• International Journal of Naval Architecture and Ocean Engineering
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• 제10권2호
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• pp.180-187
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• 2018

Corrugated bulkhead has been adopted for cargo tank bulkheads of commercial vessels such as bulk carriers, product oil carriers and chemical tankers. It is considered that corrugated bulkhead is a preferred structural solution, compared to the flat stiffened bulkhead, due to several advantages such as lower mass, easier maintenance and smaller corrosion problems. Many researches to find the optimum shape of corrugated bulkhead have been mostly carried out for bulk carriers. Compared to corrugated bulkheads of bulk carriers, ones of chemical tankers are more complicated since they are composed of transverse and longitudinal bulkheads, and they are made of higher priced materials. The purpose of this study is the development of minimum weight design method for corrugated bulkhead of chemical tankers. Evolution strategy is applied as an optimization technique. It has been verified from many researches that evolution strategy searches global optimum point prominently by using multi-individual searching technique. Multi-individual searching methods need excessive time if they connect to 3-D finite element model for repetitive structural analyses. In order to resolve this issue, 2-D beam element connected to deck and lower stool is substituted for a corrugated structure in this study. To verify the reliability of the structural responses by idealized 2-D beam model, they have been compared with ones by 3-D finite element model. In this study, optimum design for corrugated bulkhead of 30 K chemical tanker has been carried out, and the results by developed optimum design program have been compared with design data of existing ship. It is found out that optimum design is about 9% lighter than one of existing ship.

• Clinical and Experimental Pediatrics
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• 제65권1호
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• pp.35-46
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• 2022

Background: The growing prevalence of overweight and/or obese children is an important public health problem in both developed and developing countries. Although the association of obesity between parents and their children is well known, its underlying mechanisms are not well established. Purpose: This meta-analysis examined parent-child (PC) relationships in obesity and identified factors such as world region and country income level that may influence this relationship. Methods: We identified all related studies published between January 1, 2015 and May 31, 2020 by conducting a literature search using the MeSH terms "obesity," "overweight," "body mass index," "parent," "child," "associate," and "relate" in the PubMed database in English. Results: The meta-analysis of 23 studies that reported an odds ratio (OR) for parent and child obesity associations found a significant association between parents and children who were overweight or obese (pooled OR, 1.97; 95% confidence interval, 1.85-2.10). A meta-regression analysis was used to examine the sources of interstudy heterogeneity. The association between parent and child obesity was higher in Asia than in Europe and the Middle East and higher in high-income countries than in middle-or low-income countries. In addition, a higher association between parent and child obesity was found when both parents were obese than when only the father or mother was obese. This study from multiple countries indicates a significant PC relationship in weight status that varies according to PC pair type, parent and child weight statuses, world region, and country income level. Conclusion: These results demonstrate that the risk of childhood obesity is greatly influenced by parental weight status and indicate that parents could play an important role in preventing child obesity.

• BMB Reports
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• 제55권12호
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• pp.633-638
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• 2022

Liver regeneration is a well-known systemic homeostatic phenomenon. The N⁶-methyladenosine (m⁶A) modification pathway has been associated with liver regeneration and hepatocellular carcinoma. m⁶A methyltransferases, such as methyltransferase 3 (METTL3) and methyltransferase 14 (METTL14), are involved in the hepatocyte-specific-regenerative pathway. To illustrate the role of METTL14, secreted from non-parenchymal liver cells, in the initiation phase of liver regeneration, we performed 70% partial hepatectomy (PH) in Mettl14 heterozygous (HET) and wild-type (WT) mice. Next, we analyzed the ratio of liver weight to body weight and the expression of mitogenic stimulators derived from non-parenchymal liver cells. Furthermore, we evaluated the expression of cell cycle-related genes and the hepatocyte proliferation rate via MKI67-immunostaining. During regeneration after PH, the weight ratio was lower in Mettl14 HET mice compared to WT mice. The expressions of hepatocyte growth factor (HGF) and tumor necrosis factor (TNF)-α, mitogens derived from non-parenchymal liver cells that stimulate the cell cycle, as well as the expressions of cyclin B1 and D1, which regulate the cell cycle, and the number of MKI67-positive cells, which indicate proliferative hepatocyte in the late G1-M phase, were significantly reduced in Mettl14 HET mice 72 h after PH. Our findings demonstrate that global Mettl14 mutation may interrupt the homeostasis of liver regeneration after an acute injury like PH by restraining certain mitogens, such as HGF and TNF-α, derived from sinusoidal endothelial cells, stellate cells, and Kupffer cells. These results provide new insights into the role of METTL14 in the clinical treatment strategies of liver disease.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제26권4호
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• pp.213-223
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• 2023

Purpose: Pediatric patients in low-income countries are at a high risk of malnutrition. Numerous screening tools have been developed to detect the risk of malnutrition, including the Subjective Global Nutritional Assessment (SGNA), Pediatric Yorkhill Malnutrition Score (PYMS), Screening Tool for the Assessment of Malnutrition in Pediatrics (STAMP), and Screening Tool for Risk of Nutritional Status and Growth (STRONGkids). However, anthropometry remains the main tool for assessing malnutrition. We aimed to identify the value of four nutritional screening tools versus anthropometry for evaluating the nutritional status of children. Methods: We conducted a cross-sectional study of 1,000 children aged 1-12 years who visited the outpatient clinic of Cairo University Pediatric Hospital. Each participant was evaluated using anthropometric measurements (weight, length/height, and weight for length/height) as well as the PYMS, STAMP, STRONGkids, and SGNA screening tools. The sensitivities and specificities of these four tools were assessed using anthropometry as the gold standard. Results: Of the patients, 1.7% were underweight, 10.2% were wasted, and 35% were stunted. STRONGkids demonstrated the highest sensitivity (79.4%) and a high specificity (80.2%) for detecting malnutrition compared with weight for height, followed by STAMP, which demonstrated lower sensitivity (73.5%) but higher specificity (81.4%). PYMS demonstrated the lowest sensitivity (66.7%) and the highest specificity (93.5%), whereas SAGA demonstrated higher sensitivity (77.5%) and lower specificity (85.4%) than PYMS. Conclusion: The use of nutritional screening tools to evaluate the nutritional status of children is valuable and recommended as a simple and rapid method for identifying the risk of malnutrition in pediatric patients.

• Anatomy and Cell Biology
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• 제56권1호
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• pp.122-136
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• 2023

Depression is a prevalent global problem since ages, predominately treated with SSRI. Cipralex, is an antidepressant of the SSRIs class used as a remedy for mood, depression and anxiety. Silymarin (SIL), a natural free radical scavenging, has an antioxidant and anti-inflammatory properties. This hypothesis evaluates, for the first time, the role of cipralex on the structure of the endocrine and exocrine components of the pancreas and assess the beneficial effects of SIL on these changes. Forty-five rats were divided into control, cipralex, and cipralex plus SIL groups. During sacrifice, all rats and pancreases were weighed and the ratio of pancreatic weight (PW) to rat weight (RW) was calculated, blood samples were collected to estimate fasting glucose, insulin and amylase levels, the specimens were prepared for histological, immunohistochemical (inducible nitric oxide synthase [iNOS], tumour necrosis factor-alpha [TNF-α], caspase 3, proliferating cell nuclear antigen [PCNA], and anti-insulin antibody), and morphometrical studies. Cipralex group exhibited marked destruction of the pancreatic architecture of the exocrine and endocrine parts, with a dense collagen fiber deposition. Also, there is highly significant decrease (P<0.001) of PW/RT ratio, insulin, and amylase levels, the number and diameter of islets of Langerhans, the number of PCNA positive immunoreactive cells, and the number of insulin positive β-cells. Furthermore, a highly significant increase of glucose level, iNOS, TNF-α, and caspase-3 positive immunoreactive cells in the islets of Langerhans and acinar cells were observed. SIL improves the pancreatic histological architecture, weight loss, biochemical, and immunohistochemical analyses. Administering SIL is advantageous in managing cipralex induced pancreatic injury via its anti-inflammatory, antioxidant, and anti-apoptotic qualities.

• 한국환경생태학회지
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• 제28권6호
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• pp.634-641
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• 2014

본 연구에서는 지구온난화 조건에서 한국의 주요 작물인 백태와 서목태의 식물계절, 잎 수, 원줄기의 마디 수, 가지 수, 식물개체당 총 종자 수와 총 꼬투리 수, 식물개체당 총 종자 무게, 꼬투리당 종자 수 그리고 종자 하나의 무게에 대한 반응을 알아보았다. 이를 위해 $CO_2$농도가 일반 대기조건과 같은 대조구와, $CO_2$농도와 온도를 상승시킨 처리구에서 두 종의 콩을 생육시켜 관찰하였다. $CO_2$농도는 540 ppm으로, 온도는 처리구가 대조구보다 $2.2^{\circ}C$ 상승하도록 설계하였다. 그 결과 백태의 최초 개엽시기, 서목태의 최초 개화시기와 열매성숙시기는 대조구보다 처리구에서 늦어졌다. 백태와 서목태의 잎, 가지 그리고 원줄기의 마디의 수는 대조구와 처리구간에 차이가 없었으나 서목태의 가지 수는 처리구에서 6월에만 적었다. 백태의 종자 하나당 무게와 꼬투리당 종자 수는 대조구와 처리구 간 차이가 없었으나, 식물개체당 총 꼬투리 수와 식물개체당 총 종자 수는 대조구보다 처리구에서 적었다. 그러나 식물개체당 총 종자무게는 대조구와 처리구 간에 차이가 없었다. 서목태의 종자 하나당 무게와 꼬투리당 종자 수는 대조구와 처리구 간 차이가 없었으나, 식물개체당 총 꼬투리 수는 대조구보다 처리구에서 적었다. 또, 식물개체당 총 종자 수는 대조구와 처리구간 차이가 없었으나, 식물개체당 총 종자 무게는 대조구보다 처리구에서 더 가벼웠다. 이상으로 볼 때, 지구온난화로 백태는 종자 수가 감소하고 서목태는 최초 개엽, 개화, 성숙시기, 그리고 가지 형성시기가 늦어지며, 그 결과 꼬투리 수와 종자 무게가 감소되어 생산량이 줄어들 것이다. 이러한 개체군의 생장을 연구하는 것은 지구온난화에 대한 육상식물의 생태적 반응 연구에 중요한 자료로 활용될 것이다.

• 전기학회논문지
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• 제62권11호
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• pp.1578-1583
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• 2013

In this paper, stochastic optimization algorithms of PSO (Particle Swarm Optimization) and APSO (Adaptive Particle Swam Optimization) are studied and compared. It is revealed that the APSO provides faster convergence and better search efficiency than the conventional PSO when they are adopted to find the global minimum of a two-dimensional function. The advantages of the APSO comes from the ability to control the inertia weight, and acceleration coefficients. To verify that the APSO is working better than the standard PSO, the design of a 10GHz microstrip patch as one of the elements of a high frequency array antenna is taken as a test-case and shows the optimized result with 5 iterations in the APSO and 28 iterations in th PSO.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.223-226
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• 1997

Usually, the Evolutionary Algorithms(EAs) are considered more efficient for optimal, system design because EAs can provide higher opportunity for obtaining the global optimal solution. This paper presents a mechanism of co-evolution consists of the two genetic algorithms(GAs). This mechanism includes host populations and parasite populations. These two populations are closely related to each other, and the parasite populations plays an important role of searching for useful schema in host populations. Host population represented by feedforward neural network and the result of co-evolution we will find the optimal structure of the neural network. We used the genetic algorithm that search the structure of the feedforward neural network, and evolution strategies which train the weight of neuron, and optimize the net structure. The validity and effectiveness of the proposed method is exemplified on the stabilization and position control of the inverted-pendulum system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권6호
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• pp.2627-2647
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• 2016

With the rapid growth of microblog, expert identification on microblog has been playing a crucial role in many applications. While most previous expert identification studies only assess global authoritativeness of a user, there is no way to differentiate the authoritativeness in a particular aspect of topics. In this paper, we propose a novel model, which jointly models text and following relationship in the same generative process. Furthermore, we integrate a similarity-based weight scheme into the model to address the popular bias problem, and use followee topic distribution as prior information to make user's topic distribution more precisely. Our empirical study on two large real-world datasets shows that our proposed model produces significantly higher quality results than the prior arts.

• 전기학회논문지
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• 제56권6호
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• pp.1055-1063
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• 2007

This paper introduces an optimal design technique for a 250-watt isolation transformer using an optimization method, dynamic encoding algorithm for searches (DEAS). Although the optimal design technique for transformers dates back to 1970s and various optimization methods have been developed so far, literature concerning global optimization for transformer core design is rarely found against its importance. In this paper, core configuration of the isolation transformer whose performance is computed by complex mathematical steps is optimized with DEAS. The optimization result confirms that DEAS can be successfully employed to transformer core design for various performance specifications only by adjusting weight factors in cost function.