• 대한가정학회지
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• 제24권4호
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• pp.147-162
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• 1986

This research has dual purposes. First, it was designed to determine the level of children's spatial environment in the residences, thereby, to make a vision for children's furniture as an industrial design product. Second, it was intened to find out the children's perceptual pattern toward the furniture, thereby to give some implications for future design development. For the second purpose, descriptors were screened with construct validity and their factor structure was identified. The subjects were 1,197 children from 1st grade of elemantary school through 3rd grade of middle school, and their 1,197 parents for the first purpose, and 560 children from 6th grades of elemantary school and 3rd grade of middle school for the second purpose. The first parts of findings were 1) present interests of parents of household above middle income level in Seoul in making their children's spatial environment desirable is quite high. 2) Space segregation stage in terms of physical and conceptual aspects showed very fast development, that is, there will have been very good changes for children's room to be a very well furnished and independent space for them. 3) Children's opinions were quite well reflected when purchasing the present furniture, and this tendency seemed to be more likely happend in future. These findings mentioned above gave and confirmed the visions for future children's furnished environment. The second parts of findings were such that the perceptual pattern for furniture by children showed aesthetic design appearance, functionality and durability, and the characteristic of line. This result impliated especially that designers should be every careful to manipulate or use the line of the furniture products. The 22 representative descriptors selected can be used as an evaluation instrument for furniture products.

• 대한소아치과학회지
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• 제29권3호
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• pp.313-317
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• 2002

어린이는 성인과 다른 악관절 구조를 가지고 있으며 이로 말미암아 견고한 중심교합위를 얻지 못하거나 이원교합(dual bite)의 경우가 많다. 이러한 경향이, 편측저작 등의 치열변화를 초래할 수 있는 습관과 합쳐져 골격적 변화를 초래하게 될 경우, 안면 비대칭이 유도될 수 있다. 이러한 경우의 치료로서 교합유도를 통한 관절의 안정화와 그에 맞는 교합의 재형성을 통한 관절 및 교합의 안정화가 필요하다. 안면 비대칭을 주소로 내원한 5세 어린이에서 편측저작 습관으로 말미암은 우측 편측 구치부 절단교합과 2.5mm의 정중선 불일치가 있었다. 저자들은 activator를 이용하여 악관절 및 교합을 정상위치로 유도한 후 유구치를 주조금관으로 수복하여 양호한 결과를 얻었다.

• 통상정보연구
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• 제6권1호
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• pp.25-50
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• 2004

This study attempts to find out what kind of service quality is considered important by customers in using the Internet shopping mall and suggests the way to activate the customer relationship. The findings based on empirical analysis are shown here. First, empirical analysis of the contextual factors such as gender, education, and experience levels, shows that what customers perceive as most important in the product purchase is security in terms of the payment and personal information service. The second important service quality factor perceived by customers is responsiveness, particularly the rapidity and accuracy of response to their needs and wants. The customers also considered price, quality and diversity of the product as being important. Furthermore, there is no big difference among other service quality factors. Second, in the different gender context, there is no significant difference between the genders. However, the male group shows an even distribution of factors valued in the service quality, whereas female respondents placed stronger emphases on particular aspects of service, such as security, response, reliability and product quality. Third, in the context of different education level, the payment method between graduates and non-graduates has a significant difference. That is, the non-graduates prefer the credit card and saving through ATM, while the graduates use dual payment method using credit card and another payment method together. Therefore, the various payment methods should be considered according to the customer type, namely graduates or non-graduates. Fourth, in the context of different experience level, the result of the empirical analysis of the factors of the service quality shows no great difference between experienced and inexperienced customers. Both types of customer perceive security as the most important. To sum up, the service quality perceived by the customers of Internet shopping malls is empirically analyzed in different contexts such as gender, education, and experience. Then, the device for the customer relationship activation is suggested. It can be utilized as a guideline for the continuing diffusion of the Internet shopping mall, giving it a competitive advantage against other companies.

• 약학회지
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• 제22권3호
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• pp.163-174
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• 1978

차전자(Plantaginis Semen)은 우리나라 전국 각지의 원야와 노방의 자생하는 다년생 초목으로 Plantaginaceae(질경이과)에 속하는 Plantago major L. var. asiatica Decaisne 질경이의 종자를 말하며 그의 성분으로는 다량의 점액, 지방유, pentosan 및 galactan, succinic acid, plantanolic acid, adenine, choline. K-염등이 알려져 있다. 이 차전자는 한방과 민간에서 소염, 이뇨, 진해, 지사제로서 널리 사용되어 왔으며 그의 약리작용에 관해서는 이미 저자들이 가토를 이용한 실험에서 이의 methanol extract가 자궁수축작용, 호흡흥분작용, 혈압강하작용, 장관수축작용, 심장박동의 완제작용, 항이뇨작용이 있음을 보고한 바 있다. 그러나 그의 기전에 관해서는 거의 알려진 바가 없다. 따라서 저자들은 위의 여러가지 작용중 특히 혈압강하작용에 관한 본태를 파악하여 그의 실용성 여부를 구명코자 이 실험을 착수하였다.

• Smart Structures and Systems
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• 제21권3호
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• pp.287-303
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• 2018

Applications of energy harvesting from mechanical vibrations is becoming popular but the full potential of such applications is yet to be explored. This paper addresses this issue by considering an application of energy harvesting for the dual objective of serving as an indicator of structural health monitoring (SHM) and extent of control. Variation of harvested energy from an undamaged baseline is employed for this purpose and the concept is illustrated by implementing it for active vibrations of a pipe structure. Theoretical and experimental analyses are carried out to determine the energy harvesting potential from undamaged and damaged conditions. The use of energy harvesting as indicator for control is subsequently investigated, considering the effect of the introduction of a tuned mass damper (TMD). It is found that energy harvesting can be used for the detection and monitoring of the location and magnitude of damage occurring within a pipe structure. Additionally, the harvested energy acts as an indicator of the extent of reduction of vibration of pipes when a TMD is attached. This paper extends the range of applications of energy harvesting devices for the monitoring of built infrastructure and illustrates the vast potential of energy harvesters as smart sensors.

• 실천공학교육논문지
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• 제8권1호
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• pp.9-14
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• 2016

졸업 조건 인증을 위한 졸업 작품 및 졸업 논문 제출 규정에 따라 설계/제작한 절차를 제시하고, 개선사항을 이론적으로 제안한다. 설계 내용은 태양 에너지로 충전시키는 Li-Po 배터리로 동작하는 쿼드콥터의 자세를 확인하고, PID(Proportional Integral Differential) 제어를 통하여 균형을 유지한 결과이다. 특히 2개의 Li-Po 배터리들을 탑재하고 태양 에너지를 이용하여 하나의 배터리를 충전시키는 동안에 다른 배터리로 구동하며, 배터리 전환 회로는 2종류의 릴레이들을 사용하여 배터리 전환 회로를 구성한다. 완전 충전되지 않았더라도 특정 전압으로 충전된 배터리를 구동중인 배터리와 수시로 절환시켜, 체공시간과 항속거리를 증가시키는 방법을 제안한다.

• Restorative Dentistry and Endodontics
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• 제40권3호
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• pp.195-201
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• 2015

Objectives: The use of chitosan nanoparticles (CNPs) in endodontics is of interest due to their antibiofilm properties. This study was to investigate the ability of bioactive CNPs to remove the smear layer and inhibit bacterial recolonization on dentin. Materials and Methods: One hundred bovine dentin sections were divided into five groups (n = 20 per group) according to the treatment. The irrigating solutions used were 2.5% sodium hypochlorite (NaOCl) for 20 min, 17% ethylenediaminetetraacetic acid (EDTA) for 3 min and 1.29 mg/mL CNPs for 3 min. The samples were irrigated with either distilled water (control), NaOCl, NaOCl-EDTA, NaOCl-EDTA-CNPs or NaOCl-CNPs. After the treatment, half of the samples (n = 50) were used to assess the chelating effect of the solutions using portable scanning electronic microscopy, while the other half (n = 50) were infected intra-orally to examine the post-treatment bacterial biofilm forming capacity. The biovolume and cellular viability of the biofilms were analysed under confocal laser scanning microscopy. The Kappa test was performed for examiner calibration, and the non-parametric Kruskal-Wallis and Dunn tests (p < 0.05) were used for comparisons among the groups. Results: The smear layer was significantly reduced in all of the groups except the control and NaOCl groups (p < 0.05). The CNPs-treated samples were able to resist biofilm formation significantly better than other treatment groups (p < 0.05). Conclusions: CNPs could be used as a final irrigant during root canal treatment with the dual benefit of removing the smear layer and inhibiting bacterial recolonization on root dentin.

• 조명전기설비학회논문지
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• 제22권5호
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• pp.86-94
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• 2008

본 논문은 PV(Photovoltaic) 어레이의 출력을 높이기 위해 PC 기반의 퍼지제어를 이용한 태양추적 시스템을 제안한다. 태양 추적시스템은 광센서의 신호에 의해 구동하는 두 개의 DC 모터로 동작한다. 두 축의 제어는 파라미터의 불확실성 및 비선형 특성 때문에 쉽지 않다. 최근 퍼지제어, 신경회로망 및 유전자 알고리즘 등의 인공지능 제어에 대한 연구가 많이 이루어지고 있다. 그 중 퍼지제어는 비선형 제어를 원활하게 수행할 수 있으며 파라미터 변동 및 비선형 특성에 대한 강인성 및 고성능의 특징을 가지고 있다. 따라서 퍼지제어는 설정된 오차 값과 비선형의 고도각 및 방위각 오차 값을 비교하여 추적 시스템 구동을 위해 사용된다. 본 논문에서는 PV 어레이의 출력 향상을 위해 퍼지제어기를 설계하고 종래의 Pl 제어기와 성능을 비교하며 평가한다. 실험을 통한 데이터는 제시한 제어기의 타당성을 입증한다.

• 조명전기설비학회논문지
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• 제22권5호
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• pp.31-40
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• 2008

최근 FPD 산업에서 물류이송장비의 전원장치로 비접촉 전원장치에 관한 연구가 활발히 진행되고 있다. 양산 라인에 적용되고 있는 물류장비의 비접촉 전원장치는 주로 직선구간을 왕복하고, 이송대차가 한 대인 경우에 적용하고 있다. 그러나 곡선 구간과 이송대차가 다수인 경우의 물류이송장비에는 적합하지 않다. 따라서 본 논문은 직 곡선 구간이 혼용되어진 구조이고, 이송대차가 한 대 이상으로 구동되는 물류이송장비의 비접촉 전원장치 시작품에 적용하였고, 적용된 비접촉 전원장치의 회로 구조는 풀 브릿지 구조를 갖는 직 병렬 공진 DC/DC 컨버터 회로로 하여 회로해석, 제어방법, 특성평가, 실험을 통한 적용 가능성에 대한 연구를 행하였다. 또한 비접촉 전원장치의 전체 제어는 1차측 전원공급장치에 일정한 공진전류를 제어하기 위해 듀티 제어를 사용하였고, 2차측 전원공급장치의 출력전압을 일정하게 유지하기 위해 다수의 이송대차가 자체 제어를 하도록 구성하였다. 실제 2대의 이송대차를 제작하여 직 곡선 구간을 구성하고, 물류이송장비를 운용하여 양호한 특성으로 적용 가능함을 알 수 있었다.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2008년도 정보통신설비 학술대회
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• pp.372-375
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• 2008

IEEE 802.11e standardized the EDCA mechanism to support the priority based QoS. And the virtual collision handler schedules the transmission time of each MAC frame using the internal back-off window according to the access category(AC). This can provides the differentiated QoS to real-time services at the medium traffic load condition. However, the transmission delay of MAC frame for real-time services may be increased as the traffic load of best effort service increases. It becomes more critical when the real-time service uses a compressed mode video codec such as moving picture experts group(MPEG) 4 codec. That is because each frame has the different importance. That is, the I-frame has more information as compared with the P- and the B-frame. In this paper, we proposed a buffer management algorithm based on the frame importance and the delay bound. The proposed algorithm is consisted of the traffic regulator based on the dual token bucket algorithm and the active queue management algorithm. The traffic regulator reduces the transmission rate of lower AC until that the virtual collision handler can transmit an I-frame. And the active queue management discards frame based on the importance of each frame and the delay bound of head of line(HoL) frame when the channel resource is insufficient.