• Title/Summary/Keyword: influence functions method

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Domain decomposition technique to simulate crack in nonlinear analysis of initially imperfect laminates

  • Ghannadpour, S. Amir M.;Karimi, Mona
    • Structural Engineering and Mechanics
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    • v.68 no.5
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    • pp.603-619
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    • 2018
  • In this research, an effective computational technique is carried out for nonlinear and post-buckling analyses of cracked imperfect composite plates. The laminated plates are assumed to be moderately thick so that the analysis can be carried out based on the first-order shear deformation theory. Geometric non-linearity is introduced in the way of von-Karman assumptions for the strain-displacement equations. The Ritz technique is applied using Legendre polynomials for the primary variable approximations. The crack is modeled by partitioning the entire domain of the plates into several sub-plates and therefore the plate decomposition technique is implemented in this research. The penalty technique is used for imposing the interface continuity between the sub-plates. Different out-of-plane essential boundary conditions such as clamp, simply support or free conditions will be assumed in this research by defining the relevant displacement functions. For in-plane boundary conditions, lateral expansions of the unloaded edges are completely free while the loaded edges are assumed to move straight but restricted to move laterally. With the formulation presented here, the plates can be subjected to biaxial compressive loads, therefore a sensitivity analysis is performed with respect to the applied load direction, along the parallel or perpendicular to the crack axis. The integrals of potential energy are numerically computed using Gauss-Lobatto quadrature formulas to get adequate accuracy. Then, the obtained non-linear system of equations is solved by the Newton-Raphson method. Finally, the results are presented to show the influence of crack length, various locations of crack, load direction, boundary conditions and different values of initial imperfection on nonlinear and post-buckling behavior of laminates.

Warping and porosity effects on the mechanical response of FG-Beams on non-homogeneous foundations via a Quasi-3D HSDT

  • Mokhtar Nebab;Hassen Ait Atmane;Riadh Bennai;Mouloud Dahmane
    • Structural Engineering and Mechanics
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    • v.90 no.1
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    • pp.83-96
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    • 2024
  • This paper suggests an analytical approach to investigate the free vibration and stability of functionally graded (FG) beams with both perfect and imperfect characteristics using a quasi-3D higher-order shear deformation theory (HSDT) with stretching effect. The study specifically focuses on FG beams resting on variable elastic foundations. In contrast to other shear deformation theories, this particular theory employs only four unknown functions instead of five. Moreover, this theory satisfies the boundary conditions of zero tension on the beam surfaces and facilitates hyperbolic distributions of transverse shear stresses without the necessity of shear correction factors. The elastic medium in consideration assumes the presence of two parameters, specifically Winkler-Pasternak foundations. The Winkler parameter exhibits variable variations in the longitudinal direction, including linear, parabolic, sinusoidal, cosine, exponential, and uniform, while the Pasternak parameter remains constant. The effective material characteristics of the functionally graded (FG) beam are assumed to follow a straightforward power-law distribution along the thickness direction. Additionally, the investigation of porosity includes the consideration of four different types of porosity distribution patterns, allowing for a comprehensive examination of its influence on the behavior of the beam. Using the virtual work principle, equations of motion are derived and solved analytically using Navier's method for simply supported FG beams. The accuracy is verified through comparisons with literature results. Parametric studies explore the impact of different parameters on free vibration and buckling behavior, demonstrating the theory's correctness and simplicity.

Classification of Gene Data Using Membership Function and Neural Network (소속 함수와 유전자 정보의 신경망을 이용한 유전자 타입의 분류)

  • Yeom, Hae-Young;Kim, Jae-Hyup;Moon, Young-Shik
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.42 no.4 s.304
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    • pp.33-42
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    • 2005
  • This paper proposes a classification method for gene expression data, using membership function and neural network. The gene expression is a process to produce mRNA and protains which generate a living body, and the gene expression data is important to find out the functions and correlations of genes. Such gene expression data can be obtained from DNA 칩 massively and quickly. However, thousands of gene expression data may not be useful until it is well organized. Therefore a classification method is necessary to find the characteristics of gene data acquired from the gene expression. In the proposed method, a set of gene data is extracted according to the fisher's criterion, because we assume that selected gene data is the well-classified data sample. However, the selected gene data does not guarantee well-classified data sample and we calculate feature values using membership function to reduce the influence of outliers in gene data. Feature vectors estimated from the selected feature values are used to train back propagation neural network. The experimental results show that the clustering performance of the proposed method has been improved compared to other existing methods in various gene expression data.

The Quality of Life of Skin Disease Patients, Particularly Acne Patients (여드름을 중심으로 한 피부질환 환자의 삶의 질)

  • Byun, Hak-Sung;Um, Yu-Sik;Hur, Inn-Hee;Sim, Sung-Yong;Kim, Kyung-Jin
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.19 no.1
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    • pp.65-78
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    • 2006
  • Background : Quality of life(Qol) is a broad concept that incorporates all aspects of an individual's existence. There is many study about Qol of the patient with dermatic disease in the west, but in korea there is few study, particularly for oriental medical academic world. Objective : The purpose of this study is to Investigate the influence of dermatic disease, particularly acne on the Qol by using the korean version of skindex-29. Method : We measured the Qol of Kyungwon university student participating in Dongseo health examination by using the Korean version of Skindex-29. A total of 535 students were enrolled In this study. Results are reported as 3 scales scores (functions, emotions, and symptoms) and a composite score (average scale score). Result : 1) There were no statistically significant gender-related differences in Qol scores in patient group with acne. 2) There were no significant correlation between Age Duration and Qol socres in patient group with acne. 3) Acne group marked higher Qol scores than contact dermatitis and normal group (lower than Acne with atopic dermatitis group) within emotional scales. 4) Acne group marked higher Qol scores than scar, tinea cruris, and normal group (lower than Acne with atopic dermatitis group) within functional and total scales. 5) Acne group marked higher Qol scores than tinea cruris and normal group (lower than Atopic dermatitis group) within symptom scales. 6) In acne group that feel the necessity of medical treatment, group that be treated by occidental medical method marked lower Qol scores than group that don't be treated within functional, symptom, and total scales. 7) In acne group that don't be treated, group that feel the necessity of medical treatment marked higher Qol scores than group that don't feel within emotional, functional, and total scales. 8) Acne group that don't fee the necessity of medical treatment and be treated marked high scores than normal group within all scales. Conclusion : Acne is sometimes thought of as unimportant, but Acne significantly affects patient's Qol. Occidental medical treatment can help Acne patients to improve Qol. Even if someone who suffering from acne feel that he don't need to be treated, he had lower Qol than healthy controls. And we can expect that proper occidental medical treatment help him. But few study have discuss whether oriental medical method can improve Qol of acne patients. From now on we expect interesting study that measure effect of oriental medical therapy on Qol of Acne patients and compare with occidental medical therapy by using Qol mesure instrument.

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The Influence of Store Environment on Service Brand Personality and Repurchase Intention (점포의 물리적 환경이 서비스 브랜드 개성과 재구매의도에 미치는 영향)

  • Kim, Hyoung-Gil;Kim, Jung-Hee;Kim, Youn-Jeong
    • Journal of Global Scholars of Marketing Science
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    • v.17 no.4
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    • pp.141-173
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    • 2007
  • The study examines how the environmental factors of store influence service brand personality and repurchase intention in the service environment. The service industry has been experiencing the intensified competition with the industry's continuous growth and the influence from rapid technological advancement. Under the circumstances, it has become ever more important for the brand competitiveness to be distinctively recognized against competition. A brand needs to be distinguished and differentiated from competing companies because they are all engaged in the similar environment of the service industry. The differentiation of brand achievement has become increasingly important to highlight certain brand functions to include emotional, self-expressive, and symbolic functions since the importance of such functions has been further emphasized in promoting consumption activities. That is the recent role of brand personality that has been emphasized in the service industry. In other words, customers now freely and actively express their personalities or egos in consumption activities, taking an important role in construction of a brand asset. Hence, the study suggests that it is necessary to disperse the recognition and acknowledgement that the maintenance of the existing customers contributes more to boost repurchase intention when it is compared to the efforts to create new customers, particularly in the service industry. Meanwhile, the store itself can offer a unique environment that may influence the consumer's purchase decision. Consumers interact with store environments in the process of,virtually, all household purchase they make (Sarel 1981). Thus, store environments may encourage customers to purchase. The roles that store environments play are to provide informational cues to customers about the store and goods and communicate messages to stimulate consumers' emotions. The store environments differentiate the store from competing stores and build a unique service brand personality. However, the existing studies related to brand in the service industry mostly concentrated on the relationship between the quality of service and customer satisfaction, and they are mostly generalized while the connective studies focused on brand personality. Such approaches show limitations and are insufficient to investigate on the relationship between store environment and brand personality in the service industry. Accordingly, the study intends to identify the level of contribution to the establishment of brand personality made by the store's physical environments that influence on the specific brand characteristics depending on the type of service. The study also intends to identify what kind of relationships with brand personality exists with brand personality while being influenced by store environments. In addition, the study intends to make meaningful suggestions to better direct marketing efforts by identifying whether a brand personality makes a positive influence to induce an intention for repurchase. For this study, the service industry is classified into four categories based on to the characteristics of service: experimental-emotional service, emotional -credible service, credible-functional service, and functional-experimental service. The type of business with the most frequent customer contact is determined for each service type and the enterprise with the highest brand value in each service sector based on the report made by the Korea Management Association. They are designated as the representative of each category. The selected representatives are a fast-food store (experimental-emotional service), a cinema house (emotional-credible service), a bank (credible-functional service), and discount store (functional-experimental service). The survey was conducted for the four selected brands to represent each service category among consumers who are experienced users of the designated stores in Seoul Metropolitan City and Gyeonggi province via written questionnaires in order to verify the suggested assumptions in the study. In particular, the survey adopted 15 scales, which represent each characteristic factor, among the 42 unique characteristics developed by Jennifer Aaker(1997) to assess the brand personality of each service brand. SPSS for Windows Release 12.0 and LISREL were used in the analysis of data verification. The methodology of the structural equation model was used for the study and the pivotal findings are as follows. 1) The environmental factors ware classified as design factors, ambient factors, and social factors. Therefore, the validity of measurement scale of Baker et al. (1994) was proved. 2) The service brand personalities were subdivided as sincerity, excitement, competence, sophistication, and ruggedness, which makes the use of the brand personality scales by Jennifer Aaker(1997) appropriate in the service industry as well. 3) One-way ANOVA analysis on the scales of store environment and service brand personality showed that there exist statistically significant differences in each service category. For example, the social factors were highest in discount stores, while the ambient factors and design factors were highest in fast-food stores. The discount stores were highest in the sincerity and excitement, while the highest point for banks was in the competence and ruggedness, and the highest point for fast-food stores was in the sophistication, The consumers will make a different respond to the physical environment of stores and service brand personality that are inherent to the corresponding service interface. Hence, the customers will make a different decision-making when dealing with different service categories. In this aspect, the relationships of variables in the proposed hypothesis appear to work in a different way depending on the exposed service category. 4) The store environment factors influenced on service brand personalities differently by category of service. The factors of store's physical environment are transferred to a brand and were verified to strengthen service brand personalities. In particular, the level of influence on the service brand personality by physical environment differs depending on service category or dimension, which indicates that there is a need to apply a different style of management to a different service category or dimension. It signifies that there needs to be a brand strategy established in order to positively influence the relationship with consumers by utilizing an appropriate brand personality factor depending on different characteristics by service category or dimension. 5) The service brand personalities influenced on the repurchase intention. Especially, the largest influence was made in the sophistication dimension of service brand personality scale; the unique and characteristically appropriate arrangement of physical environment will make customers stay in the service environment for a long time and will lead to give a positive influence on the repurchase intention. 6) The store environment factors influenced on the repurchase intention. Particularly, the largest influence was made on the social factors of store environment. The most intriguing finding is that the service factor among all other environment factors gives the biggest influence to the repurchase intention in most of all service types except fast-food stores. Such result indicates that the customers pay attention to how much the employees try to provide a quality service when they make an evaluation on the service brand. At the same time, it also indicates that the personal factor is directly transmitted to the construction of brand personality. The employees' attitude and behavior are the determinants to establish a service brand personality in the process of enhancing service interface. Hence, there should be a reinforced search for a method to efficiently manage the service staff who has a direct contact with customers in order to make an affirmative improvement of the customers' brand evaluation at the service interface. The findings suggest several managerial implications. 1) Results from the empirical study indicated that store environment factors have a strong positive impact on a service brand personality. To increase customers' repurchase intention of a service brand, the management is required to effectively manage store environment factors and create a friendly brand personality based on the corresponding service environment. 2) Mangers and researchers must understand and recognize that the store environment elements are important marketing tools, and that brand personality influences on consumers' repurchase intention. Based on such result of the study, a service brand could be utilized as an efficient measure to achieve a differentiation by enforcing the elements that are most influential among all other store environments for each service category. Therefore, brand personality established involving various store environments will further reinforce the relationship with customers through the elevated brand identification of which utilization to induce repurchase decision can be used as an entry barrier. 3) The study identified the store environment as a component of service brand personality for the store's effective communication with consumers. For this, all communication channels should be maintained with consistency and an integrated marketing communication should be executed to efficiently approach to a larger number of customers. Mangers and researchers must find strategies for aligning decisions about store environment elements with the retailers' marketing and store personality objectives. All ambient, design, and social factors need to be orchestrated so that consumers can take an appropriate store personality. In this study, the induced results from the previous studies were extended to the service industry so as to identify the customers' decision making process that leads to repurchase intention and a result similar to those of the previous studies. The findings suggested several theoretical and managerial implications. However, the situation that only one service brand served as the subject of analysis for each service category, and the situation that correlations among store environment elements were not identified, as well as the problem of representation in selection of samples should be considered and supplemented in the future when further studies are conducted. In addition, various antecedents and consequences of brand personality must be looked at in the aspect of the service environment for further research.

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Understanding the Mismatch between ERP and Organizational Information Needs and Its Responses: A Study based on Organizational Memory Theory (조직의 정보 니즈와 ERP 기능과의 불일치 및 그 대응책에 대한 이해: 조직 메모리 이론을 바탕으로)

  • Jeong, Seung-Ryul;Bae, Uk-Ho
    • Asia pacific journal of information systems
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    • v.22 no.2
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    • pp.21-38
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    • 2012
  • Until recently, successful implementation of ERP systems has been a popular topic among ERP researchers, who have attempted to identify its various contributing factors. None of these efforts, however, explicitly recognize the need to identify disparities that can exist between organizational information requirements and ERP systems. Since ERP systems are in fact "packages" -that is, software programs developed by independent software vendors for sale to organizations that use them-they are designed to meet the general needs of numerous organizations, rather than the unique needs of a particular organization, as is the case with custom-developed software. By adopting standard packages, organizations can substantially reduce many of the potential implementation risks commonly associated with custom-developed software. However, it is also true that the nature of the package itself could be a risk factor as the features and functions of the ERP systems may not completely comply with a particular organization's informational requirements. In this study, based on the organizational memory mismatch perspective that was derived from organizational memory theory and cognitive dissonance theory, we define the nature of disparities, which we call "mismatches," and propose that the mismatch between organizational information requirements and ERP systems is one of the primary determinants in the successful implementation of ERP systems. Furthermore, we suggest that customization efforts as a coping strategy for mismatches can play a significant role in increasing the possibilities of success. In order to examine the contention we propose in this study, we employed a survey-based field study of ERP project team members, resulting in a total of 77 responses. The results of this study show that, as anticipated from the organizational memory mismatch perspective, the mismatch between organizational information requirements and ERP systems makes a significantly negative impact on the implementation success of ERP systems. This finding confirms our hypothesis that the more mismatch there is, the more difficult successful ERP implementation is, and thus requires more attention to be drawn to mismatch as a major failure source in ERP implementation. This study also found that as a coping strategy on mismatch, the effects of customization are significant. In other words, utilizing the appropriate customization method could lead to the implementation success of ERP systems. This is somewhat interesting because it runs counter to the argument of some literature and ERP vendors that minimized customization (or even the lack thereof) is required for successful ERP implementation. In many ERP projects, there is a tendency among ERP developers to adopt default ERP functions without any customization, adhering to the slogan of "the introduction of best practices." However, this study asserts that we cannot expect successful implementation if we don't attempt to customize ERP systems when mismatches exist. For a more detailed analysis, we identified three types of mismatches-Non-ERP, Non-Procedure, and Hybrid. Among these, only Non-ERP mismatches (a situation in which ERP systems cannot support the existing information needs that are currently fulfilled) were found to have a direct influence on the implementation of ERP systems. Neither Non-Procedure nor Hybrid mismatches were found to have significant impact in the ERP context. These findings provide meaningful insights since they could serve as the basis for discussing how the ERP implementation process should be defined and what activities should be included in the implementation process. They show that ERP developers may not want to include organizational (or business processes) changes in the implementation process, suggesting that doing so could lead to failed implementation. And in fact, this suggestion eventually turned out to be true when we found that the application of process customization led to higher possibilities of failure. From these discussions, we are convinced that Non-ERP is the only type of mismatch we need to focus on during the implementation process, implying that organizational changes must be made before, rather than during, the implementation process. Finally, this study found that among the various customization approaches, bolt-on development methods in particular seemed to have significantly positive effects. Interestingly again, this finding is not in the same line of thought as that of the vendors in the ERP industry. The vendors' recommendations are to apply as many best practices as possible, thereby resulting in the minimization of customization and utilization of bolt-on development methods. They particularly advise against changing the source code and rather recommend employing, when necessary, the method of programming additional software code using the computer language of the vendor. As previously stated, however, our study found active customization, especially bolt-on development methods, to have positive effects on ERP, and found source code changes in particular to have the most significant effects. Moreover, our study found programming additional software to be ineffective, suggesting there is much difference between ERP developers and vendors in viewpoints and strategies toward ERP customization. In summary, mismatches are inherent in the ERP implementation context and play an important role in determining its success. Considering the significance of mismatches, this study proposes a new model for successful ERP implementation, developed from the organizational memory mismatch perspective, and provides many insights by empirically confirming the model's usefulness.

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Experimental Studies on Extracorporeal Circulation by Sarns Heart-Lung Machine with Total Prime of Hartman's Solution (Sarns 심폐기의 혈희석 체외순환에 관한 실험적 연구)

  • 김근호
    • Journal of Chest Surgery
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    • v.8 no.2
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    • pp.135-142
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    • 1975
  • Total body perfusion using Sarns Heart-Lung-Machine, five head pump motor system with Travenol disposable bubble oxygenator was attempted in the dogs by the hemodilution method with total prime of buffered Hartman`s solution under moderate hypothermia. The first of all, the functions of Sarns Heart-Lung-Machine and effects of the hemodilution perfusion by buffered Hartman`s solution was studied. At the same time the changes of pressure of artery and vein, gas contents of the blood, and influence on the blood pictures were observed before, during, and after perfusion in 1-2 days. Hemodilution rates were the ranges of 85.0ml/kg to 97.3ml/kg and perfusion flow rates were maintained with the average 80. 5ml/kg/min [the ranges of 73.3ml/kg/min to 92.8ml/kg/min]. Hypothermia was employed between $35^{\circ}C$ and $31^{\circ} of the esophageal temperature. The total body perfusion was continued for 50-60 minutes. In the total cardiopulmonary bypass, atriotomy, ventriculotomy, and atrioventriculotomy were performed respectively. Arterial pressure was ranged approximately between 50 mmHg and 140 mmHg, but generally, it was maintained over 75 mmHg. Venous pressure was measured between 3.8 cm$H_2O$ and 16.0 cm$H_2O$. Optimum oxygenation could be achieved when oxygen flow into the oxygenator was maintained approximately at 5. 5L/min. In this way, the $pO_2$, $pCO_2$, and oxygen saturation were measured before, during, and afterperfusion in 1-2 days. The $pCO_2$ ranged approximately between 26.0 mmHg and 38.5 mmHg, but generally, it was maintained in the average 30.9-32.5mmHg. The $pO_2$ was ranged between 73.0mmHg and 332.2 mmHg, but it was maintained in the average 103.0-219.0 mmHg. Oxygen saturation was measured over 95. 0% during and after extracorporeal circulation respectively. Erythrocyte count, hemoglobin, hematocrit, and leucocyte count were decreased to 49.2%, 49.0%, 49.4%, and 21. 1% of the preoperative value during extracorporeal circulation respectively and these reductions were not recovered until 1-2 days after perfusion. These. resulted from relatively high degree of hemodilution rate and operative bleeding during these experimental studies. The platelets count was also decreased about to 71% during perfusion, on the contrary, it was increased progressively after perfusion and in 1-21 days after perfusion, the value was returned to preoperative contro1 level. Three dogs were all recovered after extracorporeal circulation.

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A study on the theory of 'Eum-yang-Li-Hap (陰陽離合)' in 6th chapter of 'SoMoon (素問)' 'Yellow Emperior's Nei-ching (黃帝內經)' (황제내경(黃帝內經) 소문(素問) 음양이합론(陰陽離合論)에 대한 고찰(考察))

  • Ok, Do-Hoon;Hong, Won-Sik
    • Journal of Korean Medical classics
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    • v.3
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    • pp.501-552
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    • 1989
  • In this thesis, I intend to study the translational and clinical interpretation through the theory of Eum-Yang-Li-Hap', and reached the following conclusions. 1. 'Eum-Yang (陰陽)' in title, means Yin and Yang as method of understanding nature or humanbody, and 'Li-Hap (離合)' in title, means classification and getting together. Especially there are a view that Eum Yang in title means only meridinans within the limit of human body, but the limit needn't, because the word 'Li-Hap of 3Yin-3Yang (三陰三陽之離合)' as meaning of human meridians in the text. 2. The content of the text is generally seperated into 3 parts, the 1st part contents properties of Li Hap of Yin and Yang. 2nd and 3rd parts content the explanation of property of 3Yin and 3Yang, as example of human meridians with local conception, and content nicknames of 3Yin-3Yang and present the Ideo of 'Kae-Hap-Choo (開闔樞)'. 3. 3Yin-3Yang in the text, many of annotators tried to explanate by three types of conception, of human meridians, of the 'Viscera-Bowels (臟腑)', or of the 'Element motions and Natural factors (運氣)'. I think that these three conceptions could be mixed when the text was written, and regarde for the present that 3Yin-3Yang is explanated by the conception of human meridians. 4. 'Eum (陰)' the head-letter of the nicknames of 3Yin-3Yang, I think that it means 'Jok-Gyeong (足經)' related with the words 'The earth belongs to Yin (地爲陰)' in the text. And it i s considered that further studies should be followed on the tail-words of 3Yin-3Yang's nicknams. 5. Kae-Hap-Choo, Used in similitude" as 'Li (離)' of 3Yin-3Yang, are seperated functions by location of 3Yin-3Yang. In text 'Tae-Yang (太陽)' and 'Tae-Eum (太陰)' act as 'Kae (開)', 'Yang-Myeong (陽明)', and 'Gweor-Eum (厥陰)' act as 'Hap (闔)', 'So-Yang (少陽)' and 'So-Eum (少陰)' act as 'Choo (樞).' But there is other theory that Gweor-Eum act as Choo, and So-Eum act as Hap. 6. The theory of Kae-Hop-Choo, including only Jok-Gyeong being main materials of 'Yook Gyeong-Byeon-Jeung (六經辨證) had influence on development of clinical studies. If the theory of Kae-Hap-Choo receives and unions the ideos of '3 burning-Spaces (三焦)', metabolism, etc. more development of medicine is expected.

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A Study on the Quality Assessment Using QFD & FMEA (QFD와 FMEA를 이용한 품질평가에 관한 연구)

  • Park, Chang-Kyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.11
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    • pp.78-87
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    • 2017
  • Recently, the quality of a product or system has becoming increasingly important as it means customer satisfaction. The function, which is recognized as a nature of this quality, means how it functions well so it is the closest to the customer satisfaction. On the other hand, it is becoming more important as safety is closely related to destruction or human injury from accidents for engineers who handle large-scaled structures, such as ships. This study analyzed the function using quality function development (QFD) and considering the function and safety, which are being recognized as important in the structure. In addition, the safety and the quality analysis method based on the customers' needs was analyzed using failure mode and influence analysis (FMEA). In addition, the supplementary materials that are important in terms of the aspect of safety and function for the quality enhancement of a hatchway system were determined by applying a bulk carrier and hatchway. As a result, there are commonly understood items in important supplementary materials and parts, which are determined individually in terms of function and safety, because they can enhance both the function and safety simultaneously. This study shows that designers can improve the quality of products and systems by enhancing these supplementary materials and parts with greater interest.

Experimental Studies on Extracorporeal Circulation by Rygg-Kyvsgaard Heart-Lung Machine, Hartman`s Solution Prime,and Moderate Hypothermia: [Part I] (Hartmann`s 용액으로 충진한 혈희석 체외순환에 관한 실험적 연구: (1보: 심폐기 Rygg-Kyvsgaard 의 혈산화와 혈압 및 혈액상에 미치는 영향))

  • 지행옥
    • Journal of Chest Surgery
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    • v.4 no.2
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    • pp.69-80
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    • 1971
  • Total body perfusion using Rygg-Kyvsgaard Heart-Lung-Machine, Mark IV, Polystan was attempted in the dogs by the hemodilution method with total prime of buffered Hartman's solution and under hypothermia. The first of all, the functions of Rygg--Kyvsgaard Heart-Lung-Machine and the effects of the hemodilution perfusion by buffered Hartman's solution was studied. At the same time the changes of blood pressure, oxygen consumption, and influence on the blood pictures were observed before, during, and in 1-3 days after perfusion. Hemodilution rates were the average 74. 22cc/Kg(the ranges of 67 to 81 cc/Kg) and perfusion flow rates were maintained in the mean 62. 6cc/Kg/min., Although it was possible to check up to 87 cc/ Kg/min. The total body perfusion continued for 60-80 minutes. Hypothermia was employed between $36^{\circ}C$ and $32^{\circ}C$ of the rectal temperature. Arterial pressure was ranged approximately between 68mmHg and 149mmHg, but generally, it was maintained over 80mmHg. Venous pressure was measured between 6.5cm $H_2O$and 11.5cm $H_2O$. Optimum oxygenation can be expected when oxygen flow into the disposable bubble oxygenator was maintained approximately at 3.5 L/min .. Inthis way, the oxygen contents were measured in the mean value of 13.11${\pm}$O.56 vol. % of arterial blood and 8.67+1.08 vol.% of venous blood(P${\pm}$0.86 vol.% in arteriovenous oxygen difference and 2. 97${\pm}$0.62cc/Kg in oxygen consumption were calculated. According to these dates, it is as plain as pikestaff that excellent oxygenation and good tissue perfusion was accomplished. Erythrocyte, hemoglobin and hematocrit were decreased about 38% during extracorporeal circulation and these were not recovered until 1-3 days after perfusion. These decrease was resulted from relatively high degree of hemodilution rate and no blood transfusion to compensate during these experimental studies. The platelets were also decreased about 76% during perfusion, but on the contrary, it was increased progressively after perfusion and in 1-3 days after perfusion was returned to the control level. Leucocyte were also decreased during perfusion, but it was increased progessively after perfusion and in 1-3 days after perfusion exceed the control level. This increase was resulted from postoperative infection of the wound, but its analysis were not changed significantly.

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