• 제목/요약/키워드: non-existence

검색결과 936건 처리시간 0.033초

다중 지역기후모델로부터 모의된 월 기온자료를 이용한 다중선형회귀모형들의 예측성능 비교 (Inter-comparison of Prediction Skills of Multiple Linear Regression Methods Using Monthly Temperature Simulated by Multi-Regional Climate Models)

  • 성민규;김찬수;서명석
    • 대기
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    • 제25권4호
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    • pp.669-683
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    • 2015
  • In this study, we investigated the prediction skills of four multiple linear regression methods for monthly air temperature over South Korea. We used simulation results from four regional climate models (RegCM4, SNURCM, WRF, and YSURSM) driven by two boundary conditions (NCEP/DOE Reanalysis 2 and ERA-Interim). We selected 15 years (1989~2003) as the training period and the last 5 years (2004~2008) as validation period. The four regression methods used in this study are as follows: 1) Homogeneous Multiple linear Regression (HMR), 2) Homogeneous Multiple linear Regression constraining the regression coefficients to be nonnegative (HMR+), 3) non-homogeneous multiple linear regression (EMOS; Ensemble Model Output Statistics), 4) EMOS with positive coefficients (EMOS+). It is same method as the third method except for constraining the coefficients to be nonnegative. The four regression methods showed similar prediction skills for the monthly air temperature over South Korea. However, the prediction skills of regression methods which don't constrain regression coefficients to be nonnegative are clearly impacted by the existence of outliers. Among the four multiple linear regression methods, HMR+ and EMOS+ methods showed the best skill during the validation period. HMR+ and EMOS+ methods showed a very similar performance in terms of the MAE and RMSE. Therefore, we recommend the HMR+ as the best method because of ease of development and applications.

Postnatal Expressional Patterns of Adipose-Associated Molecules in the Mouse Proximal Epididymal Fat

  • Lee, Ki-Ho
    • 한국발생생물학회지:발생과생식
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    • 제23권4호
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    • pp.313-322
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    • 2019
  • The epididymal fat pad is a male gonadal adipocyte tissue and is histochemically separated into distal and proximal parts. The development of epididymal fat during postnatal period has not been examined in detail. A previous research showed that expression of adipocyte-associated molecules in the distal epididymal fat of mouse is generally increased as postnatally aged. In the present study, expressional patterns of same adipocyte-associated molecules in the mouse proximal epididymal fat at 2, 5, 8, and 12 months of age were studied by quantitative real-time PCR analysis and were compared with those in the distal epididymal fat. The expressional levels of peroxisome proliferator-activated receptor gamma (Pparg), lipoprotein lipase (Lpl), and fatty acid synthase (Fasn) at 5 months of age were significantly lower than those at 2 months of age, while transcript level of leptin (Lep) at 5 months was higher than that at 2 months of age. The transcript levels of all molecules at 8 months of age were significantly increased, compared with those at 2 and 5 months of age. At 12 months of age, expression of delta like non-canonical Notch ligand 1 (Dlk1) was further significantly increased, while there was no change on the transcript level of Pparg and significant decreases of Fabp4, Retn, Lpl, Lep, Fasn, and adiponectin (Adipoq) transcript levels. The current findings show that expressional patterns of molecules associated with adipocyte in the proximal epididymal fat is somewhat different with those of the distal epididymal fat, suggesting the existence of regional variance in the epididymal fat.

미만성 축삭 손상에서 전산화단층촬영과 경사에코 자기공명영상을 이용한 예후의 평가 (Prognostic Value of Computed Tomography and Gradient-echo Magnetic Resonance Imaging in Diffuse Axonal Injury)

  • 정남기;진상찬;최우익
    • Journal of Trauma and Injury
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    • 제25권4호
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    • pp.122-131
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    • 2012
  • Purpose: Diffuse axonal injury (DAI) is clinically defined as a coma of over six hours in a head trauma victim without a focal mass lesion. The emergency physician usually resuscitates and stabilizes a comatose head trauma victim in the emergency Department. After assessment and treatment, the prognosis is very important to both the victim and the physician. The prognosis for DAI is based on Glasgow Coma Scale (GCS) and other imaging data. We investigated the prognostic value of computed tomography (CT) and gradient-echo magnetic resonance imaging (GRI) for head trauma victims with DAI. Methods: Fifty-three(53) head trauma victims of DAI were enrolled in this study from 2007 to 2012. During the study period of six years, data on trauma victims were collected retrospectively. We analyzed the differences in the Glasgow Outcome Scale (GOS) result between the CT and the GRI modalities. Results: We classified the study group by using GOS. Between the good outcome subgroup (GOS scores of 4 and 5) and the poor outcome subgroup (GOS score of 1-3), there were no statistical difference in sex, age, initial vital signs and initial GCS score. The good outcome subgroup had non-hemorrhage on CT(52%), which was correlated with good outcome and a shorter awakening time, while a larger number and a deeper location of hemorrhagic lesions on in GRI were correlated with poor outcome in DAI. Conclusion: We conclude that the existence of hemorrhagic lesions on CT, and the number and location of those lesions on GRI had good prognostic value for head trauma victims with DAI.

재래시장에서의 화재조건에 따른 스프링클러설비의 소화성능변화와 화재특성에 관한 연구 (A Study on Features of Fire and Change of Extinguishing Capacity of Sprinkler Equipment Against Fire at a Traditional Market)

  • 박진우;전규엽;나욱정;홍원화
    • 한국화재소방학회논문지
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    • 제22권1호
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    • pp.128-138
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    • 2008
  • 소규모 점포가 밀집한 재래시장에 적재된 물품은 고무, 합성섬유제품, 플라스틱 등으로 대부분이 화재발생시 높은 열량을 방출하여 인접 가연물에 쉽게 착화되는 경향이 있다. 또한 점포간에 방화구획이 마련되지 않고 커튼과 같은 가연성물질로 구획되어 화재가 대형화될 수 있는 실정이다. 따라서 낙후된 재래시장의 화재위험성, 취약요인을 분석하고 화재발생시 가장위험하다고 판단되는 점포칸막이의 유무 가연물의 적재 높이 등을 화재 시 위험요소로 설정하여 Field 모델링이 가능한 화재시뮬레이션을 활용하여 스프링클러설비의 소화성능변화와 화재특성을 분석하였다. 그 결과 점포칸막이, 가연물의 적재높이 등은 스프링클러 살수반경에 장애요인으로 작용하여 화재의 크기 및 온도분포를 증가시키는 요인으로 나타났다.

Hollow core 슬래브 간 접합부의 전단저항성능 평가 (Shear Performance Evaluation of the Joint between Hollow Core Slabs)

  • 홍건호;백종삼;박홍근
    • 한국구조물진단유지관리공학회 논문집
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    • 제14권4호
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    • pp.94-101
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    • 2010
  • 최근 건설공사의 공기단축을 위하여 프리캐스트 콘크리트(Precast Concrete)에 대한 관심이 점차 증가하는 추세이다. 본 연구에서는 프리캐스트 콘크리트 중 내부에 중공을 설치하여 중량을 감소시킨 할로우코어 슬래브 간의 접합부 전단성능 평가에 대한 실험적 연구를 수행하였다. 실험의 주요 변수는 할로우코어 슬래브 상부의 토핑콘크리트의 두께와 와이어메쉬의 배근유무이며, 총 8개의 슬래브간 접합부 실험체 중 4개의 면내전단실험과 4개의 면외방향 전단실험을 수행하였다. 실험의 결과는 균열하중, 파괴하중, 파괴양상, 강성 및 연성도의 측면에서 분석하였으며, 실험결과를 설계하중과 비교 검토함으로써 최적의 디테일을 개발할 수 있는 실험적 근거를 제공하도록 하였다. 실험결과, 슬래브 간 접합부에 무수축 모르타르를 타설한 경우에는 토핑두께 30mm의 보통 콘크리트를 사용한 것과 유사한 구조성능을 발현할 수 있는 것으로 평가되었으며, 와이어메쉬의 보강효과는 내력 및 강성보다는 연성의 증가에 크게 기여하는 것으로 나타났다. 또한, 토핑콘크리트의 두께에 따른 설계하중과의 비교를 통하여 적절한 디테일 설계를 할 수 있는 기초적 자료를 제공하였다.

셀리언시가 높은 물체가 게임 난이도에 미치는 영향 (The Influence of Salient Objects on the Game Difficulties)

  • 이지형;이찬근;이창하
    • 한국게임학회 논문지
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    • 제10권1호
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    • pp.15-23
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    • 2010
  • 슈팅 게임이나 플랫폼 게임과 같은 액션 게임에서는 플레이어 캐릭터가 적 캐릭터와 충돌하면 플레이어 캐릭터가 죽거나 에너지가 감소하게 되므로 적 캐릭터를 회피하는 요소가 중요하다. 본 논문에서는 적 캐릭터를 회피하는 요소가 중요한 게임에서 셀리언시(saliency)가 높은 물체가 있을 경우 게임의 난이도에 어떠한 영향을 미치는가에 대하여 고찰하였다. 플레이어는 셀리언시가 높은 물체의 움직임을 주목하게 되므로 이로 인해 셀리언시가 낮은 다른 많은 물체들의 움직임을 간과할 수 있다. 그 결과로 물체의 회피에 실패할 확률이 높아질 것이다. 본 연구에서는 셀리언시가 높은 물체의 존재여부가 게임 난이도에 미치는 영향을 검증하기 위해 사용자 실험을 수행하였으며, 셀리언시가 높은 물체가 없는 게임을 수행한 그룹이 셀리언시가 높은 물체가 있는 게임을 수행한 그룹보다 더 높은 점수를 획득하는 결과를 얻었다. 본 연구는 인간의 지각적인 측면에서 게임의 난이도에 영향을 끼칠 수 있는 요소를 살펴보고 이를 실험을 통해 검증하였고 이는 게임 제작 및 기획 단계에서 난이도 예측에 도움이 되는 요소가 될 수 있을 것이다.

초등 1학년 발달성 난독 아동의 낱말 해독, 음운인식, 빠른 이름대기, 자소 지식 (Korean first graders' word decoding skills, phonological awareness, rapid automatized naming, and letter knowledge with/without developmental dyslexia)

  • 양유나;배소영
    • 말소리와 음성과학
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    • 제10권2호
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    • pp.51-60
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    • 2018
  • This study aims to compare the word decoding skills, phonological awareness (PA), rapid automatized naming (RAN) skills, and letter knowledge of first graders with developmental dyslexia (DD) and those who were typically developing (TD). Eighteen children with DD and eighteen TD children, matched by nonverbal intelligence and discourse ability, participated in the study. Word decoding of Korean language-based reading assessment(Pae et al., 2015) was conducted. Phoneme-grapheme correspondent words were analyzed according to whether the word has meaning, whether the syllable has a final consonant, and the position of the grapheme in the syllable. Letter knowledge asked about the names and sounds of 12 consonants and 6 vowels. The children's PA of word, syllable, body-coda, and phoneme blending was tested. Object and letter RAN was measured in seconds. The decoding difficulty of non-words was more noticeable in the DD group than in the TD one. The TD children read the syllable initial and syllable final position with 99% correctness. Children with DD read with 80% and 82% correctness, respectively. In addition, the DD group had more difficulty in decoding words with two patchims when compared with the TD one. The DD group read only 57% of words with two patchims correctly, while the TD one read 91% correctly. There were significant differences in body-coda PA, phoneme level PA, letter RAN, object RAN, and letter-sound knowledge between the two groups. This study confirms the existence of Korean developmental dyslexics, and the urgent need for the inclusion of a Korean-specific phonics approach in the education system.

국내 WCDMA 서비스의 시장확산과 마케팅전략 영향요인 (Factors Influencing the Market Diffusion and Marketing Strategy of WCDMA Service)

  • 김문구;박종현;남찬기
    • 한국통신학회논문지
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    • 제30권8B호
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    • pp.569-580
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    • 2005
  • 차세대 이동통신인 WCDMA서비스는 시장 불확실성, 유효수요 부족, 급격한 기술진화, 사업의지 및 전략 미흡, 경쟁서비스와의 차별성 부족, 킬러 애플리케이션 부재 등으로 인하여 국내 시장성장이 지연되고 있는 실정이다. 이에 본 연구에서는 WCDMA의 본격적인 시장활성화를 위하여 시장확산과 마케팅전략의 영향요인을 분석하고자하였다. 이를 위해 전문가 조사를 통하여 WCDMA 시장확산을 위한 성장의 동인이 되는 촉진요인과 해결과제가 되는 장애요인을 도출하였다. 그리고 설문조사를 바탕으로 WCDMA 마케팅전략 결정의 영향요인이 되는 이용요인, 지불의사수준, 킬러 애플리케이션, 선호 단말기, 유망 고객군을 규명하였다. 이를 바탕으로 WCDMA의 고객전략, 요금전략, 서비스 및 단말기 제공전략, 포지셔닝전략 등을 중심으로 마케팅 전개방향을 제시하였다.

급성 endosulfan 중독환자에서 경련이 예후에 미치는 영향 (Effect of Seizure on Prognosis in Acute Endosulfan Intoxication)

  • 한병곤;이준호;이경우
    • 대한임상독성학회지
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    • 제7권2호
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    • pp.77-82
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    • 2009
  • Purpose: In highly doses, endosulfan lowers the seizure threshold and elicits central nervous system stimulation, which can result in seizures, respiratory failure, and death. Management of seizure control is essential for survival and prognosis of intoxicated patients. This study assessed whether seizure time was an independent predictor mortality in patients with endosulfan poisoning. Methods: This retrospective study enrolled patients with endosulfan poisoning presenting to Masan Samsung Hospital and Gyeongsang National University Hospital from January 2003 to December 2008. The data were collected from clinical records and laboratory files. Using a multivariate logistic analysis, data on the total population was retrospectively analyzed for association with mortality. Results: Of the 24 patients with endosulfan poisoning, nineteen (79.1%) experienced seizure. The patients in the seizure group showed significantly lower Glasgow coma scale score, base excess, bicarbonate, and significant existence of mechanical ventilation, as compared to the non seizure group (n=5). Seizure, Glasgow coma scale score, systolic blood pressure, bicarbonate level, need for respiratory support, pulse rate, respiratory rate, pH, base excess, and seizure time were associated with mortality. The fatality rate of endosulfan poisoning was 54.1% with higher mortality among patients experiencing. Longer seizure time was associated with higher mortality. Conclusion: Seizure time can be a significant independent predictor of mortality in patients with acute endosulfan poisoning. Physicians should aggressively treat for seizure control in patients with acute endosulfan poisoning.

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Thermal Denaturation of the Apo-cyclic AMP Receptor Protein and Noncovalent Interactions between Its Domains

  • Won, Hyung-Sik;Seo, Min-Duk;Ko, Hyun-Suk;Choi, Wahn Soo;Lee, Bong-Jin
    • Molecules and Cells
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    • 제26권1호
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    • pp.61-66
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    • 2008
  • Cyclic AMP receptor protein (CRP) is allosterically activated by cAMP and functions as a global transcription regulator in enteric bacteria. Structural information on CRP in the absence of cAMP (apo-CRP) is essential to fully understand its allosteric behavior. In this study we demonstrated interdomain interactions in apo-CRP, using a comparative thermodynamic approach to the intact protein and its isolated domains, which were prepared either by limited proteolysis or using recombinant DNA. Thermal denaturation of the intact apo-CRP, monitored by differential scanning calorimetry, revealed an apparently single cooperative transition with a slight asymmetry. Combined with circular dichroism and fluorescence analysis, the thermal denaturation of apo-CRP could be interpreted as a coupled process involving two individual transitions, each attributable to a structural domain. When isolated individually, both of the domains exhibited significantly altered thermal behavior, thus pointing to the existence of non-covalent interdomain interactions in the intact apo-CRP. These observations suggest that the allosteric conformational change of CRP upon binding to cAMP is achieved by perturbing or modifying pre-existing interdomain interactions. They also underline the effectiveness of a comparative approach using calorimetric and structural probes for studying the thermodynamics of a protein.