• Title/Summary/Keyword: Point LED

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A Study on the Concept Recognition Possibility of Ecorefugee

  • Park, Jong-Ryeol;Noe, Sang-Ouk
    • Journal of the Korea Society of Computer and Information
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    • v.21 no.5
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    • pp.177-184
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    • 2016
  • Since 1980s, 30 years has passed after issues on environmental refugee began to appear. However, why environmental refugee is not considered as refugee officially in international society? Above all, it seems that main point is the responsibility given to those developed countries if they, whom led the climate changes, officially acknowledge environmental refugee. The problem is that environmental refugee has no direct responsibility for causing climate changes. Actually. the responsibility should be granted to the developed and industrialized countries which caused climate changes. In accordance to the refugee protection system established under current international law, it is difficult to include them into refugee category and thus, they can hardly have enough support. It is urgently needed that new refugee treat which have the new standard and solution added to it shall be adopted. To allow new refugee treat to be effective it is compulsory to have constant and binding policy determination and willingness of execution from a united international organization. Of course, before this, countries should try to have common recognition on recognizing new refugee problem and its seriousness as well as solving those problems together. In reality, it is worth considering adoption of semi-forceable type of system as a more effective way, which allocates responsibility of accepting refugee by amount of carbon emitted. Also, as refugee issue has an important influence on mother company and the third countries, execution process of the system has to be defined clearly. For those permanent organizations, they should accurately define environmental factors making refugee and set standards to minimize possibility of abuse and misuse.

An Efficiency Improvement of the OLEDs due to the Thickness Variation on Hole-Injection Materials (정공주입물질 두께 변화에 따른 유기발광다이오드의 효율 개선)

  • Shin, Jong-Yeol;Guo, Yi-Wei;Kim, Tae-Wan;Hong, Jin-Woong
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.28 no.5
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    • pp.344-349
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    • 2015
  • A new information society of late has arrived by the rapid development of various information & communications technologies. Accordingly, mobile devices which are light and thin, easy and convenient to carry on the market. Also, the requirements for the larger television sets such as fast response speed, low-cost electric power, wider visual angle display are sufficiently satisfied. The currently most widely studied display material, the Organic Light-emitting Diodes(OLEDs) overwhelms the Liquid Crystal Display(LCD), the main occupier of the market. This new material features a response speed of more than a thousand times faster, no need of backlight, a low driving voltage, and no limit of view angle. And the OLEDs has high luminance efficiency and excellent durability and environment resistance, quite different from the inorganic LED light source. The OLEDs with simple device structure and easy produce can be manufactured in various shapes such as a point light source, a linear light source, a surface light source. This will surely dominate the market for the next generation lighting and display device. The new display utilizes not the glass substrate but the plastic one, resulting in the thin and flexible substrate that can be curved and flattened out as needed. In this paper, OLEDs device was produced by changing thickness of Teflon-AF of hole injection material layer. And as for the electrical properties, the four layer device of ITO/TPD/$Alq_3$/BCP/LiF/Al and the five layer device of ITO/Teflon AF/TPD/$Alq_3$/BCP/Lif/Al were studied experimentally.

Synthesis and Solution Properties of Zwitterionic Copolymer of Acrylamide with 3-[(2-Acrylamido)dimethylammonio]propanesulfonate

  • Xiao, Hui;Hu, Jing;Jin, Shuailin;Li, Rui Hai
    • Bulletin of the Korean Chemical Society
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    • v.34 no.9
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    • pp.2616-2622
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    • 2013
  • A novel zwitterionic monomer 3-[(2-acrylamido)dimethylammonio]propanesulfonate (DMADAS) was designed and synthesized in this study. Then it was polymerized with acrylamide (AM) by free radical polymerization in 0.5 mol/L NaCl solution with ammonium persulfate ($(NH_4)_2S_2O_8$) and sodium sulfate ($NaHSO_3$) as initiator. The structure and composition of DMADAS and acrylamide-3-[(2-acrylamido)-dimethylammonio]propanesulfonate copolymer (P-AM-DMADAS) were characterized by FT-IR spectroscopy, $^1H$ NMR and elemental analyses. Isoelectric point (IEP) of P-AM-DMADAS was tested by nanoparticle size and potential analyzer. Solution properties of copolymer were studied by reduced viscosity. Antipolyelectrolyte behavior was observed and was found to be enhanced with increasing DMADAS content in copolymer. The results showed that the viscosity of P-AM-DMADAS is 5.472 dl/g in pure water. Electrolyte was added, which weakened the mutual attraction between sulfonic acid group and quaternary ammonium group. The conformation became loose, which led to the increase of reduced viscosity. The ability of monovalent and divalent cation influencing the viscosity of zwitterionic copolymer obeyed the following sequence: $Li^+$ < $Na^+$ < $K^+$, $Mg^{2+}$ < $Ca^{2+}$ < $Ba^{2+}$, and that of anion is in the order: $Cl^-$ < $Br^-$ < $I^-$, $CO{_3}^{2-}$ > $SO{_3}^{2-}{\approx}SO{_4}^{2-}$.

Three Cases with the Multiple Occurrences of Freezing Rain in One Day in Korea (12 January 2006; 11 January 2008; and 22 February 2009)

  • Park, Chang-Kyun;Byun, Hi-Ryong
    • Atmosphere
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    • v.25 no.1
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    • pp.31-49
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    • 2015
  • From the hourly data of 75 Korean weather stations over a 12-year period (2001~2012), this study has chosen three cases (January 12, 2006; January 11, 2008; and February 22, 2009) of multiple freezing rains and investigated the atmospheric circulations that seemed to cause the events. As a result, the receding high pressure type (2006), prevailing high pressure type (2008), and warm front type (2009) are confirmed as synoptic patterns. In all three cases, freezing rain was found in regions with a strong ascending current near the end point of a low-level jet that carried the warm humid air from low latitudes. The strong ascending current resulted from lower-level convergence and upper-level divergence. In 2006 and 2009, the melting process was confirmed. In 2008, the supercooled warm rain process (SWRP) was confirmed. In contrast to existing SWRP theory, it was found that the cool air produced at the middle atmosphere and near the earth's surface led to the formation of freezing rain. The sources of this cool air were supposed to be the evaporative latent heat and the cold advection coming from the northeast. On the other hand, a special case was detected, in which the freezing rain occurred when both the soil surface temperature and surface air temperature were above $0^{\circ}C$. The thickness distributions related to freezing rain in Korea were found to be similar to those in North America. A P-type nomogram was considered for freezing rain forecasting; however, it was not relevant enough to Korea, and few modifications were needed.

Indoor Surveillance Camera based Human Centric Lighting Control for Smart Building Lighting Management

  • Yoon, Sung Hoon;Lee, Kil Soo;Cha, Jae Sang;Mariappan, Vinayagam;Lee, Min Woo;Woo, Deok Gun;Kim, Jeong Uk
    • International Journal of Advanced Culture Technology
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    • v.8 no.1
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    • pp.207-212
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    • 2020
  • The human centric lighting (HCL) control is a major focus point of the smart lighting system design to provide energy efficient and people mood rhythmic motivation lighting in smart buildings. This paper proposes the HCL control using indoor surveillance camera to improve the human motivation and well-beings in the indoor environments like residential and industrial buildings. In this proposed approach, the indoor surveillance camera video streams are used to predict the day lights and occupancy, occupancy specific emotional features predictions using the advanced computer vision techniques, and this human centric features are transmitted to the smart building light management system. The smart building light management system connected with internet of things (IoT) featured lighting devices and controls the light illumination of the objective human specific lighting devices. The proposed concept experimental model implemented using RGB LED lighting devices connected with IoT features open-source controller in the network along with networked video surveillance solution. The experiment results are verified with custom made automatic lighting control demon application integrated with OpenCV framework based computer vision methods to predict the human centric features and based on the estimated features the lighting illumination level and colors are controlled automatically. The experiment results received from the demon system are analyzed and used for the real-time development of a lighting system control strategy.

Effects of the EGR and Injection Pressure on the Combustion and Emission Characteristics of DME Commonrail Diesel Engine (DME를 연료로 하는 커먼레일 디젤 엔진의 연소와 배기 특성에 미치는 분사압력과 EGR의 영향)

  • Chung, Jae-Woo;Kang, Jung-Ho;Lee, Sung-Man;Kim, Hyun-Chul;Kang, Woo
    • Transactions of the Korean Society of Automotive Engineers
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    • v.14 no.4
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    • pp.84-91
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    • 2006
  • In this study, the effect of EGR and fuel injection pressure on the characteristics of combustion and emission performance of the common-rail diesel engine is investigated using DME fuel as a smoke-free alternative fuel. Because the heating value and density of DME fuel are lower than those of diesel fuel, the injection duration of the DME engine is relatively longer than the injection duration of the diesel engine with the same injection pressure. However, the higher injection pressure can shorten the injection duration for the DME engine. Although the smoke level of the DME engine is much lower than that of the diesel engine, the NOx is at a level similar to that of the diesel engine. As a proposed solution for this, the EGR technique is empirically applied to the DME engine. In the experiments, the injection pressure was changed from 200bar to 400bar, and the EGR rate was limited under 40%. With the same injection timing and fuel amount, the experiment results indicated that the increase of injection pressure led to the increase of IMEP while decreasing HC and CO emissions. However, the NOx emission tends to increase as the injection pressure becomes higher. On the other hand, as the EGR rate was increased, NOx emission and A/F were reduced while the HC and CO emissions were increased. Because HC and CO emissions have the critical A/F point where the emissions of HC and CO are rapidly increased, it is proposed that the EGR rate must be limited under the critical EGR rate.

Realistic 3-dimensional using computer graphics Expression of Human illustrations (컴퓨터그래픽스를 이용한 사실적인 3D 인물 일러스트레이션의 표현)

  • Kim, Hoon
    • Archives of design research
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    • v.19 no.1 s.63
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    • pp.79-88
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    • 2006
  • A human face figure is a visual symbol of identity. Each different face per person is a critical information differentiating each person from others and it directly relates to individual identity. When we look back human history, historical change of recognition for a face led to the change of expression and communication media and it in turn caused many changes in expressing a face. However, there has not been no time period when people pay attention to a face more than this time. Technically, the advent of computer graphics opened new turning point in expressing human face figure. Especially, a visual image which can be produced, saved, and transferred in digital has no limitation in time and space, and its importance in communication is getting higher and higher. Among those visual image information, a face image in digital is getting more applications. Therefore, 3d (3-dimensional) expression of a face using computer graphics can be easily produced without any professional techniques, just like assembling puzzle parts composed of the shape of each part ands texture map, etc. This study presents a method with which a general visual designer can effectively express 3d type face by studying each producing step of 3d face expression and by visualizing case study based on the above-mentioned study result.

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Safety countermeasures for the marine casualties of fishing vessels in Korea (우리나라의 어선 해양사고에 대한 안전대책)

  • Kang, Il-Kwon;Kim, Hyung-Seok;Shin, Hyeong-Il;Lee, Yoo-Won;Kim, Jeong-Chang;Jo, Hyo-Jae
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.43 no.2
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    • pp.149-159
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    • 2007
  • Marine casualties of fishing vessels were analyzed to reduce the sacrifice of human life using data of the Korean Maritime Safety Tribunal from 1995 to 2004 in Korea. The occurred number of fishing vessel casualties were likely to be higher portion than non-fishing vessels, but the occurring ratio of fishing vessel casualties were marked 2.96 times lower than that of non-fishing vessel casualties. The occurring ratios of bigger fishing vessel casualties were higher than smaller ones. Most marine casualties were resulted from the human factors such as poor watchkeeping, negligent action for engine and etc. The trend of marine casualties showed that the machinery damage hold the first and collision accidents took the second, but on a point of cause of them, operating errors took first and poor handling or inspection of machinery held the second place. Because those two casualties took major portion, and very important problems for safety of fishing vessels, so we ought to try to reduce the factors before everything else. In addition, since collision, sinking and capsizing in marine casualties have led to death, missing and injury of lives, it is necessary for navigation operators to take more educations and training intended to reduce the marine casualties systematically and continuously.

Feasibility of New Pesticide Development in Korea (우리나라에서의 신농약 개발전망)

  • Park Young-Sun
    • Korean journal of applied entomology
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    • v.22 no.2 s.55
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    • pp.84-97
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    • 1983
  • Under the limited arable land, the enhancement of agricultural productivity is indispensable to provide the food demand which is concomitant with the rapid increase in population. From this viewpoint, the upbringing and dissemination of high-yielding varieties has been promoted continuously and several modifications in cultural practices, including heavy fertilization, dense planting, and early transplanting, also have been gradually developed. However these changes in cultivation have led to the increased outbreak of insect pests and diseases. And this unexpected results have accelerated the number and complexity of pesticides employed as well as their consumption. Even though pesticides are essential materials contributing to the steady production of agricultural crops, large scale consumption of them has given rise to several adverse impacts, such as mammalian hazard and/or environmental contamination. In this respect, recent development of new pesticides has been concentrated on 'safe pesticide', as it were, that has the highly selective properties without unfavorable side influences on other ecosystem. According to literature cited up to now, feasibilities of safe pesticide development would be summarized as two categories. One of them is the development of chemical pesticides, which include the molecular structure modification of established pesticides for increased safety and synthesis of new safe chemicals which can attack the vulnerable point of physio-ecological characteristics in insect pests and diseases. The other is the biological pesticides which comprise natural enemies and microorganisms to act selectively on confined insect pests and diseases, In addition, improvement of physico-chemical properties of available pesticide formulations would be one of the desirable means for safe pesticide development in view of efficacy enhancement and minimization of hazardous properties or safe pesticide development, various approaches are feasible and needed to study, however, long period and much financial outlay are necessary to develop a new item. And under the present situation in Korea, there are many difficulties for performing research on all the possible routes. Therefore, combined pesticides by the reasonable combination of already registered resticides evaluated as the fairly safe pesticides and safe formulation based on their physico-chemical properties would be developed primarily. And many efforts would be given gradually for the development of new chemical and biological pesticides.

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Does matching relation exist between the length and the tilting angle of terminal implants in the all-on-four protocol? stress distributions by 3D finite element analysis

  • Li, Xiaomei;Cao, Zhizhong;Qiu, Xiaoqian;Tang, Zhen;Gong, Lulu;Wang, Dalin
    • The Journal of Advanced Prosthodontics
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    • v.7 no.3
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    • pp.240-248
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    • 2015
  • PURPOSE. To explore whether there is matching relation between the length and the tilting angle of terminal implants in the All-on-Four protocol by studying the effects of different implant configurations on stress distributions of implant, bone, and framework. MATERIALS AND METHODS. Four implants were employed to support a full-arch fixed prosthesis and five three-dimensional finite element models were established with CT images, based on the length (S and L) and distal tilt angle ($0^{\circ}$, $30^{\circ}$ and $45^{\circ}$) of terminal implants for an edentulous mandible, which named: Tilt0-S, Tilt30-S, Tilt30-L, Tilt45-S and Tilt45-L. An oblique 240 N was loaded at second molar. The von Mises Stresses were analyzed. The implants were consecutively named #1 to #4 from the loading point. RESULTS. 1) Tilt0-S had the greatest stress on the implants, with the other groups exhibiting variable reductions; the four implants of Tilt45-L demonstrated the greatest reduction in stress. 2) Tilt0-S had the greatest stress at bone around #1 implant neck, and Tilt45-L exhibited the least stress, which was a 36.3% reduction compared to Tilt0-S. 3) The greatest stress in the framework was found on the cantilevers distal to #1 implant. Tilt45-S exhibited the least stress. CONCLUSION. Matching different length and tilting angle of the terminal implants led to variable stress reductions on implants, bone and the superstructure. By optimizing implant configuration, the reduction of stress on implants and surrounding bone could be maximized. Under the present condition, Tilt45-L was the preferred configuration. Further clinical testings are required.