This study performed an inverse detection of fiber stiffness degradation that occurs due to damages in free vibrating composite structures. Five unknown parameters are considered to determine the fiber stiffness which is a modified form of the bivariate Gaussian distribution function. The proposed approach is more feasible than the conventional element-based damage detection method from the computational efficiency because a finite element analysis coupled with a genetic algorithm using a small number of unknown parameters is performed. The numerical examples show that the proposed technique is a feasible and practical method, which can prove the location of a damaged region as well as inspect the distribution of deteriorated fiber stiffness although there is a small difference in dynamic characteristics between damaged and undamaged structures.

Bi0.5Na0.5TiO3 (BNT) based ceramics are considered potential lead-free alternatives for Pb(Zr,Ti)O3(PZT) based ceramics in various applications such as sensors, actuators and transducers. However, BNT-based ceramics have lower electromechanical performance as compared with PZT based ceramics. Therefore, in this work, lead-free bulk 0.99[(Bi0.5Na0.5)0.935Ba0.065](1-x)LaxTiO3-0.01SrZO3 (BNBTLax-SZ, with x = 0, 0.01, 0.02) ceramics were synthesized by a conventional solid state reaction The crystal structure, dielectric response, degree of diffuseness and electric-field-induced strain properties were investigated as a function of different La concentrations. All samples were crystallized into a single phase perovskite structure. The temperature dependent dielectric response of La-modified BNBT-SZ ceramics showed lower dielectric response and improved field-induced strain response. The field induced strain increased from 0.17% for pure BNBT-SZ to 0.38 % for 1 mol.% La-modified BNBT-SZ ceramics at an applied electric field of 6 kV/mm. These results show that Lamodified BNBT-SZ ceramic system is expected to be a new candidate material for lead-free electronic devices.

흰가루병에 저항성이 있는 절화장미 품종을 육성하기위하여 2007년 수량이 많고 절화수명이 긴 다홍색의 스탠다드 ‘Aladin’ 품종과 화형이 우수하고 흰가루병에 저항성이 있는 적색 스탠다드 ‘Red Queen’ 품종을 각각모본과 부본으로 인공교배를 실시하였다. 2008년 획득한종자를 파종하여 219개의 실생 개체를 얻었으며 꽃잎수가 5개 미만인 것을 제외하고 2009-2011년까지 3차에 거쳐 특성평가를 실시한 후 ‘원교 D1-179’를 최종 선발하여 ‘Antique Curl’로 명명하였다. ‘Antique Curl’은 복색으로 노랑색(Y2C) 분홍색(R49A)이 혼합되어 있으며, 화형은 고심형, 꽃잎수는 56.7장으로 대조품종인 ‘MoonLight’보다 약 20장 더 많다. 화폭은 12.3cm로 대조품종보다 약간 작았다. 1m2당 연간 채화 가능한 수량은 135.5본이며 절화장은 65.8cm, 절화경경은 5.8mm의 절화 특성을 보였다. 또한 절화수명은 16.8일이며 흰가루병 저항성을 가지고 있으며 기호도 평가에서도 4.0을 획득하여 대조품종 보다 1.0 높은 기호도를 보였다. ‘Antique Curl’의품종보호권(품종보호: 제4456호)은 2013년 4월에 국립종자원을 통해 정식 등록되었다.

Bi2Te3 related compounds show the best thermoelectric properties at room temperature. However, n-type Bi2Te2.7Se0.3 showed no improvement on ZT values. To improve the thermolectric propterties of n-type Bi2Te2.7Se0.3, this research has Cu-doped n-type powder. This study focused on effects of Cu-doping method on the thermoelectric properties of n-type materials, and evaluated the comparison between the Cu chemical and mechanical doping. The synthesized powder was manufactured by the spark plasma sintering(SPS). The thermoelectric properties of the sintered body were evaluated by measuring their Seebeck coefficient, electrical resistivity, thermal conductivity, and hall coefficient. An introduction of a small amount of Cu reduced the thermal conductivity and improved the electrical properties with Seebeck coefficient. The authors provided the optimal concentration of Cu0.1Bi1.99Se0.3Te2.7. A figure of merit (ZT) value of 1.22 was obtained for Cu0.1Bi1.9Se0.3Te2.7 at 373K by Cu chemical doping, which was obviously higher than those of Cu0.1Bi1.9Se0.3Te2.7 at 373K by Cu mechanical doping (ZT=0.56) and Cu-free Bi2Se0.3Te2.7 (ZT=0.51).

New lead-free piezoelectric ceramics 0.96[{Bi0.5 (Na0.84 K0.16)0.5}1-xLax(Ti1-y Nby)O3]-0.04SrTiO3 (BNKT-ST-LN, where x = y = 0.00 ≤ (x = y) ≤ 0.015) were synthesized using the conventional solid-state reaction method. Their crystal structure, microstructure, and electrical properties were investigated as a function of the La and Nb (LN) content. The X-ray diffraction patterns revealed the formation of a single-phase perovskite structure for all the LN-modified BNKT-ST ceramics in this study. The temperature dependence of the dielectric curves showed that the maximum dielectric constant temperature (Tm) shifted towards lower temperatures and the curves became more diffuse with an increasing LN content. At the optimum composition (LN 0.005), a maximum value of remnant polarization (33 C/cm2) with a relatively low coercive field (22 kV/cm) and high piezoelectric constant (215 pC/N) was observed. These results indicate that the LN co-modified BNKT-ST ceramic system is a promising candidate for lead-free piezoelectric materials.

바이폴라막을 제조하기 위하여 sulfonated Poly(ether ether ketone)과 aminated polysulfone을 double casting 하고, 막의 내구성 향상을 위해 2시간 동안 표면불소화 처리를 하였다. 각각의 이온교환고분자 막은 FT-IR, 함수율, IEC, 이온전도도 등의 특성평가를 진행하였으며 제조된 막으로 차아염소산발생 실험을 진행하였다. 그 결과 Trimethylamine함량과 전류밀도가 차염발생량에 영향을 주는 것으로 나타났으며, 아민 함량과 전류밀도가 높아짐에 따라 차염발생량이 증가하였다.

The effect of sintering temperature on the microstructure, electrical and dielectric properties of (V, Mn, Co, Dy, Bi)- codoped zinc oxide ceramics was investigated in this study. An increase in the sintering temperature increased the average grain size from 4.7 to 10.4 μm and decreased the sintered density from 5.47 to 5.37 g/cm3. As the sintering temperature increased, the breakdown field decreased greatly from 6027 to 1659 V/cm. The ceramics sintered at 900 oC were characterized by the highest nonlinear coefficient (36.2) and the lowest low leakage current density (36.4 μA/cm2). When the sintering temperature increased, the donor concentration of the semiconducting grain increased from 2.49 × 1017 to 6.16 × 1017/cm3, and the density of interface state increased from 1.34 × 1012 to 1.99 × 1012/cm2. The dielectric constant increased greatly from 412.3 to 1234.8 with increasing sintering temperature.

이 연구는 경표피흡수를 위하여 큐빅액정의 자기조직체의 형성에 관한 것이다. 복수 수산기 (-OH)를 가지는 친수부에 4개의 메칠 그룹을 가지는 양친매성지질인 diglyceryl phytylacetate (DGPA) 를 합성하여 다양한 성능평가를 수행하였다. DGPA의 유화력은 1%의 적은 농도에서도 고 내상의 물을 함유하는 안정한 W/O water-in-oil)에멀젼이 유지되었다. DGPA, dimethicone (2CS), water의 3성분 계의 특정영역에서, 안정한 큐빅상의 액정이 형성되었다. 3상 구조도 작성을 통하여 큐빅 액정영역, 헥 사고날 영역, 물과 헥사고날이 혼제된 영역, 역미셀 영역을 확인하였고, SAXS (small angled x-ray scattering)분석을 통하여 그 구조를 증명하였다. 화장품의 응용으로, 큐보좀 (cubosome)에 10%의 마그 네슘아스코르빌포스페이트, 5％의 피리독신트리헥사데카노에이트를 봉입하여 캡슐화하였다. 큐보좀의 occlusive 효과는 역미셀(reverse micelle)보다 1.7배 우수한 효과를 가졌다. 큐보좀을 분산제인 poloxamer를 사용하여 W/O 에멀젼을 만든 것으로부터 큐빅구조의 액정상으로 회복되는 것을 새롭게 발견하였다. 따라서, DGPA의 양친매성지질의 특성을 이용하여, 큐빅상의 액정을 형성하는 기재로써 화 장품 산업과 의약품분야에서 경표피흡수제로써 응용이 가능할 것으로 기대된다.

Carousel type rotating molding machine is a plastics molding method that is adapted to producing relatively large and seamless parts which are partially or totally enclosed. So it is used to produce the big septic tank, storage tray, icebox, central reservation and so on. Rotating molding method are Rock and Roll, Shuttle, Carousel type, etc. In this study, to develop Carousel type rotating molding machine, its 3D model has designed. Also, to confirm the performance of this model, the theoretical and experimental analysis were carried out under condition of shape and structure of rotating unit and heating unit in molding machine

충남농업기술원 예산국화시험장에서 생장이 균일하고 조기개화성인 스프레이국화 신품종을 육성하기 위하여 모본으로 백/자주색 홑꽃의 ‘Handsome’을 부본으로 백/자주색 홑꽃의 ‘Yes Morning’을 인공 교배하여 실생종자를 채종하였다. 2005년 실생집단으로부터 개화가 균일하고 볼륨감이 우수한 개체를 선발하여 ‘SP05-014-08’로 계통명을 부여하였고, 2006년부터 2008년까지 3년간에 걸쳐 주년 생산성 검정을 통해 ‘Yes Now’을 육성하였다.‘Yes Now’의 자연개화기는 10월 하순경으로 촉성 및 억제재배가 가능하다. ‘Yes Now’는 홑꽃이고 꽃잎은 복색계통인 백/자주색(Red-Purple 59A)이며 화심의 색은 녹황색(Yellow Green 144C)이다. 꽃의 직경은 5.2cm이고 착화수는 본당 13.2개이며 절화수명은 18.8일로 긴 편이다.개화반응주수는 7.0주로 빠른편이고, 줄기가 굵고 볼륨이우수하여 절화 생산량이 많은 편이다. 재배상 유의점은고온기에 화색이 변색되므로 서늘하게 관리하여야 한다.

국화 ‘Amber’는 경남농업기술원 화훼연구소에서 2010년에 육성한 스프레이 국화 신품종으로 2006년도에 복색 홑꽃형의 스프레이 국화 ‘Delmont’ 품종을 모본, 성장세가 좋은 복색 홑꽃형 스프레이 국화 ‘Moulin Rouge’품종을 부본으로 교배하여 육성하였다. 2007에서 2009년까지 춘계 억제재배와 하계 촉성재배를 포함하는 특성검정을 통해 최종적으로 ‘Amber’를 육성하였다. ‘Amber’품종의 자연개화기는 10월 31일이며, 전조와 차광처리에의한 일장조절에 의해 연중 생산이 가능하다. 이 품종은복색 꽃잎을 가진 홑꽃형으로 성장세가 매우 좋고 개화반응주기는 7주이다. 가을재배에 있어서 화경은 5.5cm, 본당 착화수가 11.2개이고, 절화수명은 26.8일이었다. 춘계차광재배에서의 단일처리 후 개화소요일수가 49일이었다.이 품종은 흰녹병에 중도저항성을 나타내고 있으며, 대조품종에 비해 기호도도 높았다.

Numerical analysis of a Ni-PZT stacked piezoelectric micro actuator is investigated for the prediction of mechanical behavior as a preceding research for the manufacturing of three dimensional micro structures. Finite element method is adopted to examine the simulation of a piezoelectric actuator according to applied direction of voltage, by researching displacement characterization of piezoelectric material through piezoelectric theory. PZT-4 is selected as a piezoelectric material. And bimorph finite element modeling is employed to study the response of Ni-PZT bi-layered micro actuator under the various input voltages. The results are presented as maximum displacement values under each applied voltages. Maximum displacement of 0.71μm at 60V is obtained

Carbon nanotube-dispersed bismuth telluride matrix (CNT/Bi2Te3) nanopowders were synthesized by chem- ical routes followed by a ball-milling process. The microstructures of the synthesized CNT/Bi2Te3 nanopowders showed the characteristic microstructure of CNTs dispersed among disc-shaped Bi2Te3 nanopowders with as an average size of 500 nm in-plane and a few tens of nm in thickness. The prepared nanopowders were sintered into composites with a homogeneous dispersion of CNTs in a Bi2Te3 matrix. The dimensionless figure-of-merit of the composite showed an enhanced value compared to that of pure Bi2Te3 at the room temperature due to the reduced thermal conductivity and increased electrical conductivity with the addition of CNTs.

This paper deals with the picking batch size which a bi-directional carousel system can be feasible. The items that customers order are retrieved from the bins of carousel with batch size. The mathematical equations representing rotary travel distance and retrieval lead time to pick a given batch size are derived. Rotary travel distance represents the distance which carousel system rotates to retrieve items in a batch. The bi-directional carousel system rotates to minimize the travel distance in retrieving the items in a batch. Rotary travel distance and retrieval lead time are analyzed for the batch size through the simulation approach. From the simulation, the retrieval batch size that carousel system can be feasible is obtained. A numerical example is shown to explain the solution procedure.

Many retailer store managers are experiencing the situation where some customers balk at purchasing products if the stock is low. In this paper, we extend the single period newsvendor model in an environment of customer balking behavior occurring at double threshold inventory levels assuming the chance of sales during balking is a discrete function of inventory level. Our analysis is based on the assumption that only the mean and the variance of demand are known, without assuming any specific distributional form. We derive the explicit general expression of optimal order quantity with unknown distribution of demand with double threshold inventory levels of customer balking. Then, we illustrate the concepts developed here through simple numerical examples and conclude the future research topics under balking situation.

時間은 일정한 速度로 변함없이 흘러간다. 그러나 사람들은 자신이 처한 환경 과 사연에 따라 시간의 長短과 遲速을 느낀다. 시인들은 시간의 장단과 지속으로 인한 인생사의 애상과 情恨과, 그리고 시간의 流速을 조절할 수 없는 인간의 한계 등을 노래하면서 과거ㆍ현재ㆍ미래의 시간들을 混淆해서 美麗하게 풍자했다. 당나라 白居易는 ｢長恨歌｣와 ｢琵琶行｣에서, 시간과 인간사를 연계시켜 애환 과 정한과 인생무상 등 풍자와 은유로 美麗하게 형상화했다. ｢장한가｣는 玄宗과 楊貴妃의 사랑, 양귀비의 비극적인 죽음, 현종이 죽은 양귀비를 그리워하는 情恨, 그리고 시아버지와 子婦의 不倫을 시간의 추이에 따라 다양하게 풍자했다. 首句 에서 ‘重色’ = ‘傾國’임을 풍자했고, 末句에서 ‘此恨’ = ‘無絶期’는 불륜이 영원히 세상 전해질 것을 풍자한 것이다. 그리고 양귀비의 출세로 당시 부모들이 ‘不重生男’하고 ‘重生女’했다고 하여 男兒 선호사상에서 女兒 선호사상으로 바뀐 것 등을 풍자했다. ｢장한가｣에서 시간과 관련된 대표적인 名句는, ‘天旋地轉迴龍馭’, ‘春風桃李花開日’, ‘秋雨梧桐落葉時’, ‘悠悠生死別經年’과 ‘昭陽殿裏恩愛絶’, ‘蓬萊宮中日月長’과 ‘天長地久有時盡’, ‘此恨緜緜無絶期’ 등이다. ｢비파행｣은 백거이 자신의 45년간의 不遇落拓한 삶과, 長安 제일의 琵琶 名人 이었던 退妓의 기구한 일생을 시간의 흐름과 연계하여 다정다감하게 형상화했다. ｢비파행｣의 末句에서 눈물을 가장 많이 흘린 이가 ‘江州司馬’ 자신이라고 한 것 은, 시인 자신은 원대한 포부와 높은 학문을 가지고도 不遇落拓했음을 은유한 것 이다. 그리고 이를 후세에 전하기 위해 ｢비파행｣을 썼다. ｢비파행｣에서 시간과 관련된 대표적인 名句는, ‘千呼萬喚始出來’, ‘今年歡笑復明年’, ‘秋月春風等閑度’, ‘暮去朝來顔色故’, ‘門前冷落鞍馬稀’, ‘老大嫁作商人婦’, ‘終歲不聞絲竹聲’, ‘春江花朝秋月夜’ 등 이다. 그리고 시인 자신의 不遇落拓함을 은유한 句는 ‘同是天涯淪落人’, ‘謫居臥病尋陽城’, ‘江州司馬靑衫濕’ 등 이다. 문학과 시간은 밀접한 관계가 있다. 문학은 시간의 흐름에 따라 일어난 기쁨과 슬픔을 문자로 교직하여 표현한 것이다. 시어에는 과거ㆍ현재ㆍ미래의 시간들이 混淆되어 있다. 이 混淆된 時制와 시간의 長短과 遲速의 의미와 함께 풍자와 은 유의 세계를 이해해야, 한시 교육을 바르게 할 수 있다. 본고는 ｢장한가｣와 ｢비파행｣에 내재된 時制와 시간의 장단과 지속과 풍자와 은유의 세계를 분석했다. 본고가 한시 교육과 지도에 활용되기를 기대한다.

We have examined the co-doping effects of 1/2mol% NiO and 1/4mol% Cr2O3 (Ni:Cr=1:1) on the reaction,microstructure, and electrical properties, such as the bulk defects and the grain boundary properties, of ZnO-Bi2O3-Sb2O3 (ZBS;Sb/Bi=0.5, 1.0, and 2.0) varistors. The sintering and electrical properties of Ni,Cr-doped ZBS, ZBS(NiCr) varistors werecontrolled using the Sb/Bi ratio. Pyrochlore (Zn2Bi3Sb3O14), α-spinel (Zn7Sb2O12), and δ-Bi2O3 were detected for all ofcompositions. For the sample with Sb/Bi=1.0, the Pyrochlore was decomposed and promoted densification at lowertemperature by Ni rather than by Cr. A homogeneous microstructure was obtained for all of the samples affected by α-spinel.The varistor characteristics were not dramatically improved (non-linear coefficient, α=5~24), and seemed to formZni..(0.17eV) and Vo.(0.33eV) as dominant defects. From impedance and modulus spectroscopy, the grain boundaries werefound to have been divided into two types, i.e., one is tentatively assigned to ZnO/Bi2O3 (Ni,Cr)/ZnO (0.98eV) and the otheris assigned to a ZnO/ZnO (~1.5eV) homojunction.

In this study we aimed to examine the co-doping effects of 1/6mol% Co3O4 and 1/4mol% Cr2O3 (Co:Cr=1:1)on the reaction, microstructure, and electrical properties, such as the bulk defects and the grain boundary properties, of ZnO-Bi2O3-Sb2O3 (ZBS; Sb/Bi=0.5, 1.0, and 2.0) varistors. The sintering and electrical properties of Co,Cr-doped ZBS, ZBS(CoCr)varistors were controlled using the Sb/Bi ratio. Pyrochlore (Zn2Bi3Sb3O14), α-spinel (Zn7Sb2O12), and δ-Bi2O3 were formed inall systems. Pyrochlore was decomposed and promoted densification at lower temperature on heating in Sb/Bi=1.0 by Cr ratherthan Co. A more homogeneous microstructure was obtained in all systems affected by α-spinel. In ZBS(CoCr), the varistorcharacteristics were improved (non-linear coefficient, α=20~63), and seemed to form Zni..(0.20eV) and Vo.(0.33eV) asdominant defects. From impedance and modulus spectroscopy, the grain boundaries were found to be composed of anelectrically single barrier (0.94~1.1eV) that is, however, somewhat sensitive to ambient oxygen with temperature. The phasedevelopment, densification, and microstructure were controlled by Cr rather than by Co but the electrical and grain boundaryproperties were controlled by Co rather than by Cr.

We aimed to examine the co-doping effects of 1/6mol% Mn3O4 and 1/4mol% Cr2O3 (Mn:Cr=1:1) on the reaction,microstructure, and electrical properties, such as the bulk defects and grain boundary properties, of ZnO-Bi2O3-Sb2O3 (ZBS;Sb/Bi=0.5, 1.0, and 2.0) varistors. The sintering and electrical properties of Mn,Cr-doped ZBS, ZBS(MnCr) varistors werecontrolled using the Sb/Bi ratio. Pyrochlore (Zn2Bi3Sb3O14), α-spinel (Zn7Sb2O12), and δ-Bi2O3 (also β-Bi2O3 at Sb/Bi≤1.0)were detected for all of the systems. Mn and Cr are involved in the development of each phase. Pyrochlore was decomposedand promoted densification at lower temperature on heating in Sb/Bi=1.0 system by Mn rather than Cr doping. A morehomogeneous microstructure was obtained in all systems affected by α-spinel. In ZBS(MnCr), the varistor characteristics wereimproved dramatically (non-linear coefficient, α=40~78), and seemed to form Vo.(0.33eV) as a dominant defect. Fromimpedance and modulus spectroscopy, the grain boundaries can be seen to have divided into two types, i.e. one is tentativelyassigned to ZnO/Bi2O3 (Mn,Cr)/ZnO (0.64~1.1eV) and the other is assigned to the ZnO/ZnO (1.0~1.3eV) homojunction.