• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 춘계학술대회 논문집
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• pp.249-252
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• 2005

Recently, as the industrial demand for small quantity batch production of sheet metal components, the application of dieless forming technology to production of these component rise with the advantages of the reduction in manufacturing cost and time. In dieless forming processes, the determination of moving path of tool plays an important role in producing successfully formed parts. In order to obtain the optimized moving path of tool avoiding forming failure, it is necessary to examine the forming limit of sheet material. Therefore, in this study, as the new criterion to evaluate the formability of sheet material in dieless forming processes FDD(feeding depth diagram) with respect to feeding depth and punch diameter is proposed. Thus, the FDD for the sheet materials of STS304 and Ti-grade2 were obtained from a series of FDT(feeding depth test). In addition the possibility of the application of FLD in judging forming severity in dieless forming processes was investigated by comparing the results of FE analyses based on FLD and experimental FDT.

• 대한간호학회지
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• 제21권1호
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• pp.89-116
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• 1991

The purpose of this study was to describe mother -infant interacting behavior patterns related to newborn infant feeding and to explore the mother's cultural belief about their infant. The data collection was conducted by observation and interview. Twenty-five mothers and their newborn infants who were normally delivered and were also planned to breast feed were comprised as the subjects of this study. All subjects were interviewed and observed individuaily at 1 to 5 days after the delivery at the hospital, mid -wife's clinic, Maternal Child Health Center and their home throughout the country from remote area to big city, The observation data were recorded with symbolic letter on a recording sheet newly developed as a result of preliminary study. The interview data were taperecorded and then recorded in narrative form. Mother - infant interaction behaviors in early feeding period were analyzed based on 19 analytic sub-categories and their composing elements. Unit of analysis were mother, infant and mother -infant dyad. 8 analytic categories draw from the data. Each were preparation, instrument, interaction inducing, evaluation referred to mother's behavior, preparation, instrument, interaction inducing referred to infant's behavior and synchronic behaviors referred to mother - infant dyad. Frequencies of behavior items based on the categories were converted to percent. The result showed that in mother's preparation behavior, the breast condition of Korean mother can be an affecting factor for mother - infant interaction during feeding, and vocalization behavior was observed most frequently in interaction inducing behavior while the least frequent behavior observed was contacting. Subcultural characteristics of mother - infant interaction behaviors were analyzed for their relationships between groups of mothers who have lived in remote area vs urban area, and who were multipara vs primipara. Using a chi -square test, there were statistically significant relationships in the activity of psychological readiness in preparation behavior and the movement of extremities for the position of instrumental behavior in both groups. However, interaction inducing behaviors were not related with statistical significance in any set of groups. Accomplishment of marriage, bonding and emotional mediation of family members were the categories related to mother's cultural belief about the infant in aspect of functional values. Infant at birth is considered little more than a biological organism without social capabilities. Although the newborn infant is still be attached to his mother, he makes his mother extend her territoriality. The mother's interacting behavior toward her infant based on those beliefs appeared task oriented, separative behavioral series. On the other hand, it was seen that infant reacted independently to his mother's behavior by the in-nate perceptual abilities. Those independent behavioral series of mother and infant on the feeding situation were synchronized at any moment. Nurses are In a unique position to teach mothers about their infant's capabilities and help reducing some of uncertainty about infant's behaviors. Study results indicated that the informations infant's social capabilities and breast feeding should be given to the mothers. The results of this study have several implications for nursing. First, the study results will be used as fundamental resources for the development of the assessment tool about the early mother - infant interaction. Second, the results could be a relevant information in the fied. I of maternal child nursing education as real and useful data. Third, the behavioral patterns of early mother - infant interaction which were classified based on the qualitative analysis could be used for nursing theory development as very fundamental data.

• 한국수산과학회지
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• 제2권2호
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• pp.161-172
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• 1969

Ten experimental tuna long line fishing operations were performed with the long lines A and B, in combination casting orders of BA and AB. The long line B differs from A in its additional main line length per basket and its greater depth of submersion (Table 1). The BA casting order results in an AB hauling order, so that the long line B is casted at an earlier time of a day and fishes for a longer period than A line (fig. 2). The number of fish caught was divided into subclasses in order to be subjected to $x^2-tests$ (Table 2). The first series of $x^2-tests$ were calculated using the hooking rates of two subclasses with other factors pooled (Table 3). The second series of $x^2-tests$ were calculated to obtain the interactions between two subclasses when other factors differed (Table 4). Attention was paid to the extremely small interactions as well as to the large interactions in order to find out whether a factor functions in the same way or in a contradictory way when the other factors involved differ. The test result is summarized in Table 5. The relationship between the hook casting time (relative to the sunrise time) and the hooking rates reveals the feeding behavior of particular species (fig. 3) A high hooking rate for yellowfin tuna shown in the period from one hour before sunrise to the moment of sunrise suggests that they feed actively in that period. Their poor hooking rate on earlier casted hooks suggests that they do not feed well under conditions of darkness and that they feed best while the hooks are sinking. Furthermore it is likely that yellowfin tuna maintain a shallow depth in the daytime, for the $x^2$ interaction between the line casting order BA and AB shows their persistant preferance of the long line A regardless of line casting order. Bigeye tuna show their feeding behavior under conditions of darkness, and show a preference for the sea's deeper layer. Alepisaurus borealis (Gill) show their feeding behavior under conditions of darkness more significantly than the bigeye tuna and their preferance for deep layers is also more significant. Marlins (mainly Makaria mazara) show a feeding behavior which is similar to the yellowfin tuna. The author emphasizes that certain variations of the hooking rates in relation to the line easting time were caused by an inadequate fishing depth as well as by the fish preference for a particular feeding time. When the part of the line casted in pre-dawn hours and hauled in the pre-sunset hours show a significantly lower hooking rate than other parts of the line, then it is concluded that tile hooks settled in a sea layer too deep for feeding.

• 한국정밀공학회지
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• 제23권9호
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• pp.76-83
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• 2006

Machining accuracy is closely related with tool deflection induced by cutting forces. In this research, cutting forces and tool deflection in end milling are expressed as a closed form of tool rotational angle and cutting conditions. The discrete cutting fores caused by periodic tool entry and exit are represented as a continuous function using the Fourier series expansion. Tool deflection is predicted by direct integration of the distributed loads on cutting edges. Cutting conditions, tool geometry, run-outs and the stiffness of tool clamping part are considered together far cutting forces and tool deflection estimation. Compared with numerical methods, the presented method has advantages in prediction time reduction and the effects of feeding and run-outs on cutting forces and tool deflection can be analyzed quantitatively. This research can be effectively used in real time machining error estimation and cutting condition selection for error minimization since the form accuracy is easily predicted from tool deflection curve.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.781-785
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• 2005

Cutting forces and tool deflection in end milling are represented as the closed form of tool rotational angle and cutting conditions. The discrete cutting forces caused by tool entry and exit are continued using the Fourier series expansion. Tool deflection is predicted by direct integration of the distributed loads on cutting edges. Cutting conditions, tool geometry, run-outs and the stiffness of tool clamping pan are considered for cutting forces and tool deflection estimation. Compared to numerical methods, the presented method has advantages in short prediction time and the effects of feeding and run-outs on cutting forces and tool deflection can be analyzed quantitatively. This research can be effectively used in real time machining error estimation and cutting condition selection for error minimization since the ferm accuracy is easily predicted by tool deflect ion curve.

• 대한한방부인과학회지
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• 제31권4호
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• pp.128-146
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• 2018

Objectives: This study was performed to analyze the prescriptions of Korean herbal medicine which had been commonly used during postpartum period. Methods: We searched literature on postpartum cares with Korean Herbal medicine in 4 domestic search engines. After that, we conducted eligibility screening based on inclusion and exclusion criteria. Results: 1. We selected total 48 studies. There were 40 clinical studies (25 case reports and 15 case series) and 8 animal experimental studies. 2. Of the 40 clinical studies, other treatments were used together with herbal medicine : acupuncture (28), chuna manipulation (3), and pharmacopuncture (5). 3. Of the 25 case reports, the most common symptoms were musculoskeletal symptoms (8), followed by mental disorders including postpartum depression (5). Various prescriptions of herbal medicine were used depending on the diseases or symptoms. 4. In 15 case series, 665 subjects in 11 case series had taken Saenghwa-tang-gagam within 1~2 weeks after childbirth, and the average duration of Saenghwa-tang-gagam administration were $9{\pm}4.97$ days. 498 subjects in 9 studies were breast-feeding, and there were no side effects reported. 5. All experimental studies were about the recovery, the immunity and the breast-feeding associated puerperal characteristics. Also, 3 studies used Saenghwa-tang as an intervention. Conclusions: Saenghwa-tang can be commonly used for the purpose of prevention and care of the postpartum symptoms within the first 1~2 weeks after childbirth for 10 days. Also, various prescriptions of herbal medicine may be used depending on the diseases or symptoms, and can be conducted with other treatments like acupuncture, cupping, moxibustion, pharmacopuncture and chuna manipulation.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.107-108
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• 2006

This paper shows the design optimization of the paper feeding mechanism under dynamic behavior by using commercial codes of RecurDyn/MTT2D and RecurDyn/AutoDesign which are developed by functionBay, Inc. A virtual mockup for dynamics analysis of the paper feeding mechanism is build on RecurDyn/MTT2D and is simulated. Flexible paper is represented as a series of rigid bars connected by revolute joints and rotational spring dampers. Paper is fed by a contact and friction mechanism on rollers or guides. The slip of the paper and nip force of rollers are measured to estimate the system performance. After a simulation, these performances are automatically send to RecurDyn/AutoDesign which is a sequential approximate optimization tool based on the response surface modeling. RecurDyn/AutoDesign makes the approximate objective function and computes the optimized design points of the design variables and gives them to analysis tool. And then the simulation is repeated with the updated design variables. These processes are repeated until finding a tolerable design optimization. In this paper, a paper feeding mechanism is introduced and it is optimized with the proposed algorithms.

• Journal of information and communication convergence engineering
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• 제18권3호
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• pp.162-166
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• 2020

The present paper presents an array antenna of a microstrip patch for 5G applications. Four rectangular microstrip patch elements are arranged in parallel and series to form an array antenna. Two insets are made on both sides of each patch element to achieve a wide frequency bandwidth of 23.97-31.60 GHz. To attain a high gain and wider bandwidth, the microstrip patch antenna is fed using series and corporate feeding networks. Further, three director elements on top of the top-most patch elements, and one reflector element at the open end of each patch element, are added. The addition of the Yagi elements improved the overall gain and acquired a higher radiation efficiency throughout the operating frequency bandwidth, with the array antenna achieving a maximum peak gain of 8.7 dB. The proposed antenna is built on a low-loss and low-cost substrate of FR4-eproxy. The proposed antenna design with a simple structure is suitable for Internet of Things and 5G applications.

• 한국연소학회지
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• 제7권3호
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• pp.16-22
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• 2002

Combustion performance of an internally cycloned circulating fluidized bed for paper sludge was discussed through a series of batch type experiments. Operation parameters such as water content, feeding mass of sludge and secondary air injection rate were varied to find out the effect on the combustion performance, which was examined with carbon conversion rate and pollutant emission such as CO and NOx. A conventional solid fuel reaction was observed in the experiments of varying water content and feeding mass of the sludge, which is characterized with kinetic limited reaction zone, diffusion limited reaction zone and transition zone. Secondary air injection with swirl enhances the mixing of the gas phase as well as the solid phase, and improves combustion efficiency accompanied with higher carbon conversion rate and lower pollutant emission rate.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2003년도 종합학술발표회 논문집 Vol.13 No.1
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• pp.413-417
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• 2003

In this paper, a series-fed microstrip array antenna utilized a sub-array with a waveguide slot feeding is presented. This sub-array can reduce the feed loss compared with a full microstrip feed network. The sub-array has been designed both for a broad reflection bandwidth and a flat gain bandwidth from 40.5 GHz to 43.5 GHz. The $24{\times}24$ array antenna has been implemented with the maximum gain of 32.4 dBi.