• Steel and Composite Structures
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• 제21권1호
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• pp.217-247
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• 2016

Five extended cylindrical reticulated shells are proposed by changing distribution rule of diagonal rods based on three fundamental types. Modeling programs for fundamental types and extended types of cylindrical reticulated shell are compiled by using the ANSYS Parametric Design Language (APDL). On this basis, conditional formulas are derived when the grid shape of cylindrical reticulated shells is equilateral triangle. Internal force analysis of cylindrical reticulated shells is carried out. The variation and distribution regularities of maximum displacement and stress are studied. A shape optimization program is proposed by adopting the sequence two-stage algorithm (RDQA) in FORTRAN environment based on the characteristics of cylindrical reticulated shells and the ideas of discrete variable optimization design. Shape optimization is achieved by considering the objective function of the minimum total steel consumption, global and locality constraints. The shape optimization for three fundamental types and five extended types is calculated with the span of 30 m~80 m and rise-span ratio of 1/7~1/3. The variations of the total steel consumption along with the span and rise-span ratio are analyzed with contrast to the results of shape optimization. The optimal combination of main design parameters for five extended cylindrical reticulated shells is investigated. The total steel consumption affected by distribution rule of diagonal rods is discussed. The results show that: (1) Parametric modeling method is simple, efficient and practical, which can quickly generate different types of cylindrical reticulated shells. (2) The mechanical properties of five extended cylindrical reticulated shells are better than their fundamental types. (3) The total steel consumption of cylindrical reticulated shells is optimized to be the least when rise-span ratio is 1/6. (4) The extended type of three-way grid cylindrical reticulated shell should be preferentially adopted in practical engineering. (5) The grid shape of reticulated shells should be designed to equilateral triangle as much as possible because of its reasonable stress and the lowest total steel consumption.

• 한국통신학회논문지
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• 제28권10A호
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• pp.816-829
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• 2003

본 논문에서는 동일 상관 신호군을 이용하는 M-ary UWB (Ultra Wide Band) 다원 접속 시스템에서 PN(Pseudo Noise) 부호 기반의 시간 도약 시퀀스를 이용하는 경우의 성능을 평가하였다. 특히 심벌 수 M이 증가해도 신호 펄스열의 길이가 변화하지 않아 M에 관계없이 동일 심벌 전송률을 갖게 되는 M-ary UWB 시스템 (시스템 #1)과 신호 펄스열의 길이가 M의 증가에 따라 확장되어 M이 증가하여도 동일 비트 전송률을 갖게 되는 M-ary UWB 시스템 (시스템 #2)을 모두 고려하여, UWB 실내 무선 다중 경로 채널 하에서의 심벌오율 성능을 이상적인 랜덤 시간 도약 시퀀스를 적용한 다원 접속 시스템의 성능과 비교 분석하였다. 모의 실험 결과, PN 부호 기반의 시간 도약 시퀀스가 이상적인 랜덤 시퀀스와 거의 유사한 매우 우수한 성능을 나타냄을 알 수 있었다. 또한, 심벌수가 증가함에 따라 시스템 #2의 경우가 시스템 #1의 경우보다 다원 접속 간섭에 대한 강인성 측면에 있어서 월등히 우수함을 확인하였다.

• Journal of Microbiology and Biotechnology
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• 제26권9호
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• pp.1643-1649
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• 2016

The aims of this study were to characterize the molecular epidemiological profiles of CTX-M-producing uropathogenic Escherichia coli isolates from a tertiary hospital in Daejeon, Korea, and to investigate the genetic diversity and compare the prevalence of sequence types (STs) in different areas. Extended spectrum β-lactamase-producing E. coli strains isolated from urine were analyzed for CTX-M, integrons, and insertion sequence common regions (ISCRs) by PCR and sequencing. Multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), phylogenetic analysis, and rep-PCR were also used for molecular typing of the isolates. Of 80 CTX-M producers, 31 and 46 expressed CTX-M-15 and CTX-M-14, respectively. MLST analysis indicated that the most prevalent ST was ST131 (n = 34, 42.5%), followed by ST38 (n = 22, 27.5%), ST405 (n = 8, 10.0%), and ST69 (n = 6, 7.5%). Most CTX-M producers harbored class 1 integrons. ST131 strains belonged to phylogenetic group B2 and showed identical rep-PCR patterns, whereas ST69, ST38, and ST405 strains belonged to phylogenetic group D; the ST38 and ST405 strains displayed the same rep-PCR pattern, respectively. ST131 and ST38 isolates showed 21 and 19 distinct types, respectively, by PFGE. In Daejeon, D-ST38 CTX-M-14 producers were relatively more prevalent than in other countries and Korean cities. Our results indicate that CTX-M-producing E. coli isolates belonged mostly to ST131 or ST38 and were more related to hospital-onset than to community-onset infections and that the bla_CTX-M gene may vary according to the ST.

• 품질경영학회지
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• 제17권1호
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• pp.69-81
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• 1989

This study is concerned with a job sequencing method using the concept of sampling technique in the case of Job Shop. This is the follow study of Kang and Ro (1988) which examined the possibility of application of sampling technique to determine the Job Sequence in the case of Flow Shop. Not only it is very difficult, but also it takes too much time to develop the appropriate job schedules that satisfy the complex work conditions. The most job sequencing algorithms have been developed to determine the best or good solution under the special conditions or assumptions. The application areas of these algorithms are also very narrow, so it is very hard to find the appropriate algorithm which satisfy the complex work conditions. In this case it is very desirable to develop a simple job sequencing method which can select the optimal job sequence or near optimal job sequence with a little effort. This study is to examine the effect of sampling job sequencing which can select the good job of 0.01%~5% upper good group. The result shows that there is the sets of 0.05%~23% job sequence group which has the same amount of performance measure with the optimal job sequence in the case of experiment of N/M/G/$F_{max}$. This indicates that the sampling job sequencing method is a useful job sequencing method to find the optimal or good job sequence with consuming a small amount of time. The results of ANOVA show that the only one factor, number of machines is the significant factor for determining the job sequence at ${\alpha}=0.01$. It takes about 10 minutes to compare the number of 10,000 samples of job sequence by personal computer and it is proved that the selection rate of the same job sequence with optimal job sequence is 23.0%, 3.9% and 0.065% in the case of 2 machines, 3 machines and 4 machines, respectively. The area of application can readily be extended to the other work condition.

• Journal of the Korean Statistical Society
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• 제34권4호
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• pp.263-272
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• 2005

Let {$X_n,\;n{\ge}1$} be a sequence of negatively associated random variables which are dominated randomly by another random variable. We discuss the limit properties of weighted sums ${\Sigma}^n_{i=1}a_{ni}X_i$ under some appropriate conditions, where {$a_{ni},\;1{\le}\;i\;{\le}\;n,\;n\;{\ge}\;1$} is an array of constants. As corollary, the results of Bai and Cheng (2000) and Sung (2001) are extended from the i.i.d. case to not necessarily identically distributed negatively associated setting. The corresponding results of Chow and Lai (1973) also are extended.

• Journal of Microbiology and Biotechnology
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• 제24권3호
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• pp.421-426
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• 2014

To characterize the extended-spectrum beta-lactamases (ESBLs) in diarrheagenic Escherichia coli from Korea in 2008-2011, we screened seven enterotoxigenic E. coli (ETEC) and one enteroaggregative E. coli (EAEC) that produce ESBLs from a nationwide survey. All eight isolates produced CTX-M-type ESBLs, including CTX-M-12 (n = 4), CTX-M-14 (n = 2), and CTX-M-15 (n = 2). PCR-based replicon typing indicated that the $bla_{CTX-M-12}$ genes of four ETEC isolates were carried on a conjugative IncF plasmid, whereas the $bla_{CTX-M-14}$ of one EAEC was located on an IncK plasmid. This is the first report of the occurrence of $bla_{CTX-M}$ genes in clinical isolates of EAEC in Korea. The ESBL-producing isolates were shown to be different based on pulsed-field gel electrophoresis and multilocus sequence typing, whereas the four isolates with CTX-M-12 were clonally related. These observations raise an alarm for the spread of plasmid-mediated resistance to ESBL among diarrheagenic E. coli.

• 한국CDE학회논문집
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• 제17권3호
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• pp.216-223
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• 2012

Bill of material (BOM), which structurally represents the relation among parts constructing a product, is usually created when enterprises start to develop a new product. And it is shown as various types of BOM according to business needs and usage such as eBOM (engineering BOM), gBOM (green BOM), mBOM (manufacturing BOM), pBOM (process BOM), etc. eBOM, generally called BOM and created in the design stage of the new product, includes the drawing information of parts in the view of product function. eBOM is extended to gBOM adding the material information of parts to cope with international regulations for environment. eBOM is transformed to mBOM, which includes manufacturing sequence of parts and adds some parts required to fabricate parts and to assemble the product. mBOM is also extended to pBOM adding the process information of each part and additional assembly processes. This study introduces the concept of multi-BOM covering eBOM, gBOM, mBOM and pBOM, and proposes an advanced way to manage product data using multi-BOM system. The multi-BOM system proposed is to manage their relations using transformation function of BOM and master information of all BOMs.

• 천문학회보
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• 제43권1호
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• pp.60.1-60.1
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• 2018

We investigate the $SFR-M_{\star}$ relation of the infrared luminous galaxies selected in either $11{\mu}m$ and $15{\mu}m$ from the $5.6deg^2$ of the AKARI NEP-Wide field. From the constructed multi-wavelength catalog spanning $0.3{\mu}m$ to $24{\mu}m$, we select 3,408 S11 > $50{\mu}Jy$ galaxies and 1,896 L15 > $20{\mu}Jy$ galaxies which corresponds to $L_{IR}{\sim}10^{11}L_{\odot}$ at z ~ 0.5 and 0.7 respectively. Photometric redshifts of the selected galaxies were derived using LePHARE and Coleman Extended templates. ~98% S11 selected galaxies are galaxies with (median redshift) ~ 0.4, and ~96% L15 selected galaxies are galaxies with ~ 0.6. Star formation rates and stellar mass of these galaxies were calculated using MAGPHYS which derives physical parameters with SED fitting. In the SFR-$M_{\star}$ diagram, $11{\mu}m/15{\mu}m$ selected galaxies are located in the main sequence of star-forming galaxies at z ~ 1.

• Infection and chemotherapy
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• 제50권4호
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• pp.357-361
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• 2018

While carbapenems are the drug of choice to treat extended-spectrum-${\beta}$-lactamase (ESBL)-producing strains, some alternative carbapenem-sparing regimens are suggested for antibiotic stewardship. We experienced a case of ciprofloxacin treatment failure for acute pyelonephritis caused by an apparently susceptible Escherichia coli. A 71-year-old woman presented the emergency department with fever for 7 days and bilateral flank pain for 2 days. The laboratory results and abdominopelvic computed tomography finding were compatible with acute pyelonephritis. During 3-day ciprofloxacin therapy, the patient remained febrile with persistent bacteremia. After the change in antibiotics to ertapenem, the patient's clinical course started to improve. ESBL-producing E. coli isolates were identified in all three consecutive blood samples. Pulsed-field gel electrophoresis (PFGE) patterns, serotypes, and sequence types showed the three isolates were derived from the identical strain. The isolates produced CTX-M-14 type ESBL belonging to the ST69 clonal group. Despite in vitro susceptibility, the failure was attributed to a gyrA point mutation encoding Ser83Leu within quinolone resistance-determining regions. This case suggests that ciprofloxacin should be used cautiously in the treatment of serious infections caused by ciprofloxacin-susceptible, ESBL-producing E. coli, even in acute pyelonephritis because in-vitro susceptibility tests could fail to detect certain genetic mutations.

• 대한임상검사과학회지
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• 제48권3호
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• pp.210-216
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• 2016

최근 들어 CTX-M형 extended-spectrum ${\beta}$-lactamase(ESBL) 생성 대장균이 국내는 물론 전세계적으로 빠르게 증가하고 있다. 본 연구에서는 충청지역에 위치한 일개의 대학병원에서 분리된 대장균을 대상으로 ESBL 유전자를 중합효소연쇄반응 및 염기서열 분석방법을 통해 확인하였으며, 같은 방법으로 ESBL 생성 대장균으로부터 plasmid mediated quinolone resistance (PMQR) 유전자의 빈도를 조사하였다. 16.0%에 해당하는 25균주가 CTX-M-14를 생성하였으며 이중 9균주는 CTX-M-15도 동시에 생성하는 것으로 나타났다. 항균제 감수성 시험결과 CTX-M형 ESBL을 생성하는 대장균은 모두 cefotaxime에 내성을 보였다. 한편 CTX-M형 ESBL을 생성하는 대장균의 48% (12균주)가 PMQR 유전자를 포함하고 있음이 확인되었는데 8균주가 qnrS1유전자를 그리고 8균주가 aac(6')-Ib-cr 유전자를 포함하고 있었다. 그 중 4균주는 두 개의 유전자를 모두 가지고 있는 것으로 나타났다. 본 연구에서는 플라스미드를 통해 확산될 수 있는 ESBL 및 PMQR 유전자가 대장균 사이에 확산되어 있음을 확인하였다. 항균제 내성유전자들의 확산을 막기 위해서는 지속적인 내성유전자의 모니터링과 감시가 필요할 것으로 사료된다.