• 제목/요약/키워드: Dead end

검색결과 230건 처리시간 0.026초

중간 사건이 결측되었거나 구간 중도절단된 준 경쟁 위험 자료에 대한 회귀모형 (Regression models for interval-censored semi-competing risks data with missing intermediate transition status)

  • 김진흠;김자연
    • 응용통계연구
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    • 제29권7호
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    • pp.1311-1327
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    • 2016
  • 본 논문에서는 종말 사건에 대한 정보는 주어져 있지만 중간 사건이 구간 중도절단되었거나 연구 기간 도중에 추적이 끊겨 중간 사건의 발생 유무를 모르는 준 경쟁 위험 자료에 다중상태모형을 적용하여 모수를 추정하는 방법을 제안하였다. 이를 위해 상태 간 전이 강도는 정규 프레일티를 랜덤효과로 가진 Cox 비례위험모형을 따른다고 가정하였다. 다섯 가지 상태를 가진 다중상태모형에서 가능한 여섯 가지 경로별로 조건부 우도를 정의하였고 주변 우도를 구하기 위해 조정 가우스 구적법을 적용하였으며 뉴튼-랩슨 방법으로 최적 해를 구하였다. 모수의 95% 신뢰구간 포함률을 통해 제안한 방법의 소표본 성질을 살펴보기 위해 모의실험을 수행하였으며, Persones $Ag{\acute{e}}es$ Quid(PAQUID) 자료 (Helmer 등, 2001)에 제안한 모형을 적용하고 그 결과를 해석하였다.

Fouling behaviours of two stages microalgae/membrane filtration system applied to palm oil mill effluent treatment

  • Teow, Yeit Haan;Wong, Zhong Huo;Takriff, Mohd Sobri;Mohammad, Abdul Wahab
    • Membrane and Water Treatment
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    • 제9권5호
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    • pp.373-383
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    • 2018
  • Fouling by solids and microorganisms is the major obstacle limiting the efficient use of membrane wastewater treatment. In our previous study, two stages microalgae/membrane filtration system was proposed to treat anaerobic digested palm oil mill effluent (AnPOME). This two stages microalgae/membrane filtration system had showed great potential for the treatment of AnPOME with high removal of COD, $NH_3-N$, $PO_4{^{3-}}$, TSS, turbidity, and colour. However, fouling behavior of the membrane in this two stages microalgae/membrane filtration system was still unknown. In this study, empirical models that describe permeate flux decline for dead-end filtration (pore blocking - complete, intermediate, and standard; and cake layer formation) presented by Hermia were used to fit the experimental results in identifying the fouling mechanism under different experimental conditions. Both centrifuged and non-centrifuged samples were taken from the medium with 3 days RT intervals, from day 0 to day 12 to study their influence on fouling mechanisms described by Hermia for ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO) filtration mode. Besides, a more detailed study on the use of resistance-in-series model for deadend filtration was done to investigate the fouling mechanisms involved in membrane filtration of AnPOME collected after microalgae treatment. The results showed that fouling of UF and NF membrane was mainly caused by cake layer formation and it was also supported by the analysis for resistance-in-series model. Whereas, fouling of RO membrane was dominated by concentration polarization.

Finite element model updating effect on the structural behavior of long span concrete highway bridges

  • Altunisik, A.C.;Bayraktar, A.
    • Computers and Concrete
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    • 제14권6호
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    • pp.745-765
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    • 2014
  • In this paper, it is aimed to determine the finite element model updating effects on the structural behavior of long span concrete highway bridges. Birecik Highway Bridge located on the 81stkm of Sanliurfa-Gaziantep state highway over Firat River in Turkey is selected as a case study. The bridge consist of fourteen spans, each of span has a nearly 26m. The total bridge length is 380m and width of bridge is 10m. Firstly, the analytical dynamic characteristics such as natural frequencies and mode shapes are attained from finite element analyses using SAP2000 program. After, experimental dynamic characteristics are specified from field investigations using Operational Modal Analysis method. Enhanced Frequency Domain Decomposition method in the frequency domain is used to extract the dynamic characteristics such as natural frequencies, mode shapes and damping ratios. Analytically and experimentally identified dynamic characteristics are compared with each other and finite element model of the bridge is updated to reduce the differences by changing of some uncertain parameters such as section properties, damages, boundary conditions and material properties. At the end of the study, structural performance of the highway bridge is determined under dead load, live load, and dynamic loads before and after model updating to specify the updating effect. Displacements, internal forces and stresses are used as comparison parameters. From the study, it is seen that the ambient vibration measurements are enough to identify the most significant modes of long span highway bridges. Maximum differences between the natural frequencies are reduced averagely from %46.7 to %2.39 by model updating. A good harmony is found between mode shapes after finite element model updating. It is demonstrated that finite element model updating has an important effect on the structural performance of the arch type long span highway bridge. Maximum displacements, shear forces, bending moments and compressive stresses are reduced %28.6, %21.0, %19.22, and %33.3-20.0, respectively.

신뢰성을 고려한 도로 시거 설계의 제고 (Reliability-Based Design of Sight Distance, a Revisit)

  • 이슬기;이용재;김상기
    • 대한교통학회지
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    • 제24권1호
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    • pp.121-131
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    • 2006
  • 안전한 도로설계가 되기 위해서는 운전자나 자동차의 특성을 충실하게 반영한 설계기준을 사용하는 것이 필수적이다. 그러나, 기존의 설계기준들은 운전자와 차량의 체계에서 관측되는 불확실성의 특성을 감안하고 있지 못하며, 기본적으로 동질 단순 체계로 간주하여 대표적인 특성만을 반영하는 위험성이 있다. 본 연구에서는 도로선형설계의 가장 중요한 설계요소의 하나인 정지시거와 교차로시거를 중심으로 신뢰성을 기반으로 하는 새로운 방법을 제안하고자 한다. 연구를 위하여 신뢰성공학에서 이미 잘 알려진 Hasofer-Lind (1974)의 일계이차 모멘트 방법을 사용한다. 연구의 결과, 만약 특정 도로구간에 대하여 적용하고자 하는 시거모형의 파라메타에 대한 평균, 분산, 그리고 분포함수를 알 수 있다면 이를 이용하여 그 구간에 대한 시거의 불확실성과 안정성을 반영할 수 있는 새로운 설계기준을 만들 수 있음을 보여주고 있다 따라서, 본 연구에서 제안하고 있는 확률모형은 신뢰수준을 감안한 시거설계에 있어서 매우 유용할 것으로 생각된다.

수의의 금기에 관한 고찰 (An Inquiry into the Taboo of the Burial Shroud)

  • 남민이
    • 복식문화연구
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    • 제7권3호
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    • pp.50-57
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    • 1999
  • Folk belief, which originated with the rise of human existence is a fundamental and comprehensive mode of living that reflects sociocultural conditions. Adherents of folk belief accept a certain thing to be true and real without scientific authority and absolute certainty. Taboo can be seen as a king of folk belief. The object of this study is to examine the taboos in relation to the manufacturing process and the quality of the shroud and to shrouding customs. I will also try to find out the meaning and significance in this. Through this task, I hope to contribute to the enhanced understanding of the cultural characteristics, the spiritual life, and the views on after life of the Korean people. In Korea, it is considered to be propitious to prepare the shroud on the intercalary month of the leap year , as it allows one to enjoy longevity healthy and sound. Moreover, as this belief gives credence and repose while preparing for the “final departure”, this custom is relatively well observed. From the taboo concerning leap months, we infer that death as viewed as a commencement of a new life, which reveals a positive view on afterlife. This can be seen as a return to the origin of anti-universal space in this “bonus” month of anti-universal time. Taboos on the manufacturing process of the shroud is related to the belief that it allows the deceased to go the nest world without any hesistation or disturbances. This symbolizes the immortality of the human soul: I. e. that the human spirit does not end in this world but continues on to the next. Taboos concerning the preparation process of the shroud as well as various other taboos are related to the belief that preparation for the shroud should be done in sincerity and secredness with a thoughtful consideration for the deceased. This can be perceived as an implication to sanctity for the dead.

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Biodegradation of Aromatic Compounds by Nocardioform Actinomycetes

  • CHA CHANG-JUN;CERNIGLIA CARL E.
    • 한국미생물학회:학술대회논문집
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    • 한국미생물학회 2001년도 추계학술대회
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    • pp.157-163
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    • 2001
  • Mycolic acid-containing gram-positive bacteria, so called nocardioform actinomycetes, have become a great interest to environmental microbiologists due to their metabolic versatility, multidegradative capacity and potential for bioremediation of priority pollutants. For example, Rhodococcus rhodochrous N75 was able to metabolize 4-methy1catechol via a modified $\beta$-ketoadipate pathway whereby 4-methylmuconolactone methyl isomerase catalyzes the conversion of 4-methylmuconolactone to 3-methylmuconolactone in order to circumvent the accumulation of the 'dead-end' metabolite, 4-methylmuconolactone. R. rhodochrous N75 has also shown the ability to transform a range of alkyl-substituted catechols to the corresponding muconolactones. A novel 3-methylmuconolactone-CoAsynthetase was found to be involved in the degradation of 3-methylmuconolactone, which is not mediated in a manner analogous to the classical $\beta$-ketoadipate pathway but activated by the addition of CoA prior to hydrolysis of lactone ring, suggesting that the degradative pathway for methylaromatic compounds by gram-positive bacteria diverges from that of proteobacteria. Mycobacterium sp. Strain PYR-l isolated from oil-contaminated soil was capable of mineralizing various polyaromatic hydrocarbons (PAHs), such as naphthalene, phenanthrene, pyrene, fluoranthrene, 1-nitropyrene, and 6-nitrochrysene. The pathways for degradation of PAHs by this organism have been elucidated through the isolation and characterization of chemical intermediates. 2-D gel electrophoresis of PAH-induced proteins enabled the cloning of the dioxygenase system containing a dehydrogenase, the dioxygenase small ($\beta$)-subunit, and the dioxygenase large ($\alpha$)-subunit. Phylogenetic analysis showed that the large a subunit did not cluster with most of the known sequences except for three newly described a subunits of dioxygenases from Rhodococcus spp. and Nocardioides spp. 2-D gel analysis also showed that catalase-peroxidase, which was induced with pyrene, plays a role in the PAH metabolism. The survival and performance of these bacteria raised the possibility that they can be excellent candidates for bioremediation purposes.

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안동김씨모 출토 조선후기 원삼의 특징 (Charicteristics of Wonsam on An-dong Kim Clan's Tomb Relics in the later Chosun Dynasty)

  • 이태옥;김혜영;조우현
    • 한국의상디자인학회지
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    • 제7권2호
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    • pp.61-74
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    • 2005
  • Wonsam, a type of korean women's gown in Choseon Dynasty, was used as a small ceremonial costume for queens, crown princesses and princesses and as a grand ceremonial costume for royal concubines and wives of high rank officials. It was also worn as a wedding dress for commoners. In the families of illustrious officials, it was also used as burial accessories or garments for the dead. In this context, Wonsam is a formal dress for the people's most important four ceremonies of coming-of-age, marriage, funeral, and ancestor worship. It is worth emphasizing the costume since it was widely and importantly used by all ranks of women, from royal families to commoners. Through the Wonsam of An-dong Kim Clan's, we can see what the society was like at the end of Choseon Dynasty. First, a status system that strictly divided costumes for each class, was, in many parts, broken down. Second, the highly wrought patterns and texture of fabrics of the Wonsam reveal that it was granted from Court, or, if woven by the Kim family, it is considered to be produced by the Court's craftsman or through technical transfer, considering that the weaving skills used are as good as those in Courts. Third, regarding the precise needlework that is uncomparable to textiles used by other illustrious officials families, the Wonsam is considered to be granted from Court or, produced through the needlework skills that were handed down from needlewomen in Courts. The Wonsam of An-dong Kim Clan's has noble beauty in it, with outstanding weaving skills, fabrics, needlework and shape. Thus, it is no exaggeration to say that it has those qualities to be the standard costume that inherits the tradition of Korean people.

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철골보의 부동탄성처짐을 고려한 비합성데크 일방향 슬래브의 근사적인 휨모멘트 계수 평가 (Evaluation for Approximate Bending Moment Coefficients of Non-Composite Form Deck One-Way Slab considering Unequaled Elastic Deflection of Steel Beams)

  • 김호수;임영도
    • 한국강구조학회 논문집
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    • 제18권3호
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    • pp.373-383
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    • 2006
  • 거푸집용 데크 플레이트를 사용하는 일방향 슬래브는 구조형식상 4변을 강성이 다른 철골보로 지지된 플레이트 요소이지만 일반실무에서는 철근콘크리트구조 설계기준을 적용하여 일정폭을 가진 연속보로 간주하여 근사적인 해석법을 사용하고 있다. 거푸집용 비합성데크 일방향 슬래브를 지지하고 있는 철골보는 지지형태 및 위치에 따라 서로 다른 처짐이 발생되는 탄성지점으로서 지점별로 발생되는 휨모멘트 값큰 차이가 난다. 따라서, 본 연구는 단부의 부동처짐 효과를 고려한 근사해석법상의 휨모멘트 계수를 합리적으로 산정하기 위하여 다양한 해 석모델을 가정하였으며, 해석상의 변수로는 고정하중에 대한 활하중의 비율, 스팬별 활하중의 배열(패턴재하) 및 스팬길이를 고려하였다. 또한 해석방법으로 3차원 플레이트 유한요소해석, 이차원 탄성지점해석, 이차원 무한강성지점해석, 설계기준상의 근사해석을 각각 적용하여 결과값을 비교 분석하였다.

고품질 콘텐츠 제공환경하에서 인터넷 접속료 책정방안 (Internet Access Charging under High Quality Contents Delivery)

  • 정충영
    • 한국콘텐츠학회논문지
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    • 제17권11호
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    • pp.588-599
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    • 2017
  • 본 연구는 콘텐츠 제공자들이 자사의 콘텐츠를 보다 저렴한 비용과 높은 품질로 제공하기 위하여 이용자들이 가입되어 있는 ISP에게 직접 접속할 수 있는 다양한 기술을 적용할 경우, ISP들이 CP와 인터넷 가입자에게 망 혼잡에 따른 추가적인 접속료를 부과할 수 있다는 모형을 설정하고 분석한다. 이 경우 CP의 시장상황에 따라 ISP가 책정하는 접속료의 수준은 많이 달라질 것이다. CP가 경쟁적인 경우에는 이부제 요금을 적용하고 있는 ISP간 경쟁하에서 접속료는 CP요금과 함께 사회적 최적 상태와 동일하게 결정될 것이지만 CP가 독점적일 경우 ISP는 접속료에 대한 CP 요금 민감도에 따라 접속료 수준을 다르게 책정할 가능성이 있다. CP가 독점적인 경우 규제를 통해 사회후생의 왜곡을 치유할 수 있는데, 사회적 최적 접속료는 CP가 경쟁적인 경우보다 낮은 수준이다. 이는 CP가 독점적이므로 규제에 의해 접속료가 결정되면 그 접속료를 기반으로 CP가 한계비용보다 큰 요금을 결정하기 때문에 규제자는 접속료를 CP가 경쟁적일 때보다 낮게 책정하는 것이 사회후생을 더 증가시키게 된다.

Effect of rc Mutation on Semen Characteristics, Spermatogenic Tissues and Testosterone Profile in Blind Rhode Island Red Cockerels

  • Arshami, J.;Cheng, K.
    • Asian-Australasian Journal of Animal Sciences
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    • 제20권5호
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    • pp.701-705
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    • 2007
  • Seven rc mutant and seven normal male birds (Rhode Island Red suie, RIR) were used in this study to determine the effects of rc mutation on semen characteristics, testosterone profile and spermatogenic tissues. All birds were randomly selected at week 12 of age and housed in individual cages and were fed and watered ad libitum. The birds were exposed to a 14L:10D light cycle during experiment. Semen were collected at weeks 22 to 23 from each bird twice a week and evaluated for semen volume (SV), sperm concentration (SC), total sperm count (TSC), percent of sperm motility (%SM), dead sperm (%DS), and sperm metabolic activity (SMA). To determine the testosterone concentration (TC) in plasma, blood was collected at weeks 12, 16 and 18. Testicular tissue were collected, processed and evaluated for semineferous tubule diameter (STD), round spermatid number (RSN), percent elongated sperm (%ES) and semineferous tubules length (STL). Body weight (BW), comb weight (CW) and testes weight (TW) were weighted at the end of experiment (week 23). The SV, TSC and %SM were significantly higher in normal birds but the %DS was higher in blind birds (p<0.05). The SC did not differ significantly between the two groups but its value was higher in normal birds. The sperm metabolic activity in the first h of collection did not differ significantly between the two groups but after 24 h, the level of SMA in normal group was significantly higher (p<0.05). The level of TC did not differ significantly between the two genotype groups but normal birds had higher TC in all collections except the last one. The STD, RSN, %ES and STL in normal birds were higher when compared to blind birds but the differences were insignificant except for ES percent. The BW, CW and TW between the two groups did not differ significantly but the weights were higher in normal group compared to blind birds. Statistical analysis of semen characteristics, testosterone profile and histological factors were indicated detrimental effects of rc mutation in prepubertal RIR blind male birds due to lack of light.