. He underwent bypass grafting between both subclavian arteries by an expanded polytetrafluoroethylene graft. Because the size of Kommerell's diverticulum was small, it need to be observed closely.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.5
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• pp.2401-2405
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• 2016

Background: Both colorectal cancer (CRC) and diverticular disease (DD) are common in the affluent West, and their prevalence is also increasing in the rest of the world with economic development. Both diseases have common epidemiologic characteristics; increasing incidence, more common with advancing age and related to specific dietary changes. However, studies of associations between the two have generated mixed results with some showing positive correlations, whilst others have shown no or negative links. Most of these studies have been from the West with study populations that were predominantly Caucasians. Here the focus was on DD and colorectal neoplasms, including CRC, in Brunei. Materials and Methods: All patients who had undergone complete colonoscopy between 2011 and 2014 were identified and retrospectively reviewed. Patients under the age of 18 years old or had previous colonic surgeries (including previous CRC resection) were excluded. Results: The total number of colonoscopies included in the study was 2,766 (mean age $53.2{\pm}14.8$ years old, male 51.8%), of which DD, CRC and colonic polyps were detected in 17.3%, 4.7% and 28.2% respectively. The proportions of DD, polyps and CRC increased proportionally with age (<30 years, 30-49, 50-69 and ${\geq}70$). Overall, there was no association between the presence of DD and CRC (3.6% vs. 5.0%, p=0.179) but there was a significant association between CRC and left sided DD (p=0.034 by trend). There were also a significant association between presence of DD and polyps (36.1% vs. 28.2%, p=0.001), in particular with right-sided and pan-DD (p=0.001 for trend). Conclusions: Our study showed that the prevalence of DD, CRC and polyps increases with age. There were significant associations between presence of left-sided DD with CRC and right-sided or pan-DD with colonic polyps. This suggests shared risk factors. Further studies are required to assess links in other countries of the Asian Pacific region.

• Radiation Oncology Journal
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• v.38 no.1
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• pp.68-76
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• 2020

Purpose: The present study was conducted to compare dosimetric parameters for the heart and left lung between free breathing (FB) and deep inspiration breath hold (DIBH) and determine the most important potential factors associated with increasing the lung dose for left-sided breast radiotherapy using image analysis with 3D Slicer software. Materials and Methods: Computed tomography-simulation scans in FB and DIBH were obtained from 17 patients with left-sided breast cancer. After contouring, three-dimensional conformal plans were generated for them. The prescribed dose was 50 Gy to the clinical target volume. In addition to the dosimetric parameters, the irradiated volumes and both displacement magnitudes and vectors for the heart and left lung were assessed using 3D Slicer software. Results: The average of the heart mean dose (D_mean) decreased from 5.97 to 3.83 Gy and V₂₅ from 7.60% to 3.29% using DIBH (p < 0.001). Furthermore, the average of D_mean for the left lung was changed from 8.67 to 8.95 Gy (p = 0.389) and V₂₀ from 14.84% to 15.44% (p = 0.387). Both of the absolute and relative irradiated heart volumes decreased from 42.12 to 15.82 mL and 8.16% to 3.17%, respectively (p < 0.001); however, these parameters for the left lung increased from 124.32 to 223.27 mL (p < 0.001) and 13.33% to 13.99% (p = 0.350). In addition, the average of heart and left lung displacement magnitudes were calculated at 7.32 and 20.91 mm, respectively. Conclusion: The DIBH is an effective technique in the reduction of the heart dose for tangentially treated left sided-breast cancer patients, without a detrimental effect on the left lung.