• 대한안전경영과학회지
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• 제14권4호
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• pp.281-289
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• 2012

Recently, creative innovation has become a major topic in management innovation and due to this, various researches on its need and methodologies are being performed. According to previous studies on ambidexterity, explorative innovation is closer to divergent and right-sided brain, while exploitative innovation is closer to convergent and left-sided brain. Five attributes of the questionnaires were developed based on right-sided and left-sided brain theory. Also, 25 problem solving tools were selected according to previous studies. QC 7 Tools and new QC 7 Tools were frequently used in Six Sigma projects. Other 11 problem solving tools were selected with consideration on its usage frequency. Survey questionnaires were distributed to 25 Six Sigma consultants and 22 were retrieved for this study's use. As a result, 14 tools were identified to hold exploitative attribute while 11 tools were identified to hold explorative attributes.

• 대한수학회보
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• 제39권3호
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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.

• 대한산업공학회지
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• 제24권3호
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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.

• 대한수학회지
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• 제47권3호
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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.

• 대한수의사회지
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• 제14권3호
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• pp.157-160
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• 1978

제 4위좌방변립 발생예에 대하여 그 임상적진단과 수술적정복에 대하여 검토하였다. 박수음을 제외한 제 4위변립증의 특징적진단소견으로 이를 확진할 수 있었고, 좌염부절개에 의하여 제 4 위를 제 1 위우측하부에 결착하는 방법으로 좋은 결과를 얻을 수 있었다.

• 한국수학교육학회지시리즈A:수학교육
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• 제31권2호
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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.

• 대한두경부종양학회지
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• 제33권1호
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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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• 제31권4호
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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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• 제38권3호
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• pp.241-244
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• 2005

57세 남자가 3년 전부터 발생한 좌측 팔의 통증과 감각이상을 주소로 내원하였다. 환자는 경미한 연하곤란을 호소하는 것 이외에 다른 증상은 얼었다. 좌측 팔의 동맥압은 촉지되지 않았으며, 흉부방사선 사진상 우측 대동맥궁이 의심되었다. 대동맥 조영술 상에서 우측 대동맥궁과 Kommerell 게실이 관찰되었고 좌쇄골하 동맥은 기시부의 완전 폐색을 보였으며 혈류는 척추 혈관을 통해 우회하여 쇄골하동맥에 공급되고 있었다. 전신마취 하에 우측 쇄골하 동맥으로부터 8 m 인조혈관을 이용하여 좌쇄골하 동맥에 연결하였다. Kommerell 게실은 크기가 작아 추적 관찰하기로 하였다.

• Asian Pacific Journal of Cancer Prevention
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• 제17권5호
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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.