http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Choi, Woohyuk,Chung, Jae Woo,Kwak, Seung-Yeop American Chemical Society 2014 ACS APPLIED MATERIALS & INTERFACES Vol.6 No.14
<P>We develop a nontoxic unentangled star-shape poly(ε-caprolactone) (UESPCL) plasticizer with excellent migration resistance for the production of phthalate-free flexible poly(vinyl chloride) (PVC) by means of the ring-opening polymerization of ε-caprolactone, initiated from the multifunctional core, combined with end-capping, and vacuum purification processes. UESPCL is a transparent liquid at room temperature and exhibits unentangled Newtonian behavior because of its extremely short branched segments. UESPCL is biologically safe without producing an acute toxicity response. Torque analysis measurements reveals that UESPCL offers a faster fusion rate and a higher miscibility with PVC compared to a typical plasticizer, di(2-ethylhexyl) phthalate (DEHP). The solid-state <SUP>1</SUP>H nuclear magnetic resonance (NMR) spectrum reveals that PVC and UESPCL are miscible with an average domain size of less than 8 nm. The flexibility and transparency of the PVC/UESPCL mixture, that is, phthalate-free flexible PVC, are comparable to the corresponding properties of the PVC/DEHP mixture, and the stretchability and fracture toughness of PVC/UESPCL are superior to the corresponding properties of the PVC/DEHP system. Most of all, PVC/UESPCL shows excellent migration resistance with a weight loss of less than 0.6% in a liquid phase, whereas DEHP migrated out of PVC/DEHP into a liquid phase with a weight loss of about 10%.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2014/aamick.2014.6.issue-14/am500740v/production/images/medium/am-2014-00740v_0008.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am500740v'>ACS Electronic Supporting Info</A></P>
Choi, Hyunjin,Choi, Woohyuk,Lim, Jiseok,Choi, Jungwook Elsevier 2019 Sensors and actuators. A Physical Vol.298 No.-
<P><B>Abstract</B></P> <P>Light-emitting diodes (LEDs) are widely used in many industrial applications owing to their high performance and efficiency compared with conventional lighting systems. However, a considerable amount of input power is inevitably dissipated into heat at the LED junction, which can degrade the performance and reliability of the LED; thus, it is important to monitor the change in the junction temperature of the LED. In this study, we present a micro-temperature sensor-integrated surface-mounted device (SMD) for accurate and real-time measurement of the junction temperature of an LED. The LED is mounted on a microfabricated Pt sensor in a similar way to the typical SMD assembly. The heat generated at the LED junction is conductively transferred to the microsensor, increasing the temperature and changing its electrical resistance. In contrast to the conventional techniques for thermal characterization of LEDs, the integrated microsensor provides real-time information on the junction temperature with high precision, reproducibility, and simplicity. Additionally, the temperature of the solder, which is not easily accessible but is closely related to the reliability of the LED, can be estimated by analyzing the thermal resistance of the LED package. Experimental and numerical results indicate a linear correlation (R<SUP>2</SUP> = 0.988) between the junction and sensor temperatures, which is practically useful for the thermal management of the miniaturized SMD-LED.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Methodology for measuring LED junction temperature is proposed. </LI> <LI> Pt micro-temperature sensor-integrated SMD-LED is designed and fabricated for real-time measurement of junction temperature. </LI> <LI> Highly linear correlation of the temperature between the microsensor and the junction is experimentally found. </LI> <LI> Analysis of structure function, thermal resistance, and numerical calculation of SMD-LED validates measurement accuracy of Pt microsensor. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Choi, Woohyuk,Chung, Jae Woo,Kwak, Seung-Yeop Elsevier 2016 Polymer Vol.103 No.-
<P><B>Abstract</B></P> <P>The dynamic effects of unentangled star-shaped polymers with extremely small branches on the plasticization of miscible polymer blends are investigated using ultra-small branched star poly(<I>ε</I>-caprolactone)s (USB-SPCLs), poly(vinyl chloride) (PVC), and their blends. Photon correlation dynamics of USB-SPCLs supports our previous suggestion that a whole USB-SPCL molecule acts as a single coarse-grain unit with dynamically-equivalent branches because of the extremely small branches, resulting in the total-molecular-weight-dependent Rouse dynamic behaviors of USB-SPCLs, regardless of the molecular architectures. The dynamic light scattering intensity autocorrelation curves of miscible PVC/USB-SPCL blends reveal that strong intermolecular interactions between PVC and USB-SPCL molecules determine the dynamic homogeneous behaviors of the blends despite their significantly different mobilities. The molecular motions of the blends depend on the total-molecular-weight-dependent Rouse dynamic behaviors of USB-SPCLs. These dynamic results clearly show the plasticization of the entangled neat linear PVC matrix by distinctive and rapid molecular mobility of USB-SPCLs.</P> <P><B>Highlights</B></P> <P> <UL> <LI> USB-SPCLs show total-molecular-weight-dependent Rouse dynamic behaviors. </LI> <LI> Dynamic effects of USB-SPCLs on the plasticization of PVC blends are investigated. </LI> <LI> PCS in concentrated systems enables to compare the dynamic changes by blending. </LI> <LI> Dynamic homogeneous behaviors of PVC blends depend on the dynamics of USB-SPCLs. </LI> <LI> PVC matrix is plasticized by distinctive and rapid molecular mobility of USB-SPCLs. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
에디트 슈타인의 신학적 인간학에서 Fiat와 Theotokos의 관계
최우혁(Woohyuk Choi) 한국종교학회 2010 宗敎硏究 Vol.60 No.-
Edith Stein analyzes in her phenomenological analysis the human being as person constituted of body, soul and spirit, and alive to the meantime, according to her female specificity, in the walk toward the truth of Mary completed in her “fiat”. Mary of Nazareth becomes the model of reference for Edith Stein and an example for the humanity. Mary, from the Annunciation up to the Pentecost, as transcendental subject reveals her in the most radical availability to an Other, and in its Truth that becomes mirror of the truth of the man is. In this perspective to know Mary is to know the essence of the human person and her truth to be. In fact the to answer with the “Fiat to the Incarnation of Christ”, that can vary in the different contexts, directs always toward the intelligence of the creature as to be available to the Truth in a meeting and in a transcendental dialogue. Of this ontological truth, Mary is clear mirror, her “fiat”, representative of the human reality, Virgo of the fiat constitutes her, perfect Bride,universal Mother of the Grace. The purpose of the study is this: to want to know Mary in the doctrine of Edith Stein and the Stein and her thought through her doing philosophy with and on Mary. This seems us a new proposal: the “Fiat” of philosophical and of phenomenological becomes the “Fiat” theological of the Trinity,the “Fiat” of her Father, of their Child and of the Spirit to the humanity, event of grace, and it becomes the “fiat” of Mary, and in her life as radical positive answer to the “Fiat”, “Eccomi”,“Yes” of God, event of liberty. A new chapter of the Christian anthropology is born. This article is concerned a new paradigm of the Christian Anthropology through Virgin Mary, Virgo of the “fiat”, reporting herself to the “fiat” to the Truth in her work and thought of Edith Stein.
Hyungsuk Choi,Woohyuk Choi,Tran Minh Quan,Hildebrand, David G. C.,Pfister, Hanspeter,Won-Ki Jeong IEEE 2014 IEEE transactions on visualization and computer gr Vol.20 No.12
<P>As the size of image data from microscopes and telescopes increases, the need for high-throughput processing and visualization of large volumetric data has become more pressing. At the same time, many-core processors and GPU accelerators are commonplace, making high-performance distributed heterogeneous computing systems affordable. However, effectively utilizing GPU clusters is difficult for novice programmers, and even experienced programmers often fail to fully leverage the computing power of new parallel architectures due to their steep learning curve and programming complexity. In this paper, we propose Vivaldi, a new domain-specific language for volume processing and visualization on distributed heterogeneous computing systems. Vivaldi's Python-like grammar and parallel processing abstractions provide flexible programming tools for non-experts to easily write high-performance parallel computing code. Vivaldi provides commonly used functions and numerical operators for customized visualization and high-throughput image processing applications. We demonstrate the performance and usability of Vivaldi on several examples ranging from volume rendering to image segmentation.</P>