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        검색결과 79

        1.
        2024.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        배경/목적: 본 연구에서는 췌장 낭종을 가진 환자들 중 임상적 으로 분지형 췌관내유두상점액종양(branch-duct intraductal papillary mucinous neoplasm)으로 여겨지는 환자에서 췌장암 및 우려되는 특징의 누적 발생률을 조사하였다. 방법: 분지형 췌관내유두상점액종양으로 추적관찰한 환자 177명의 자료를 후향적으로 분석하였다. 영상 검사를 통해 주췌관과의 소통이 확인된 췌장 낭종을 ‘분지형 췌관내유두상 점액종양 의심’으로 정의하였고, 주췌관과의 명확한 소통이 없는 경우를 ‘분지형 췌관내유두상점액종양 추정’으로 정의 하였다. 결과: 환자 중 30.5%가 분지형 췌관내유두상점액종양 의심으로 분류되었다. 진단 시의 중위 연령은 64세였으며, 낭종 크기의 중앙값은 13 mm였다. 진단 시 19명(10.7%)의 환자가 우려되는 특징을 보였으며, 고위험 인자(high risk stigmata)를 보인 환자는 없었다. 70.5개월의 추적 기간 동안 3명의 환자에게서 췌장암이 발생하였으며 96개월 시점의 누적 발생률은 4.0% (95% 신뢰 구간[confidence interval, CI], 0.98-10.76%)였다. 진단 시 우려되는 특징이 없는 158명의 환자에서 우려되는 특징의 누적 발생률은 24개월 시점에 5.1% (95% CI, 2.37-9.28%)였고, 96개월 시점에 11.2% (95% CI, 6.34-17.53%)였다. 우려되는 특징의 발생은 분지형 췌관내 유두상점액종양 추정 군(p=0.102)과 75세 미만 환자(p=0.463) 에서 더 낮았으나, 이러한 차이는 통계적으로 유의하지 않았다. 특히, 75세 이상 환자 군에서는 2년이 지난 이후 우려되는 특징은 발생하지 않았다. 결론: 저위험 췌장 낭종 환자에서 췌장암 및 우려되는 특징의 누적 발생률은 현저히 낮았다. 또한, 첫 2년 동안 변화가 없는 고령 환자의 경우 감시를 중단하는 것을 고려할 수 있다.
        4,000원
        2.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We examine a single machine scheduling problem with step-improving jobs in which job processing times decrease step-wisely over time according to their starting times. The objective is to minimize total completion time which is defined as the sum of completion times of jobs. The total completion time is frequently considered as an objective because it is highly related to the total time spent by jobs in the system as well as work-in-progress. Many applications of this problem can be observed in the real world such as data gathering networks, system upgrades or technological shock, and production lines operated with part-time workers in each shift. Our goal is to develop a scheduling algorithm that can provide an optimal solution. For this, we present an efficient branch and bound algorithm with an assignment-based node design and tight lower bounds that can prune branch and bound nodes at early stages and accordingly reduce the computation time. In numerical experiments well designed to consider various scenarios, it is shown that the proposed algorithm outperforms the existing method and can solve practical problems within reasonable computation time.
        4,000원
        3.
        2024.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Restraints of Branch Lines are used as earthquake-resistant support devices for fire-fighting pipes along with sway brace devices. The central types are aligned and fixed in a straight line with center of the pipe, but the eccentric types are fixed to on side of the pipe, so a bending moment occurs. In this study, three specimens each of central type and eccentric type were installed at an angle of 45° from the vertical and a monotonic compression load of 1340N was applied. All central type samples satisfied 17.8mm of the allowable displacement, but all eccentric type samples failed to meet the target load and buckled. Therefore, when considering the performance of eccentric type restraints, both compressive load and bending moment must be considered. Even through material mechanics calculations, the yield stress of eccentric type - 3/8 inch all threaded steel bolt - exceeds 320Mpa of the allowable stress. A experiment standards need to be established for eccentric type restraints.
        4,000원
        5.
        2021.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study evaluated the biological activity and cytoprotective effect of guava (Psidium guajava L.) branch against oxidative stress. The contents of vitamin C, beta-carotene, total carotenoids, quercetin and catechin determined were 26.783, 43.676, 65.083, 58.245, and 8.309 mg/100 g, respectively. To measure antioxidant activity, the guava branch was extracted using various concentrations of ethanol (60, 80, or 100%) and water. The highest content of polyphenols (0.245 mg gallic acid equivalent/mg residue) and flavonoids (0.128 mg cathechin equivalent/mg residue) was found in the 100% ethanol extract of the branch (E100). Moreover, E100 also possessed the highest radical scavenging activities and showed the highest inhibition rate of α-glucosidase (77.692%). E100 was the most effective extract to impart cytoprotectant activity against oxidative stress in HepG2 cells. Taken together, our results determine the promising antioxidant activity of guava branch, and indicate the potential to be applied as a natural antioxidant.
        4,000원
        6.
        2018.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        At present, an important research area is the search for materials that are compatible with CMOS technology and achieve a satisfactory response rate and modulation efficiency. A strong local field of graphene surface plasmon polariton (SPP) can increase the interaction between light and graphene, reduce device size, and facilitate the integration of materials with CMOS. In this study, we design a new modulator of SPP-based cycle branch graphene waveguide. The structure comprises a primary waveguide of graphene–LiNbO3–graphene, and a secondary cycle branch waveguide is etched on the surface of LiNbO3. Part of the incident light in the primary waveguide enters the secondary waveguide, thus leading to a phase difference with the primary waveguide as reflected at the end of the branch and interaction coupling to enhance output light intensity. Through feature analysis, we discover that the area of the secondary waveguide shows significant localized fields and SPPs. Moreover, the cycle branch graphene waveguide can realize gain compensation, reduce transmission loss, and increase transmission distance. Numerical simulations show that the minimum effective mode field area is about 0.0130l2, the gain coefficient is about 700 cm–1, and the quality factor can reach 150. The structure can realize the mode field limits of deep subwavelength and achieve a good comprehensive performance.
        4,000원
        7.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Improving efficiency of the telecommunication is crucial to the development and growth of Korean economy. Recently, it has become important with the huge development of information technology and its greater potential for extensive impact on the rest of the economy. Hence, it is useful to determine the factors that help enhance efficiency in telecommunication and consider them in improving the evaluation model. This study applies DEA (data envelopment analysis) to evaluate the relative efficiency of 51 branches of a Korean telecommunication company. Using the super-efficiency approach, we tested outliers which may affect the results and ranked the efficient branches. A method of deriving key variables applied to business operation is proposed to identify the key performance indicators for evaluation that takes environmental (non-discretionary) factors into account. We used the extended CCR model proposed by Banker and Morey to investigate the influence of non-discretionary factor. The information provided by the model (slacks, weights) and the sensitivity analysis shows that the most important indicator that affects the branch performance is operating cost. The results of sensitivity analysis show that average efficient score decreases from 0.972 (base case) to 0.863 for CASE2-COST. The average score of the data proves the priority of operating cost over other indicators. The effect of environmental (non-discretionary) variable was found to be significant. The population effect was positive and improved overall efficiency by 0.91% on average. Non-discretionary factor plays a meaningful role explaining the performance of branches. The performance optimization report can help a manager of an inefficient branch to develop branch strategies. Managers can identify the top-performing units, study best practices and adopt the strategy to the organization.
        4,000원
        8.
        2017.04 구독 인증기관 무료, 개인회원 유료
        This study is investigated the process of calculating the support service cost for the oversea plants which are rapidly increasing from domestic automobile companies and removing the corresponding value from the cost of the domestic production products. In order to calculate the service cost for oversea support cost, survey methods was used among various options and The rate of contribution to individual work was obtained through revision works. We conclude that about 25% of the indirect processing costs of domestic production products should be eliminated and replaced with the cost of overseas support services.
        4,000원
        11.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        신품종 Phalaenopsis ‘SM 5616’은 2003년 경북대에서 Doritaenopsis ‘Sogo Vivien’과 Phal. ‘Zuma’s Pixie’를 모본과 부본으로 교배하여 육성한 개체 중에서 선발한 적색 소형 다 화 분지성이다. 2004년부터 2005년까지 2년에 걸쳐 실생 300 개체를 양성하여 이들 중에서 영양생장과 개화특성이 우수한 개체 ‘03-05-61’을 선발하였다. 2006년과 2007년에 1차, 2차 특 성검정을 통하여 품종의 안정성과 균일성을 확인하고 ‘SM 5616’으로 명명하였다. ‘SM 5616’은 화색이 화사하고 선명한 적색(71A)이며, 화형은 안아피기로 안정되어 있다. 꽃의 길이 와 폭은 각각 4.3cm, 4.6cm로 소형이다. 복총상화서로 볼륨 이 있으며 소형 캐주얼분화에 적합하다. 잎의 길이와 폭은 각 각 13.2cm, 7.2cm이며 엽형은 난형으로 수평이다. 기내증식 율이 높고 변이가 거의 없으며 영양생장 우수하여 재배관리가 용이하다. Phal. ‘SM 5616’은 2011년 12월 21일 국립종자원에 품종등록(등록번호 제3824호)하여 종자산업법에 의해 보호받 고 있으며 현재 상미원에서 관리하고 있다.
        4,000원
        13.
        2015.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Branch duct intraductal papillary mucinous neoplasms of the pancreas (BD-IPMN) without malignant features rarely developed into invasive cancer. However, invasive cancer is aggressive once an invasive change occurs. We report three cases of invasive cancers which developed in patients with BD-IPMN and they showed grave clinical courses. All patients were diagnosed with BD-IPMN < 3 cm without malignant features on imaging. Invasive cancer was detected at 2.5 years, 3.0 years, and 4.0 years after BD-IPMN detection in each patient. The intervals of invasive cancer and the last follow-up were 9 months, 3 years, and 1.5 years in the three patients, respectively. All patients were diagnosed with locally advanced pancreas invasive cancers and were treated with palliative chemotherapy or conservative management. The patients died at 3 months, 9 months, and 10 months after the diagnosis of invasive cancers, respectively. We report three cases of invasive cancer developed in BD-IPMN patients and followed fatal courses.
        4,000원
        14.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We focus on the fire scheduling problem (FSP), the problem of determining the sequence of targets to be fired at, for the objective of minimizing makespan to achieve tactical goals. In this paper, we assume that there are m available weapons to fire at n targets (> m) and the weapons are already allocated to targets. One weapon or multiple weapons can fire at one target and these fire operations should start simultaneously while the finish time of them may be different. We develop several dominance properties and a lower bound for the problem, and suggest a branch and bound algorithm implementing them. Also, In addition, heuristic algorithms that can be used for obtaining an initial upper bound in the B&B algorithm and for obtaining good solutions in a short time were developed. Computational experiments are performed on randomly generated test problems and results show that the suggested algorithm solves problems of a medium size in a reasonable amount of computation time. The proposed lower bound, the dominance properties, and the heuristics for upper bound are tested in B&B respectively, and the result showed that lower bound is effective to fathoming nodes and the dominance properties and heuristics also worked well. Also, it is showed that the CPU time required by this algorithm increases rapidly as the problem size increases. Therefore, the suggested B&B algorithm would be limited to solve large size problems. However, the employed heuristic algorithms can be effectively used in the B&B algorithm and can give good solutions for large problems within a few seconds.
        4,000원
        16.
        2015.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Branch duct intraductal papillary mucinous neoplasms (BD-IPMNs) are characterized by cystic dilation of secondary ducts clearly communicating with a normalsized main pancreatic duct and seem to have a less aggressive clinical course than those arising from the main duct. BD-IPMNs are related to pancreatitis but the causal relationship is unclear. We report a case of a 62-year-old woman initially thought to have pseudocysts complicated by idiopathic recurrent pancreatitis but was finally diagnosed with BD-IPMN leading to recurrent acute pancreatitis attacks. The patient had six episodes of acute pancreatitis over 5 years. An abdominal computed tomography scan revealed two cystic lesions of 2.0 and 1.5 cm in the pancreatic body, which appeared at the second episode of acute pancreatitis. Each pancreatitis episode improved with conservative treatment, but the cystic lesions increased in size to 2.5 and 3.5 cm during the late follow-up period. A distal pancreatectomy was performed under the diagnosis of recurrent pancreatitis caused by BD-IPMN. The pathological findings revealed BD-IPMN with moderate dysplasia. We herein present a case of BDIPMN mimicking pancreatic pseudocysts with a review of the literature.
        4,000원
        17.
        2015.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이 연구는 중국 내몽고 쿠부치사막지역의 사막화확산 방지를 위한 사막복구조림을 실시함으로써 장기적으로 사막화지역에 적합한 사방기술을 향상시키는데 기여하고자 수행하였다. 연구지역은 모래가 약 97%로 식재시 지속적인 수분공급이 필요하고, 토양pH가 7.2~7.9인 약알칼리성토양으로 토양양료가 대단히 부족한 상태로 나타났다. 우리나라 산림청이 조림한 지역에서 양수(楊樹, Populus simonii Carr.)의 평균활착률은 87.8%로 나타난 반면, 사류(沙柳, Salix gordejevaii Chang et. Skv.) 평균활착률은 76.8%로, 양수보다 저조하였다. 양수의 평균 신초생장량은 50.4 cm로 나타났고, 사류의 평균 신초생장량은 67.8 cm로 나타나 신초생장량은 사류가 양수보다 높은 것으로 나타났다. 경기도가 조림한 지역에서 양수의 평균활착률은 89.5%로 나타난 반면, 사류의 평균활착률은 68.3%로 양수보다 현저히 낮아, 보식이 필요한 것으로 나타났다. 양수의 평균 신초생장량은 56.7 cm로 나타났고, 사류의 평균 신초생장량은 56.9 cm로 나타나 두 수종 간 차이는 없는 것으로 나타났다.
        4,200원
        18.
        2014.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        소형 다화 분지성의 품종을 육성하기 위하여 호접란 ‘KSVivien’은 2004년 강산난원에서 Dtps. ‘Sogo Vivien’과‘Brother Little Hatter’을 각각을 모부본으로 교배하여 육성한 F1개체 중에서 선발한 소형 다화 분지성의 신품종이다. 2005~2006년에 걸쳐 실생개체 중에서 영양생장과 개화특성이 우수한 개체 KS-507-9를 선발하였다. 2007년과 2009년에 각각 1차, 2차 특성검정을 통하여 품종의 안정성과 균일성을 확인하고 ‘KS Vivien’으로 명명하였다.‘KS Vivien’은 화색이 연분홍(2N81B)에 줄무니가 있는스트라이프계통이며, 화형은 앉아피기로 꽃의 길이와 폭은 각각 4.0, 4.3cm로 소형이다. 화서의 형태는 분지하는복총상화서이다. 잎의 길이와 폭은 각각 9.9, 6.4cm이며엽형은 좁은 도난형의 반직립이다. 기내증식율이 높고 식물체가 강건하고 생육이 빠르기 때문에 재배가 용이한 품종이다. 2010년 11월 11일 품종등록(등록번호 제3377호)하여 종자산업법에 의해 보호받고 있다.
        4,000원
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