• Structural Engineering and Mechanics
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• 제9권3호
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• pp.241-256
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• 2000

The major sources of energy dissipation in steel frames with partially restrained (PR) connections are evaluated. Available experimental results are used to verify the mathematical model used in this study. The verified model is then used to quantify the energy dissipation in PR connections due to hysteretic behavior, due to viscous damping and at plastic hinges if they are formed. Observations are made for two load conditions: a sinusoidal load applied at the top of the frame, and a sinusoidal ground acceleration applied at the base of the frame representing a seismic loading condition. This analytical study confirms the general behavior, observed during experimental investigations, that PR connections reduce the overall stiffness of frames, but add a major source of energy dissipation. As the connections become stiffer, the contribution of PR connections in dissipating energy becomes less significant. A connection with a T ratio (representing its stiffness) of at least 0.9 should not be considered as fully restrained as is commonly assumed, since the energy dissipation characteristics are different. The flexibility of PR connections alters the fundamental frequency of the frame. Depending on the situation, it may bring the frame closer to or further from the resonance condition. If the frame approaches the resonance condition, the effect of damping is expected to be very important. However, if the frame moves away from the resonance condition, the energy dissipation at the PR connections is expected to be significant with an increase in the deformation of the frame, particularly for low damping values. For low damping values, the dissipation of energy at plastic hinges is comparable to that due to viscous damping, and increases as the frame approaches failure. For the range of parameters considered in this study, the energy dissipations at the PR connections and at the plastic hinges are of the same order of magnitude. The study quantitatively confirms the general observations made in experimental investigations for steel frames with PR connections; however, proper consideration of the stiffness of PR connections and other dynamic properties is essential in predicting the dynamic behavior.

• 인터넷정보학회논문지
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• 제12권5호
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• pp.137-158
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• 2011

본 연구의 목적은 행정조직의 SNS 활용이 자치행정PR에 어떠한 영향을 미치는지 알고자 함에 있다. 오늘날 정보통신의 발달과 함께 SNS 서비스의 활성화로 자치행정PR에서도 SNS를 활용하고자 하는 행정조직이 늘고 있다. SNS의 활용은 과거 커뮤니케이션 메시지로 여론을 형성하고 조작하는 관점에서 이제는 시민과의 관계성을 관리하는 관점으로 바뀌어가고 있다. 이렇게 행정PR의 특성은 행정조직과 지역주민 사이의 관계성을 파악해야 함과 동시에 SNS가 이러한 관계성에 어떠한 영향을 미치는지 확인할 필요가 있다. 그러나 SNS의 특성을 확인하는 연구와 자치행정PR에 관한 연구는 별도로 진행되면서 SNS의 활용이 자치행정PR에 어떠한 효과를 가지고 있는지에 대한 연구는 전무하다. 이에 본 연구에서는 구청의 직원과 지역주민을 연구대상으로 하는 모델을 각각 설정하여 두 집단 간의 차이를 비교하고자 하였다. 본 연구의 결과, 행정조직의 SNS 활용은 지역주민의 피드백이 부족하였으며, 대다수 지역주민이 공감할 수 있는 주제 개발의 필요성을 제시하였다.

• 대한화학회지
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• 제38권9호
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• pp.660-666
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• 1994

이웃하는 란탄족 원소의 분리에서 온도와 흐름속도의 영향을 치환크로마토그래피로 연구하였다. 일렬로 연결된 두 컬럼에 Amberlite 120 양이온 교환수지를 채워서 충전용과 분리용으로 나누어 사용하였다. 보유이온은 $H^+$을, 흐름용액은 0.012M과 0.015M의 EDTA 용액을 사용하였다. 실험중에는 관의 온도를 90$^{\circ}C$로 유지하였으며 이온교환수지 관 속에 생기는 기포를 줄이기 위해 일정한 압력을 걸었다. 용출액은 ICP-AES로 직접 분석하였다. 이 실험에서 란탄족 원소쌍 La: Ce, Ce :Pr, Pr: Nd에 대한 분리인자는 각각 4.6, 2.8, 1.9이었으며 이것은 25$^{\circ}C$에서 이론적으로 얻은 것보다 큰 값이다. 흐름속도를 2.5 ml/min에서 1.5 ml/min로 줄이면 이론단해당높이(HETP)도 1.60 cm에서 0.88 cm로 줄었다. 따라서 용리액의 흐름속도를 줄이고 온도를 높이므로써 분리효율을 증가시킬 수 있었다. 이 실험에서 99.9% 이상의 순수 란탄족 원소에 대한 회수율은 49∼77%이었다.

• 대한원격탐사학회지
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• 제16권1호
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• pp.55-64
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• 2000

열대 강우 관측 위성(TRMM: Tropical Rainfall Measuring Mission)에서 관측된 자료가 한반도에서 발생한 호우 특성을 얼마나 잘 나타내 주는지를 알아보기 위하여 1998년과 1999년 여름철 호우 사례에 대해 분석하였다. 본 연구에서는 먼저 집중 호우를 동반한 비 구름대의 높이, 강수형태, 비 구름의 수직 분포 및 수평 단면도 상의 강우 분포를 조사하였으며, TRMM/PR 관측 강우 강도와 지상에서 관측된 자동기상관측 장비(AWS: Automatic Weather System)에서 관측된 값을 비교하였다. GMS-5 IR1과 AWS 지상관측 자료와 비교해 볼 때, TRMM/PR 관측자료는 기존의 자료로는 알 수 없는 강수 형태, 비 구름대의 높이 등에 대한 정보를 쉽게 제공해 주었으며 특히 비 구름대 내부에서의 강우강도 분포와 연직 발달 정도를 잘 묘사했다. 또한 위도-경도별 강우강도의 단면분포에서는 지형 효과에 의한 강우 특성도 알 수 있었다. TRMM/PR 관측 강우강도 값은 AWS 관측치에 비해 6 mm/hr 이하에서 더 많이 관측되었으며, 전체적으로는 지상 관측에 비해 적게 관측되는 경향을 보였다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.239-242
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• 2002

Luminescence efficiency of phosphors, $SrTiO_3;Pr^{3+}$ and $SrIn_2O_4:Pr^{3+}$, is increased remarkably by III-group impurities. This effect is explained by a picture that carriers thermally released from impurity-induced traps supply energy to $Pr^{3+}$ ions. The impurities also improve carrier transport efficiency by reducing lattice defects. This picture indicates a possibility to develop new ternary oxide phosphors.

• 한국통신학회:학술대회논문집
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• 한국통신학회 1983년도 추계학술발표회논문집
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• pp.97-101
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• 1983

A Study is presented showing the effect of carrier phase error on the error-rate of a PR shaped SQAM digital radio system. A simple upper bound on the probability of error as a function of phase error is derived and compared to one another. The result is that if carrier phase error is less than 3 there is no serious degradation.

• 자원리싸이클링
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• 제26권4호
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• pp.79-87
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• 2017

Cyanex 572에 의한 경희토류 다성분 혼합 용액에서 La, Ce, Pr, Nd, Sm의 분리특성에 대해 연구하였다. 5성분계 혼합 용액에서 추출제 농도가 증가할수록 5성분 모두 $pH_{50}$(추출율이 50%인 pH) 값은 감소하였다. 추출제 농도 0.6 M 이상에서 La과 Ce, Nd와 Sm 는 10 이상의 분리계수 값을 보인 반면, Ce과 Pr, Pr과 Nd 사이의 분리계수는 0.5~2.2로 낮았다. 분리계수 개선을 위해 0.6 M Cyanex 572에 TBP를 첨가하였으나 상 분리 속도나 분리계수 개선 효과는 나타나지 않았다. 실험 결과를 고찰한 결과, La/(Pr, Nd, Sm) 그룹과 (Pr, Nd)/Sm 의 경우는 그룹 별 분리는 가능할 것으로 보이나, (La, Ce) 과 (Pr, Nd)의 그룹분리는 Ce와 Pr 사이의 분리계수가 낮아 어려울 것으로 사료된다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권11호
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• pp.4791-4795
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• 2015

Purpose: This study was conducted to observe the efficacy and safety of pemetrexed based chemotherapy in treating patients with locally advanced or metastatic cancers as first-line, second-line or third-line therapy. Materials and Methods: From May 2011 to January 2015, we recruited 29 patients with advanced breast cancer, 19 patients with advanced ovary cancer, 17 patients with advanced esophageal cancer,5 patients with advanced gallbladder cancer,5 patients with advanced cervical cancer and 1 patient with advanced tongue cancer in Jiangsu Cancer Hospital and Research Institute.All of them were pathologically confirmed and treated with pemetrexed based chemotherapy. After two cycles of treatment,efficacy and safety can be evaluated. Results: For pemetrexed based regimens,including 76 patients with 6 kinds of advanced cancer were considered eligible for inclusion. Complete remission represents CR, partial remission represents PR, stable disease represents SD, progressive disease represents PD. Among 29 patients with advanced breast cancer, 4 patients chose pemetrexed based regimens as second-line treatment,1 of them was PR,the other 3 got SD. The last 25 patients made use of this chemotherapy as third-line treatment, except one patient could not be assessed, 2 of them got PR,6 of them got SD,the remaining 16 of them finally were PD.19 patients with advanced ovary cancer,5 patients used this regimens as second-line treatment, 3 of them got PD,the remaining patients got SD, respectively. The last 14 patients made use of pemetrexed based regimens as third-line treatment,. RR (CR+PR) was 28.5%. Among 17 patients with advanced esophageal cancer, 2 patients made use of pemetrexed based regimens as first-line treatment,both of them got PR.4 of them used this chemotherapy as second-line regimen, except 2 patients could not be assessed,the remaining 2 was PD at last. The last 11 patients was third-line users, RR (CR+PR) was 18.2%. Among 5 patients with advanced gallbladder cancer, pemetrexed based regimens was used in 1 patient as first-line treatment and 1 patient as second-line treatment. The curative effect was SD and PD, respectively. 3 patients accepted pemetrexed based regimens as third-line treatment, 2 of them got PD as results and another was SD. Among 5 patients with advanced cervical cancer, just 1 patient adopted pemetrexed based regimens as first-line treatment, whose curative effect was PR.2 patients chose this chemotherapy regimens as second-line treatment. Both of them got PD as their consequence. The last 2 patients made use of the regimens as third-line treatment, the effect of them was PD and SD, respectively. The one who with advanced tongue cancer, pemetrexed based regimens was used as second-line treatment, and the consequence was PD. About 71.1% patients experienced bone marrow suppression. Among them, 5 patients reached 4 grade. Other toxicity of pemetrexed were neurotoxicity, fatigue, diarrhea, dysphagia and vomiting. No treatment related death occurred with pemetrexed-based treatment. Conclusions: Pemetrexed based chemotherapy has considerable effect in patients with advanced cancers such as breast cancer,esophageal cancer and ovary cancer. More randomly clinical trials are needed to verify the results.

• IMMUNE NETWORK
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• 제13권4호
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• pp.148-156
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• 2013

The $PrP^C$ is expressed in many types of immune cells including monocytes and macrophages, however, its function in immune regulation remains to be elucidated. In the present study, we examined a role for $PrP^C$ in regulation of monocyte function. Specifically, the effect of a soluble form of $PrP^C$ was studied in human monocytes. A recombinant fusion protein of soluble human $PrP^C$ fused with the Fc portion of human IgG1 (designated as soluble $PrP^C$-Fc) bound to the cell surface of monocytes, induced differentiation to macrophage-like cells, and enhanced adherence and phagocytic activity. In addition, soluble $PrP^C$-Fc stimulated monocytes to produce pro-inflammatory cytokines such as $TNF-{\alpha}$, $IL-1{\beta}$, and IL-6. Both ERK and $NF-{\kappa}B$ signaling pathways were activated in soluble $PrP^C$-treated monocytes, and inhibitors of either pathway abrogated monocyte adherence and cytokine production. Taken together, we conclude that soluble $PrP^C$-Fc enhanced adherence, phagocytosis, and cytokine production of monocytes via activation of the ERK and $NF-{\kappa}B$ signaling pathways.

• Asian Pacific Journal of Cancer Prevention
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• 제15권21호
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• pp.9233-9239
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• 2014

Background: We aimed to evaluate the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) expression discordance in matched pairs of primary breast cancer and lymph node metastasis specimens and determine the effect of discordance on prognosis. Materials and Methods: Among all patients diagnosed with lymph node metastases from 2004 to 2007, primary tumors and paired lymph node metastases were resected from 209 patients. The status of ER, PR, and HER2 expression was analyzed immunohistochemically in 200, 194, and 193 patients, respectively. Discordance was correlated with prognosis. Results: Biomarker discordance between primary tumors and paired lymph node metastases was 25.0% (50/200) for ER status, 28.9% (56/194) for PR status, and 14.0% (27/193) for HER2 status. ER positivity was a significant independent predictor of improved survival when analyzed in primary tumors and lymph node metastases. Patients with PR-positive primary tumors and paired lymph node metastases displayed significantly enhanced survival compared to patients with PR-positive primary tumors and PR-negative lymph node metastases. Patients with ER- and PR-positive primary tumors and paired lymph node metastases who received endocrine therapy after surgery displayed significantly better survival than those not receiving endocrine therapy. Similalry treated patients with PR-negative primary tumors and PR-positive paired lymph node metastases also displayed better survival than those not receiving endocrine therapy. Conclusions: Biomarker discordance was observed in matched pairs of primary tumors and lymph node metastases. Such cases displayed poor survival. Thus, it is important to reassess receptor biomarkers used for lymph node metastases.