• Journal of Welding and Joining
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• 제32권1호
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• pp.93-101
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• 2014

This study aims to investigate the effect of heat input of outside SAW weld on low temperature toughness($-20^{\circ}C$) of inside SAW weld for API 5L X70 with sour gas resistance. As increasing heat input of the outside weld, low temperature toughness of the inside weld was decreased. Especially, in spite of the same heat input, the value of low temperature toughness was fluctuated. On the basis of fracture and microstructure analysis, the low temperature toughness is correlated with the fracture area ratio of shear lips and four kinds of fracture sections. These sections were divided with size and shape of dimple correlated with grain boundary ferrite and cleavage correlated acicular and polygonal ferrite in grain. Therefore, it was seen that these sections were two of final solidification area in the inside weld and the outside weld, no reheated zone and reheated zone in the inside weld. In conclusion, it is thought that the difference of low temperature toughness at the same heat input is due to the fact that each of impact test specimens could have the different microstructure, even though the notch was machined under the error tolerance of 1mm. It is because the final solidification area of the inside weld is very narrow.

• Design & Manufacturing
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• 제14권3호
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• pp.23-30
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• 2020

Laser Assisted Thermo-Compression Bonding (LATCB) has been proposed to improve the "chip tilt due to the difference in solder bump height" that occurs during the conventional semiconductor chip bonding process. The bonding module of the LATCB system has used a piezoelectric actuator to control the inclination of the compression jig on a micro scale, and the piezoelectric actuator has been directly coupled to the compression jig to minimize the assembly tolerance of the compression jig. However, this structure generates a lateral force in the piezoelectric actuator when the compression jig is tilted, and the stacked piezoelectric element vulnerable to the lateral force has a risk of failure. In this paper, the optimal design of the flexure hinge was performed to minimize the lateral force generated in the piezoelectric actuator when the compression jig is tilted by using the displacement difference of the piezoelectric actuator in the bonding module for LATCB. The design variables of the flexure hinge were defined as the hinge height, the minimum diameter, and the notch radius. And the effect of the change of each variable on the stress generated in the flexible hinge and the lateral force acting on the piezoelectric actuator was analyzed. Also, optimization was carried out using commercial structural analysis software. As a result, when the displacement difference between the piezoelectric actuators is the maximum (90um), the maximum stress generated in the flexible hinge is 11.5% of the elastic limit of the hinge material, and the lateral force acting on the piezoelectric actuator is less than 1N.

• International Journal of Contents
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• 제7권2호
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• pp.26-31
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• 2011

People with obesity or over-weight need nutritional intervention to reduce their weight, because weight loss reduces the incidence rate of chronic diseases such as hypertension, type II diabetes, cardiovascular diseases and cancer in obese people. This study was to develop a system for individualized weight control program available both for wired and wireless internet users. This system is especially useful to users carrying wireless internet mobile device. If they input their physical information (height, weight and waist circumference) and mineral levels measured by hair tissue mineral analysis, the system provides evaluation of their health status and metabolic related functions such as endocrine and carbohydrate tolerance. Based on these evaluations, food menus are then offered to them to manage their health status and to improve their metabolic related physiological functions in a personalized way. The system also provides more information for recommended foods, such as nutritional information, food ingredients, recipes, and videos related to cooking. Bibimbap was selected as an example dish for customized contents for mobile web. Bibimbap is one of the most well-known Korean traditional dishes prepared with various kinds of ingredients including several different kinds of vegetables, meat, and egg so that it is a low calorie dish as well as a well-balanced diet. Therefore, this system developed in this study allows the mobile users to access web site through wired wireless internet everywhere and provides a customized content to the users to manage their weight and finally to achieve a desirable weight.

• Journal of Microbiology and Biotechnology
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• 제26권2호
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• pp.315-325
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• 2016

A novel esterase gene, est7K, was isolated from a compost metagenomic library. The gene encoded a protein of 411 amino acids and the molecular mass of the Est7K was estimated to be 44,969 Da with no signal peptide. Est7K showed the highest identity of 57% to EstA3, which is an esterase from a drinking water metagenome, when compared with the enzymes with reported properties. Est7K had three motifs, SMTK, YSV, and WGG, which correspond to the typical motifs of family VIII esterases, SxxK, Yxx, and WGG, respectively. Est7K did not have the GxSxG motif in most lipolytic enzymes. Three additional motifs, LxxxPGxxW, PLGMxDTxF, and GGxG, were found to be conserved in family VIII enzymes. The results of the phylogenetic analysis and the alignment study suggest that family VIII enzymes could be classified into two subfamilies, VIII.1 and VIII.2. The purified Est7K was optimally active at 40ºC and pH 10.0. It was activated to exhibit a 2.1-fold higher activity by the presence of 30% methanol. It preferred short-length p-nitrophenyl esters, particularly p-nitrophenyl butyrate, and efficiently hydrolyzed glyceryl tributyrate. It did not hydrolyze β-lactamase substrates, tertiary alcohol esters, glyceryl trioleate, fish oil, and olive oil. Est7K preferred an S-enantiomer, such as (S)-methyl-3-hydroxy-2-methylpropionate, as the substrate. The tolerance to methanol and the substrate specificity may provide potential advantage in the use of the enzyme in pharmaceutical and other biotechnological processes.

• Journal of Microbiology and Biotechnology
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• 제22권5호
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• pp.575-584
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• 2012

Listeria monocytogenes is an important foodborne pathogen that comprises four genetic lineages: I, II, III, and IV. Of these, lineage II is frequently recovered from foods and environments and responsible for the increasing incidence of human listeriosis. In this study, the phylogenetic structure of lineage II was determined through sequencing analysis of the ascB-dapE internalin cluster. Fifteen sequence types proposed by multilocus sequence typing based on nine housekeeping genes were grouped into three distinct sublineages, IIA, IIB, and IIC. Organization of the ascB-dapE internalin cluster could serve as a molecular marker for these sublineages, with inlGHE, inlGC2DE, and inlC2DE for IIA, IIB, and IIC, respectively. These sublineages displayed specific genetic and phenotypic characteristics. IIA and IIC showed a higher frequency of recombination (${\rho}/{\theta}$). However, recombination events had greater effect (r/m) on IIB, leading to its high nucleotide diversity. Moreover, IIA and IIB harbored a wider range of internalin and stress-response genes, and possessed higher nisin tolerance, whereas IIC contained the largest portion of low-virulent strains owing to premature stop codons in inlA. The results of this study indicate that IIA, IIB, and IIC might occupy different ecological niches, and IIB might have a better adaptation to a broad range of environmental niches.

• 한국정보과학회논문지:소프트웨어및응용
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• 제28권12호
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• pp.896-909
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• 2001

현재 새롭게 개발되는 소프트웨어는 50% 이상이 분산 플랫폼에서 개발되고 있다. 또한 분산 컴포넌트 기반의 소프트웨어 개발을 가능하게 하는 EJB(Enterprise Java Beans)[1] COM(Component Object Model )[2]. CORBA(Common Object Request Broker Architecture)[3] 와 같은 기술이 급격히 발전하고 있다. 따라서 분산 플랫폼 상에서 컴포넌트 기반의 응용 소프트웨어 개발을 위한 체계적인 개발 프로세스가 요구된다. 그러나 현재의 일반적인 컴포넌트 기반 소프트웨어 개발 방법론은 각 작업들간의 관 계와 각 작업의 산출물간의 관계를 명확히 제시하지 않는다. 또한 분산 응용 소프트웨어 개발에 있어서 고려되어야 할 분산 이슈에 대해서도 체계적으로 다루지 않고 있다. 본 논문에서는 분산 컴포넌트 기반의 응용 소프트웨어 개발을 위한 분석 및 설계 방법을 제시한다. 본 논문에서 제시하는 방법에서는 UMI 기반의 프로세스인 Unified process를 바탕으로 하여 체계적인 개발 지침과 산출물의 관계를 제시한다 또한 플랫폼과 프로그래밍 언어에 독립적인 CORBA 환경을 고려하여 성능. 결함 방지, 안전성, 분산 트랜잭션의 분산 이슈를 명시적으로 다루는 지침을 제시한다.

• 한국산림과학회지
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• 제78권3호
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• pp.302-313
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• 1989

관악산(冠岳山) 암석산지(岩石山地)에서 지표화(地表火)가 발생(發生)한지 5년(年)이 경과(經過)한 후(後) 토양조건(土壤條件) 및 삼림식생(森林植生) 변화(變化)에 미친 영향(影響)을 밝히고자 1988년(年) 7월(月)에 실시(實施)한 조사결과(調査結果)는 다음과 같다. 유기물함량(有機物含量), pH, 전질소함량(全窒素含量)은 산불발생(發生) 후(後) 3년(年)까지는 증가(增加)를 나타낸 후(後) 안정(安定)을 보였다. 5년간(年間) 초본(草本), 목본식물(木本植物)의 상대우점치(相對優占値) 변동(變動)에 의하여 출현종(出現種)들을 산불에 민감종(敏感種), 내성종(耐性種), 수입종(侵入種), 무반응종(無反應種)으로 구분(區分)할 수 있었다. 종다양도지수(種多樣度指數), 유사도지수(類似度指數) 등(等) 다양성지수(多樣性指數)의 변동(變動)을 고려(考慮)할 때, 산불 후(後) 5년(年)동안에 종구성측면(種構成側面)의 회복(回復)은 이루어 졌으나 수관울한(樹冠鬱閑), 임목성장(林木成長) 등(等) 식생발달측면(植生發達側面)에서의 회복(回復)은 아직 이루어지지 않은 것으로 판단(判斷)된다.

• 디지털융복합연구
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• 제18권1호
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• pp.199-209
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• 2020

본 연구의 목적은 조현병 자녀를 돌보는 어머니들의 감사경험의 본질을 탐색하고자 하였다. 서울시 일개 정신건강복지센터에 등록된 회원 중 조현병 진단 후 만 5년이 경과된 회원의 어머니 5명을 대상으로 심층면담을 하고, Giorgi(1997)의 현상학적 연구방법으로 분석하였다. 결과 조현병 자녀 어머니의 감사경험은 18개의 하위구성요소와 감사할 것 없이 척박한 땅에 떨어진 씨앗 같은 나, 새싹처럼 움트기 시작하는 감사, 포용을 통해 나무로 자란 감사, 자족과 바람의 열매를 맺는 감사, 베풂으로 인해 더 풍성해진 감사의 5가지 구성요소가 도출되고, 역동적 순환체계로 진행되어감을 확인하였다. 이로서 조현병 자녀 어머니의 감사경험은 원망, 수용, 용서, 소망, 나눔의 순방향으로 진행되기 위해서 정신건강전문가들의 적극적인 상담과 조현병 자녀 어머니들의 개별 또는 집단교육 및 중재프로그램 개발 연구가 더욱 확대되어야 한다.

• IMMUNE NETWORK
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• 제11권1호
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• pp.59-67
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• 2011

Background: Insulin resistance is an integral feature of metabolic syndromes, including obesity, hyperglycemia, and hyperlipidemia. In this study, we evaluated whether the aloe component could reduce obesity-induced inflammation and the occurrence of metabolic disorders such as blood glucose and insulin resistance. Methods: Male C57BL/6 obese mice fed a high-fat diet for 54 days received a supplement of aloe formula (PAG, ALS, Aloe QDM, and Aloe QDM complex) or pioglitazone (PGZ) and were compared with unsupplemented controls (high-fat diet; HFD) or mice fed a regular diet (RD). RT-PCR and western blot analysis were used to quantify the expression of obesity-induced inflammation. Results: Aloe QDM lowered fasting blood glucose and plasma insulin compared with HFD. Obesity-induced inflammatory cytokine (IL-$1{\beta}$, -6, -12, TNF-${\alpha}$) and chemokine (CX3CL1, CCL5) mRNA and protein were decreased markedly, as was macrophage infiltration and hepatic triglycerides by Aloe QDM. At the same time, Aloe QDM decreased the mRNA and protein of $PPAR{\gamma}/LXR{\alpha}$ and $11{\beta}$-HSD1 both in the liver and WAT. Conclusion: Dietary aloe formula reduces obesity-induced glucose tolerance not only by suppressing inflammatory responses but also by inducing anti-inflammatory cytokines in the WAT and liver, both of which are important peripheral tissues affecting insulin resistance. The effect of Aloe QDM complex in the WAT and liver are related to its dual action on $PPAR{\gamma}$ and $11{\beta}$-HSD1 ression and its use as a nutritional intervention against T2D and obesity-related inflammation is suggested.

• Journal of Ecology and Environment
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• 제43권4호
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• pp.364-375
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• 2019

Background: Ecologists continue to investigate the factors that potentially affect the pattern and magnitude of tree damage during catastrophic windstorms in forests. However, there still is a paucity of research on which trees are more vulnerable to direct damage by winds rather than being knocked down by the fall of another tree. We evaluated this question in a mixed hardwood-softwood forest within the Big Thicket National Preserve (BTNP) of southeast Texas, USA, which was substantially impacted by Hurricane Rita in September 2005. Results: We showed that multiple factors, including tree height, shade-tolerance, height-to-diameter ratio, and neighborhood density (i.e., pre-Rita stem distribution) significantly explained the susceptibility of trees to direct storm damage. We also found that no single factor had pervasive importance over the others and, instead, that all factors were tightly intertwined in a complex way, such that they often complemented each other, and that they contributed simultaneously to the overall susceptibility to and patterns of windstorm damage in the BTNP. Conclusions: Directly damaged trees greatly influence the forest by causing secondary damage to other trees. We propose that directly and indirectly damaged (or susceptible) trees should be considered separately when assessing or predicting the impact of windstorms on a forest ecosystem; to better predict the pathways of community structure reorganization and guide forest management and conservation practices. Forest managers are recommended to adopt a holistic view that considers and combines various components of the forest ecosystem when establishing strategies for mitigating the impact of catastrophic winds.