• 한국소음진동공학회논문집
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• 제16권11호
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• pp.1132-1139
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• 2006

Non-contact underwater explosions against surface ship could cause extensive equipment damage during wartime service. Thus, the need to develop methods for the design of shock resistant equipment structures and systems was strongly established. In analytical methods, DDAM(Dynamic Design and Analysis Method) and transient repsonse method are used for ship shock design. In this paper, to analyze the characteristics of DDAM, medium weight shock test, DDAM and transient response analysis for missile system equipment are performed.

• 한국포장학회지
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• 제11권1호
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• pp.17-24
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• 2005

During handling unitized products, they are subjected to a variety environmental hazards. Shock and vibration hazards are generally considered the most damaging of the environmental hazards on a product, and it may encounter while passing through the distribution environment. A major cause of shock damage to products is drops during manual handling. The increasing use of unitization on pallets has been resulted in a reduction in the manual handling of products and with it a reduction in the shock hazards. This has caused and increasing interest in research focused on vibration caused damage. the use of pallets as a base for unitizing loads, aids in the mechanical handling, transportation and storage of products. Besides aiding in the handling, transportation and storage of products, a pallet also acts on and interface between the packaged goods and the distribution environment. The determination of the impact deformation of the cushioning materials such as tray cup (polymeric foam) and corrugated fiberboard pad must be carried out to design the proper packaging system providing adequate protection for the fruit, and to understand the complex interaction between the components of fruit when they relate to expected transportation vibration inputs. In this study, the theoretical analysis of impact deformation for cushioning materials by dynamic vibration. The impact deformations of SW and DW corrugated fiberboard pad in acceleration amplitudes of 0.25 G-rms and 0.5 G-rms that were usually generated in transport vehicles during distribution environments were very small compare with the thickness of corrugated fiberboard pad. The maximum of vibration acceleration level of tray cup by vibration impact was about 3.2 G-rms. The theoretical allowable acceleration (G-factor) of the pear was 0.7102 G-rms, and the maximum dynamic deformation estimated within G-factor was about 1 mm.

• 약학회지
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• 제51권1호
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• pp.44-50
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• 2007

Acute septic shock is one of inflammatory diseases mediated by pro-inflammatory cytokines such as tumor necrosis factor (TNF)-${\alpha}$. In this study, we examined the pathological difference and mechanism of lipopolysaccharides isolated from E. coli (E-LPS) or S. abortus (S-LPS) on inducing acute septic shock in ICR mouse. All mice were died by intraperitoneal treatment of S-LPS with 0.75 mg/kg, whereas E-LPS treated with even 3 mg/kg only showed 30% of mice lethal, indicating that S-LPS may be more feasible in triggering a strong septic shock condition. The secretion pattern of TNF-${\alpha}$, a critical pro-inflammatory cytokine in septic shock condition, was also distinct between E-LPS- and S-LPS-treated groups. Thus, S-LPS strikingly increased serum level of TNF-${\alpha}$ (6 ng/ml) at 1 h, while E-LPS just displayed at 2 ng/ml level. However the interaction of S-LPS with LPS receptor toll like receptor (TLR)-4, was not stronger than that of E-LPS, according to experiments with macrophage cell line RAW264.7 cells. Thus, E-LPS rather than S-LPS strongly enhanced the production of TNF-${\alpha}$. Interestingly, S-LPS more strongly up-regulated splenocyte proliferation, compared to E-LPS group, whereas there was no difference between S- or E-LPS treated groups in proliferation of Balb/c- or C57BL/6-originated splenic lymphocytes. Therefore, our data suggest that S-LPS is a more active endotoxin and that the strong septic shock-inducing effect of S-LPS seems due to the enhancement of early TNF-${\alpha}$ production and S-LPS-sensitive lymphocyte proliferation.

• 에너지공학
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• 제21권1호
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• pp.26-32
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• 2012

본 연구에서는 PV(photovoltaic)모듈에서 경년에 따른 효율 저하의 원인을 분석하기 위해 셀 레벨에서의 열충격 시험을 수행하였다. 열충격 시험의 조건은 $-40^{\circ}C$에서 $85^{\circ}C$로 각각 15분씩 30분을 1사이클로 하였으며, 열충격 시험 500 사이클 동안 100 사이클 간격으로 EL분석 및 I-V분석을 수행하였다. 효율 감소율은 단결정 Bare Cell이 8%, Solar Cell이 9%였으며, 다결정 Bare Cell이 6%, Solar Cell이 13%의 감소율을 보였다. 열충격 시험 후 Solar Cell은 표면 손상으로 인한 효율저하를 확인할 수 있었다. Bare Cell의 경우 표면의 손상이 없었지만, 효율이 저하된 것을 확인할 수 있었다. 이는 Fill Factor 분석에 의해 경년 시 나타나는 누설전류에 의한 소모전력 증가로 효율 저하에 영향을 준 것으로 판단된다. 또한, Bare Cell보다 Solar Cell에서의 효율 감소율이 상대적으로 높게 나타난 결과는 표면 손상 및 소모 전력의 증가로 인해 Solar Cell 효율에 큰 영향을 미치는 것으로 판단된다. 향후 단면 분석법 및 다양한 조건의 시험 기법을 활용하여 PV모듈 뿐 아니라 Cell 레벨에서의 불규칙한 효율 및 Fill Factor의 감소 원인을 검토하고, Solar Cell에서의 효율 저하가 가속되는 원인에 대한 대책 방안 연구가 수행되어야 할 것이다.

• Structural Engineering and Mechanics
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• 제37권3호
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• pp.257-265
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• 2011

Plant-specific analyses of 5 types of domestic reactors in Korea are performed to assure the structural integrity of the reactor pressure vessel (RPV) during transients which are expected to initiate pressurized thermal shock (PTS) events. The failure probability of the RPV due to PTS is obtained by performing probabilistic fracture mechanics analysis. The through-wall cracking frequency is calculated and compared to the acceptance criterion. Considering the fluence at the end of life expected by surveillance test, the sufficient safety margin is expected for the structural integrity of all reactor pressure vessels except for the oldest one during the pressurized thermal shock events. If the flaw with aspect ratio of 1/12 is considered to eliminate the conservatism, the acceptance criteria is not exceeded for all plants until the fluence level of $8{\times}10^{19}\;n/cm^2$, generating sufficient margin beyond the design life.

• The Korean Journal of Physiology and Pharmacology
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• 제22권4호
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• pp.457-465
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• 2018

The expression of BCL-2 interacting cell death suppressor (BIS), an anti-stress or anti-apoptotic protein, has been shown to be regulated at the transcriptional level by heat shock factor 1 (HSF1) upon various stresses. Recently, HSF1 was also shown to bind to BIS, but the significance of these protein-protein interactions on HSF1 activity has not been fully defined. In the present study, we observed that complete depletion of BIS using a CRISPR/Cas9 system in A549 non-small cell lung cancer did not affect the induction of heat shock protein (HSP) 70 and HSP27 mRNAs under various stress conditions such as heat shock, proteotoxic stress, and oxidative stress. The lack of a functional association of BIS with HSF1 activity was also demonstrated by transient downregulation of BIS by siRNA in A549 and U87 glioblastoma cells. Endogenous BIS mRNA levels were significantly suppressed in BIS knockout (KO) A549 cells compared to BIS wild type (WT) A549 cells at the constitutive and inducible levels. The promoter activities of BIS and HSP70 as well as the degradation rate of BIS mRNA were not influenced by depletion of BIS. In addition, the expression levels of the mutant BIS construct, in which 14 bp were deleted as in BIS-KO A549 cells, were not different from those of the WT BIS construct, indicating that mRNA stability was not the mechanism for autoregulation of BIS. Our results suggested that BIS was not required for HSF1 activity, but was required for its own expression, which involved an HSF1-independent pathway.

• 유통과학연구
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• 제22권3호
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• pp.105-112
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• 2024

Purpose: This study analyzed the relationship between corporate capacity and management performance in the Korean distribution industry during the COVID-19 pandemic. Research design, data and methodology: The data for this study used the 2021 KOTRA GCL Test Data, and multiple regression analysis was performed using SPSS 26. As corporate competency, human capital and related capital of intellectual capital theory were utilized, and the global network level of social network theory was also utilized. As an additional analysis, corporate characteristics factors were used. Results: First, the level of global mindset of human capital acted as a positive factor in management performance, and the level of professional manpower did not achieve significant results. Second, related capital acted as a positive factor in corporate performance. Third, from the perspective of social network theory, the global network level of companies acted as a positive factor in management performance. Finally, the relationship between corporate characteristics and management performance was marginally significant. Conclusions: In order to improve the business performance of a company in a market shock such as the COVID-19 pandemic, it is required to strengthen the level of network construction with customers and increase the level of intellectual capital that a company has.

• 대한화장품학회지
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• 제48권2호
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• pp.157-167
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• 2022

본 연구에서는 7 개의 아미노산으로 이루어진 헵타펩타이드의 섬유아세포 활성 증가 및 광노화 조건에서의 세포 손상 억제 효과를 확인하였다. 실험 결과 헵타펩타이드 처리 시 섬유아세포 증식 및 세포외기질(extracellular matrix, ECM) 구성 인자의 발현이 증가되었다. 그리고 자외선 A (ultraviolet A, UVA) 조사에 의해 유도된 광노화조건에서 감소된 세포 생존율이 헵타펩타이드에 의해 증가되었고, UVA 조사에 의해 유도된 세포 사멸, 기질금속단백질분해효소-1(matrix metalloproteinases-1, MMP-1) 발현 및 세포 내 활성산소종(reactive oxygen species, ROS) 수준이 헵타펩타이드에 의해 감소되었다. UVA 조사 시 나타나는 transforming growth factor-β (TGF-β)/smad 기전 억제와 그에 따른 ECM 구성 인자 발현 감소 또한 헵타펩타이드에 의해 회복되었다. 또 다른 광노화 유도 조건으로 heat shock을 주었고 헵타펩타이드를 전 처리 하였을 때 heat shock에 의한 mitogen-activated protein kinase (MAPK) 인산화 및 MMP-1 발현이 억제됨을 확인할 수 있었다. 이 결과를 종합해 볼 때, 본 연구의 헵타펩타이드는 섬유아세포의 활성을 촉진하며, 광노화 유도 모델로 사용된 UVA 조사 및 heat shock 조건에서도 세포 내 ROS 억제 효과를 보여 세포 손상에 대한 회복 및 보호 효과를 나타내는 것으로 보인다. 이러한 진피 보호 효과를 갖는 헵타펩타이드는 향 후 신규 화장품 소재로 응용될 수 있을 것으로 기대된다.

• 한국심리학회지 : 문화 및 사회문제
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• 제21권1호
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• pp.45-66
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• 2015

본 연구에서는 해외유학경험 후 귀국한 성인들의 재문화충격 경험과 주관적 안녕감을 알아보고, 지지체계(가족지지, 모국친구지지, 외국친구지지)와 문화정체성(모국정체성, 외국정체성)이 재문화충격과 주관적 안녕감의 관계를 조절하는지를 살펴보았다. 연구참여자들은 19세 이전에 한국을 떠나 해외에서 3년 이상 거주를 하고 한국으로 되돌아온 157명의 귀국성인이었다. 위계적 회귀분석을 통해 재문화충격과 각각의 조절변인에 대해 이원상호작용을 분석한 결과, 재문화충격과 주관적 안녕감 간에는 부적인 관계가 있었으며, 가족지지의 조절효과만이 유의한 것으로 나타났다. 구체적으로, 재문화충격과 주관적 안녕감 간의 관계 강도는 가족지지가 높을 때 완화되는 것으로 나타났다. 다음으로 재문화충격, 사회적 지지 중 한 요인, 문화정체성 중 한 요인을 대상으로 삼원상호작용을 분석한 결과, 재문화충격, 가족지지, 모국정체성의 삼원상호작용이 유의하였다. 특히 재문화충격과 주관적 안녕감의 관계강도는 가족지지와 문화정체성 중 한가지만 낮을 때 보다 모두 다 낮을 때 더 높은 것으로 나타났다. 이러한 연구결과는 귀국성인들의 재문화충격과 주관적 안녕감의 관계가 조절가능하며 재문화적응과정에서의 가족지지(환경적 요인)와 모국정체성(개인내적 요인)의 중요성을 시사한다.

• 한국미생물·생명공학회지
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• 제35권3호
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• pp.177-183
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• 2007

열충격 시그마인자를 코딩하는 유전자 rpoH가 결여된 돌연변이체 대장균(Escherichia coli satrain A7448)을, 메탄올 자화세균인 Methylovorus sp. strain SS1 DSM11726의 phagemid library로 형질전환 시켜서 $30^{\circ}C$에서 성장하는 Escherichia coli strain A7448 로부터 Methylovorus sp. strain SS1 DSM11726의 rpoH 유전자를 클로닝하고 그 염기서열을 분석하였다. 1,793-bp 염기서열 분석 결과 Methylovorus sp. strain SS1 DSM11726의 RpoH는 284개의 아미노산으로 이루어져 있었으며 예상된 분자량은 32,006, p1값은 5.79로 나타났으며, 동일계열의 ${\beta}$-proteobacteria에 속하는 세균들의 RpoH와 높은 상동성을 보여주었다. Methylovorus sp. strain SS1 DSM11726의 RpoH는 대장균의 RpoH의 기능을 대신할 수 있음을 보여주었다. 열충격 후 RpoH양은 15분까지 지속적으로 증가하다 20분 뒤 양이 감소하는 양상을 나타내었다. 이는 Methylovorus sp. strain SS1 DSM11726의 RpoH 단백질 역시 열에 의해 유도됨을 말해 준다.