• Journal of Energy Engineering
• /
• v.26 no.3
• /
• pp.97-104
• /
• 2017

In this study, waste tire rubbers were pyrolyzed in a lab-scale pyrolysis plant equipped with a fluidized bed reactor in a temperature ranges of $450-650^{\circ}C$. The main object of this work is to investigate the properties of pyrolysis oil with reaction temperatures and the behavior of sulfur in the products when waste polypropylene was added for co-pyrolysis. The maximum yield of oil was about 52wt.% at the reaction temperature of $456^{\circ}C$. From GC-MS analysis, the pyrolysis oils consisted mainly of limonene, toluene, xylene, styrene, trimethylbenzene, methylnaphthalenes and some heteroatom(sulfur and nitrogen)-containing compounds. The addition of waste polypropylene resulted in decrease in sulfur contents of the pyrolysis oils.

• Journal of KIISE:Databases
• /
• v.28 no.3
• /
• pp.344-356
• /
• 2001

This paper deals with the subsequence searching problem under time-warping in sequence databases. Our work is motivated by the observation that subsequence searches slow down quadratically as the average length of data sequences increases. To resolve this problem, the Segment-Based Approach for Subsequence Searches (SBSS) is proposed. The SBASS divides data and query sequences into a series of segments, and retrieves all data subsequences that satisfy the two conditions: (1) the number of segments is the same as the number of segments in a query sequence, and (2) the distance of every segment pair is less than or equal to a tolerance. Our segmentation scheme allows segments to have different lengths; thus we employ the time warping distance as a similarity measure for each segment pair. For efficient retrieval of similar subsequences, we extract feature vectors from all data segments exploiting their monotonically changing properties, and build a spatial index using feature vectors. Using this index, queries are processed with the four steps: (1) R-tree filtering, (2) feature filtering, (3) successor filtering, and (4) post-processing. The effectiveness of our approach is verified through extensive experiments.

• Journal of the Korea Society of Computer and Information
• /
• v.27 no.9
• /
• pp.13-20
• /
• 2022

It's proposed and analyzed ML(Machine Learning) models to predict vehicle FC(Fuel Consumption) in real-time. The test driving was done for a car to measure vehicle speed, acceleration, road gradient and FC for training dataset. The various ML models were trained with feature data of speed, acceleration and road-gradient for target FC. There are two kind of ML models and one is regression type of linear regression and k-nearest neighbors regression and the other is classification type of k-nearest neighbors classifier, logistic regression, decision tree, random forest and gradient boosting in the study. The prediction accuracy is low in range of 0.5 ~ 0.6 for real-time FC and the classification type is more accurate than the regression ones. The prediction error for total FC has very low value of about 0.2 ~ 2.0% and regression models are more accurate than classification ones. It's for the coefficient of determination (R²) of accuracy score distributing predicted values along mean of targets as the coefficient decreases. Therefore regression models are good for total FC and classification ones are proper for real-time FC prediction.

• Polymer(Korea)
• /
• v.28 no.1
• /
• pp.3-9
• /
• 2004

Silane modified perfluoropolyethers (SPFPE) was synthesized as a self-assembled mono-layers (SAMs) thin film for micro-electro mechanical system (MEMS). SPFPE was compared to the Perfluoropolyethers (PFPE) as well as octadecyltrichlorosilane (OTS) and perfluorooctyltrichlorosilane (FOTS) with respect to the development of hydrophobicity in the SAMs surface. SPFPE shows less hydrophobicity than those of OTS and FOTS. Thermal annealing of SPFPE SAMs resulted in the enhancement of hydrophobicity as much as those of OTS and FOTS. The SAMs formed from SPFPE were found to be similar as OTS and FOTS SAMs with smooth R$\sub$a/ values of 0.3 nm. However, the flexible chain mobility of SPFPE resulted in 50% reduction as much as the fiction force in OTS.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.19 no.6
• /
• pp.29-35
• /
• 2020

Transition Nozzles are used in industrial air-cooled heat exchangers and widely used in industrial sites as an important component in the heat energy transfer between a heat source and an actuating fluid. There is a worldwide demand for transition nozzles with various materials and shapes, depending on the use environment. This paper aims to improve the transition nozzle forging process suitable for the production of many varieties using Steps 1 to 6 of the TRIZ Methodology for Problem Solving. By utilizing the TRIZ Methodology, this study derives a method to design a variable mold, which is more efficient and can reduce costs compared with having to use several molds. To verify the suitability of the methods derived using the TRIZ technique, a forging analysis is performed on a transition nozzle using DEFORMⓇ, a commercial program for plasticity analysis, and the nozzle material is evaluated for damage as a result of deformation of the transition nozzle thickness. The derived methods can be applied to transition nozzle formation equipment to improve the efficiency of the formation process.

• Proceedings of the Korea Society for Industrial Systems Conference
• /
• 2009.05a
• /
• pp.173-176
• /
• 2009

국가 과학기술 경쟁력 재고를 위하여 R&D기관에서 생성되는 연구데이터를 종합적으로 관리하고 서비스하는 데이터 관리/서비스 시스템의 개발의 필요성이 증대되고 있다. 이에 따라 본 연구에서는 VKH (Visible Korean Human) 데이터를 3차원으로 시각화 서비스하는 플랫폼을 제안하고 구현한다. VKH 데이터는 사망과 동시에 급속 냉동한 인간의 신체를 0.2mm 간격으로 절단하며 촬영한 방대한 양의 실사 이미지 데이터베이스이며, 전통적인 생물학, 의학 분야의 연구뿐만 아니라, 현실감 있는 3D 이미지 구축을 위한 기반 데이터로 이용되고 있다. VKH 데이터 기반의 3D 데이터 시각화 플랫폼은 사용자 접근 편의성을 위하여 웹을 기반으로 구현되고, 트리 형식의 인체 구조 온톨로지와 연동하여 해당하는 인체 구성 요소를 체계적으로 관찰하는 기능, 사용자의 원하는 인체 구성 요소들만을 3D 화면에서 조합하고 관찰하는 기능, 위키피디아 백과사전을 참조하는 기능을 포함한다. 현재 인체의 머리 부분 3D 데이터를 대상으로 플랫폼이 구축되고 있으며, 향후 전체 인체를 대상으로 서비스할 예정이다.

• Textile Coloration and Finishing
• /
• v.6 no.2
• /
• pp.30-39
• /
• 1994

To study the printing behaviors of Polyester and cotton(P/C) fabrics printed with disperse and reactive dyes, the effects of alkalis on the fixation of reactive dyes and the alkali-stability of disperse dyes in various methods of fixation were examined. The anthraquinone disperse dyes which have diamino derivatives as substituents without hydroxy group, such as C.I. Disperse Violet 1(D.V.1), C.I. Disperse Violet 28(D.V.28) and C.I.Disperse Blue 60(D.B.60) showed good results of fixation without regard to the concentration of NaHCO$_3$. In case of high temperature steaming(HTS) and unsaturated steaming(US)/HTS, D.V. 1 was alkali-stable and effective for P/C printing. A good result was obtained with D.V.1 and C.I.Reactive Orange 13(R.O.13) paste of 4% $K_{2}CO_{3}$. It was found that the unfixed D.V.28 bearing chloro group can hinder the fixation of monochlorotriaxinyl reactive dyes, and D.B.60 made little stain on 100% cotton. In thermosol(Tm), the dye uptake of D.V.1 was not decreased so much, but those of D.V.28 and D.B.60 were greatly decreased.

• Journal of Sericultural and Entomological Science
• /
• v.38 no.2
• /
• pp.124-129
• /
• 1996

Oral application of dimethyl sulfoxide in different concentration (1, 3 and 5 percent) to silkworm, Bomyx mori at the fourth and the fifth instar has significantly increased the commercial characters such as larval and silkgland weights, female and male cocoon weights, their shell weights and egg production. However, larval duration, cocooning and hatching percentages did not showed any significant change, as compared with that of the corresponding parameters of the carrier control. Similarly the glycogen and protein contents of the fat body and trehalose and protein contents of the haemolymph were significantly increased in 1 and 3 percent, whereas the increase of them in 5 percent concentration did not take place significantly, except haemolymph trehalose where it was found to be significant, as compared with that of carrier control.

• Magazine of the Korea Concrete Institute
• /
• v.2 no.1
• /
• pp.79-90
• /
• 1990

The purpose of this paper is to study on the effect of cutting off tension bars in reinforced concrete beams. that is, the ultimate strength, the failure mode and thl} tension stress distribution through the span. To achieve this purpose, a full-scale frame and seven small scale model beams (five rectangular and two T-section beams) were tested. The four main model specimens and two speciml}ns without cutting off tension bars 1,'{ere analyzed as plane stmss element with package program ADINA. As a result of test and analysis, the shorter' distance bet ween the reaction point and the cutting off point, the higher the ultimate strength of a bl}am will be when other physical properties are equal.

• Journal of Korea Multimedia Society
• /
• v.13 no.10
• /
• pp.1534-1546
• /
• 2010

In sensor network systems, various hierarchical clustering schemes have been proposed in order to efficiently maintain the energy consumption of sensor nodes. Most of these schemes, however, are hardly applicable in practice since these schemes might produce unbalanced clusters or randomly distributed clusters without taking into account of the distribution of sensor nodes. To overcome the limitations of such hierarchical clustering schemes, we propose a novel scheme called CSM(Clustering using Split & Merge algorithm), which exploits node split and merge algorithm of tree-based indexing structures to efficiently construct clusters. Our extensive performance studies show that the CSM constructs highly balanced clustering in a energy efficient way and achieves higher performance up to 1.6 times than the previous clustering schemes, under various operational conditions.