• Biomolecules & Therapeutics
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• 제25권3호
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• pp.231-238
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• 2017

Myelin is a specialized structure of the nervous system that both enhances electrical conductance and insulates neurons from external risk factors. In the central nervous system, polarized oligodendrocytes form myelin by wrapping processes in a spiral pattern around neuronal axons through myelin-related gene regulation. Since these events occur at a distance from the cell body, post-transcriptional control of gene expression has strategic advantage to fine-tune the overall regulation of protein contents in situ. Therefore, many research interests have been focused to identify RNA binding proteins and their regulatory mechanism in myelinating compartments. Fragile X mental retardation protein (FMRP) is one such RNA binding protein, regulating its target expression by translational control. Although the majority of works on FMRP have been performed in neurons, it is also found in the developing or mature glial cells including oligodendrocytes, where its function is not well understood. Here, we will review evidences suggesting abnormal translational regulation of myelin proteins with accompanying white matter problem and neurological deficits in fragile X syndrome, which can have wider mechanistic and pathological implication in many other neurological and psychiatric disorders.

• 한국안전학회지
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• 제34권5호
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• pp.159-166
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• 2019

The seismic PSA is to probabilistically estimate the potential damage that a large earthquake will cause to a nuclear power plant. It integrates the probabilistic seismic hazard analysis, seismic fragility analysis, and system analysis and is utilized to identify seismic vulnerability and improve seismic capacity of nuclear power plants. Recently, the seismic risk of domestic multi-unit nuclear power plant sites has been evaluated after the Great East Japan Earthquake and Gyeongju Earthquake in Korea. However, while the currently available methods for system analysis can derive basic required results of seismic PSA, they do not provide the detailed results required for the efficient improvement of seismic capacity. Therefore, for in-depth seismic risk evaluation, improved system analysis method for seismic PSA has become necessary. This study develops a system analysis method that is not only suitable for multi-unit seismic PSA but also provides risk information for the seismic capacity improvements. It will also contribute to the enhancement of the safety of nuclear power plants by identifying the seismic vulnerability using the detailed results of seismic PSA. In addition, this system analysis method can be applied to other external event PSAs, such as fire PSA and tsunami PSA, which require similar analysis.

• Nuclear Engineering and Technology
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• 제51권5호
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• pp.1297-1306
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• 2019

Probabilistic safety assessments (PSA) have been used for several decades to visualize the risk level of commercial nuclear power plants (NPPs). Since the role of a human reliability analysis (HRA) is to provide human error probabilities for safety critical tasks to support PSA, PSA quality is strongly affected by HRA quality. Therefore, it is important to understand the underlying limitations or problems of HRA techniques. For this reason, this study conducted a survey among 14 subject matter experts who represent the HRA community of domestic Korean NPPs. As a result, five significant HRA issues were identified: (1) providing a technical basis for the K-HRA (Korean HRA) method, and developing dedicated HRA methods applicable to (2) diverse external events to support Level 1 PSA, (3) digital environments, (4) mobile equipment, and (5) severe accident management guideline tasks to support Level 2 PSA. In addition, an HRA method to support multi-unit PSA was emphasized because it plays an important role in the evaluation of site risk, which is one of the hottest current issues. It is believed that creating such a catalog of prioritized issues will be a good indication of research direction to improve HRA and therefore PSA quality.

• 교육시설 논문지
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• 제26권5호
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• pp.25-36
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• 2019

School gymnasium is a multi-purpose large space building for various events and physical education activities, and is a facility that requires an approach to the desirable structural design, besides mechanical problems of structure against loads. For the integrated structure design concerning the architectural features, the major considerations of gymnasium planning that are the internal and external shape of the gymnasium, the space scale with structure members, the structural efficiency by members weight reduction and openness of the gymnasium space will have to take into account in the structural planning. From this point of view, the several cases of the school gymnasium were investigated and the parametric analyses were performed to the models using the various structural system. The parameters were the composition elements of structure system that are profile of structure, rigidity of member, connection and anchorage and stability. At the result, It was presented that the profile of structure member was the most influential factor to structural efficiency and the effect of the form and space of gymnasium. Also the design informations of structure design having the various feature of form and space were presented for the initial gymnasium planning.

• Molecules and Cells
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• 제44권12호
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• pp.861-878
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• 2021

The human genome contains many retroviral elements called human endogenous retroviruses (HERVs), resulting from the integration of retroviruses throughout evolution. HERVs once were considered inactive junk because they are not replication-competent, primarily localized in the heterochromatin, and silenced by methylation. But HERVs are now clearly shown to actively regulate gene expression in various physiological and pathological conditions such as developmental processes, immune regulation, cancers, autoimmune diseases, and neurological disorders. Recent studies report that HERVs are activated in patients suffering from coronavirus disease 2019 (COVID-19), the current pandemic caused by SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) infection. In this review, we describe internal and external factors that influence HERV activities. We also present evidence showing the gene regulatory activity of HERV LTRs (long terminal repeats) in model organisms such as mice, rats, zebrafish, and invertebrate models of worms and flies. Finally, we discuss several molecular and cellular pathways involving various transcription factors and receptors, through which HERVs affect downstream cellular and physiological events such as epigenetic modifications, calcium influx, protein phosphorylation, and cytokine release. Understanding how HERVs participate in various physiological and pathological processes will help develop a strategy to generate effective therapeutic approaches targeting HERVs.

• Nuclear Engineering and Technology
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• 제54권4호
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• pp.1394-1405
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• 2022

The importance of ensuring the inherent safety and security has been more emphasized in recent years to demonstrate the integrity of nuclear facilities under external human-induced events (e.g. aircraft crashes). This work suggests a simulation methodology to effectively evaluate the impact of a commercial aircraft engine onto a dry storage facility. A full-scale engine model was developed and verified by Riera force-time history analysis. A reinforced concrete (RC) structure of a dry storage facility was also developed and material behavior of concrete was incorporated using three constitutive models namely: Continuous Surface Cap, Winfrith, and Karagozian & Case for comparison. Strain-based erosion limits for concrete were suitably defined and the local responses were then compared and analyzed with empirical formulas according to variations in impact velocity. The proposed methodology reasonably predicted such local damage modes of RC structure from the engine missile, and the analysis results agreed well with the calculations of empirical formulas. This research is expected to be helpful in reviewing the dry storage facility design and in the probabilistic risk assessment considering diverse impact scenarios.

• Asia Marketing Journal
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• 제14권3호
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• pp.153-167
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• 2012

KB Kookmin Card has separated as an independent corporation from KB Kookmin Bank Credit Card Business Group on March, 2011. Ever since, KB Kookmin Card worked to build its own brand identity. The strategic preparation and conscientious implementations made KB Kookmin Card position in consumer's mind with a strong and unique brand image. Its new brand image was rooted in the inherited strengths of reliable and sincere image. However, it faced the challenge to compete in credit card industry in which most competitors had an advanced and sophisticated image. The strengths of KB Kookmin Card were also at the same time their limitations. KB Kookmin Card took a strategy that strengthened the strengths and improved the weaknesses. It focused on the core competence of being a people's sincere life supporter that helps people make savings from everyday events to make a good sum rather than being a lump sum benefit. The brand introduction strategy was implemented in 2011. The implementation focused on the activities that made internal as well as external customers be aware of the brand. Communication programs using a variety of media were executed to attain this goal. In 2012, second phase communication programs were introduced to elaborate the newly established brand image. It introduced many extended products as well as accessory programs which targeted the segments. Also, various CSR activities in many social domains helped consumers and the public to consider KB Kookmin Card an authentic, caring, trustworthy, and consistently-developing supporter in their everyday lives.

• 무역학회지
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• 제47권2호
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• pp.133-154
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• 2022

The Baltic Capesize Index (BCI), which is used as an indicator for marine transportation of steel raw materials, is one of the key economic indexes for managing the risk of loss due to rapid market fluctuations when steel companies establish business strategies and procuring plans for raw materials. Still, the conditions of supply and demand of steel raw materials has been extremely affected by volatility shocks from drastic events like the financial crisis such as the Lehman Brothers incident and changes in the external environment such as COVID-19. And, especially since the 2008 financial crisis, endeavors to predict the market conditions of the steel raw material is becoming more and more arduous for the deepening uncertainty and increased volatility of BCI, which has been used as a leading indicator of the real economy. This study investigates the correlation between the steel raw material market and the marine transportation market by estimating the spillover effect of information between markets. The vector error correction model (VECM) was used to analyze information transfer based on the correlation between the BCI and crude steel production, capesize fleet supply, raw material price, and cargo volume.

• 한국발생생물학회지:발생과생식
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• 제12권2호
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• pp.117-124
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• 2008

지구상의 모든 생명체들은 자신의 생존과 종의 영속성을 보장하기 위해 우호적이지 않은 환경 변화에 대응하기 위한 효과적인 전략을 발전시켜왔다. 그 결과, 생명체들은 환경요인들의 변화에도 불구하고 체내 생리적 환경의 역동적인 평형, 즉 항상성(homeostasis)을 유지해 나간다. 스트레스는 항상성을 위협하는 정서적 그리고 물리적 반응이다. 스트레스는 일시적일 뿐만 아니라 거의 영구적인 영향을 개체에 줄 수 있는데, 특히 출생전 스트레스는 유전 코드의 변경없이 성체의 기능과 구조를 바꿀 수 있는 '후생학적 프로그래밍'을 할 수 있음이 최근의 연구들에 의해 알려졌다. 본 논문에서는 출생 전 스트레스를 받은 수컷 흰쥐에서 나타나는 생식과 연관된 일련의 사건들, 예를 들어 성적 이형현상을 보이는 뇌 지역의 변화, 신경전달물질 대사의 수정, 생식내분비 상태의 변화, 그리고 마지막으로 성행동의 이상들을 소개한다. 태아의 뇌는 출생전 프로그래밍에 극히 민감한데, 특히 글루코코티코이드는 강력한 뇌-프로그래밍 능력을 갖고 있다. 모체 스트레스에 의해 유도된 글루코코티코이드 입력에 의한 태아 뇌의 지속적인 과도 활성은 신경 가소성을 증가시키는 새로운 프로그램을 제공할 것이다. 그리고 증가한 신경 가소성은 환경 도전 속에서 개체가 더 잘 적응하도록 하는 증가된 표현형의 가소성에 대한 기초가 될 것이다. 결론적으로, '혹독한' 환경을 태아기에 경험한 개체는 미래에 자신의 생존 가능성을 높이기 위해 번식능력을 일부 포기하도록 후생학적으로 (재)프로그램하는 것으로 추정된다.

• 생명과학회지
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• 제26권3호
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• pp.364-375
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• 2016

번역 후 변형 과정은 외부 자극으로부터 세포의 신속한 반응을 야기하는데 있어서 매우 효율적인 기작이다. 이 중, 유비퀴티네이션은 진핵생물 내 대표적인 번역 후 변형 과정으로서, 이러한 유비퀴티네이션에 의해 매개되는 UPS (유비퀴틴/프로테아좀 시스템)는 세포 내 다양한 단백질들의 분해과정을 통해 그들의 안정성을 조절한다. 유비퀴티네이션 과정에 참여하는 3종류의 효소 중에서, E3 효소는 분해할 대상 기질을 결정한다는 면에서 그 중요성을 가지고 있다. CRL (cullin-RING E3 ubiquitin ligase)은 E3 효소 중 가장 거대한 그룹을 형성하고 있는데, 이들은 생체 내에서 cullin, RBX1, 어댑터, 기질 수용체로 이루어진 복합체의 형태로서 그 기능을 발휘한다. 이 중, SCF 복합체로도 알려진 CRL1 복합체의 기능은 다양한 연구를 통해 광범위하게 알려져 온 반면, CRL4 복합체에 대한 연구 및 고찰은 상대적으로 미흡한 실정이다. 또한, 애기장대는 DCAF로 명명된 잠재적 기질 수용체를 총 119개 보유하고 있는데, 현재까지 이들 중 일부 기질 수용체들의 기능만이 밝혀진 상태로서, 나머지 기질 수용체들의 기능 규명은 향후 활발히 탐색되어야 할 연구분야라 할 수 있다. 본 총설에서는 식물의 CRL4 복합체의 구조 및 활성 조절을 알아보고, 각 CRL4 복합체가 관여하는 다양한 식물 내 이벤트에 관하여 최근까지 보고된 CRL4 기질 수용체들을 중심으로 그 연구 진행 사항을 업데이트하고자 한다. 이러한 접근은 각 CRL4 복합체가 기능하는 식물의 다양한 신호 전달 기작들을 보다 명확히 이해하고, 향후 전체 CRL4 복합체의 작용 네트워크를 구축하는데 있어 도움이 될 것으로 사료된다.