• 한국표면공학회지
• /
• 제39권6호
• /
• pp.250-254
• /
• 2006

Effect of hydrogen partial pressure ratio on the structural and electrical properties of highly c-axis oriented ZnO films deposited by oxygen ion-assisted pulsed filtered vacuum arc at a room temperature was investigated. The hydrogen partial pressure ratio were $1.4%\sim9.8%$ at 40% oxygen pressure ratio. The conductivity of ZnO:H films was increased from 1.4% up to 4.2% due to relatively high carrier mobility caused by improvement of crystallinity While the conductivity of ZnO:H films were decreased over than 4.2% and (0002) orientation was also deteriorated. The lowest resistivity of ZnO:H films was $2.5{\times}10^{-3}\;{\Omega}{\cdot}cm$ at 4.2% of hydrogen pressure ratio. Transmittance of ZnO:H films in visible range was 85% which is lower than that of undoped ZnO films because of declined preferred orientation.

• 한국자원식물학회:학술대회논문집
• /
• 한국자원식물학회 2018년도 춘계학술발표회
• /
• pp.38-38
• /
• 2018

The genus Carduus (Asteraceae), containing ca. 90 species, is mainly distributed in Eurasia and Africa. Carduus species are one of the most hazardous invasive species, which causes serious environmental threats and biodiversity damages in North America. Thus, the member of Carduus are targeted for classical biological control in this region. Here, we provide the complete cp genome of Carduus crispus using next-generation sequencing technology. The size of cp genomes of C. crispus is 152,342 bp. It shows a typical quadripartite structure, consisting of the large single copy (LSC; 83,254 bp), small single copy (SSC; 18,706 bp), separated by a pair of inverted repeats (IRs; 25,191 bp). It contains 115 unique genes of which 21 genes duplicated in the IR regions. The cpSSR regions of Carduus species were searched through the complete chloroplast genome sequence using a tandem repeat search tool in Geneious with the parameters set to ${\geq}7$ mononucleotide repeats, ${\geq}4$ di- and trinucleotide repeats, and ${\geq}3$ tetra-, penta-, and hexanucleotide repeats. A total of 22 repeat motifs were identified, which may be useful for molecular identification of Korean Carduus species (C. cripus), and providing a guideline for its conservation.

• 건축역사연구
• /
• 제1권1호
• /
• pp.240-254
• /
• 1992

The purpose of this paper is to suggest new direction to the historical research society of Korean architecture by epistemological discussion. Korean architectural history at present, without question of history for what, for whom, and how, is regarded as 'history for the past' only 'to describe past' or 'to collect correct data' However, history is beyond that; history ought to suggest a direction of present and near future. Moreover, architecture is not pure but applied knowledge, that is, focused to 'how to build'. Therefore, past historical knowledge by research should influence to present design. In order to do that, history of mere data collection should change direction to the history of meaning by interpretation, and then, of finding design principle. The principle used in architectural community becomes theory in scientific research community, and finally is unified to 'theory of practice'. Creative history should be substituted for retrospective history reusing historical reservoir, at the specific situation of Korea; tradition has been discontinued drastically and Western method imported to the point of being culturally-colonized. Some expmples of altanative history are suggested at the end of this paper as conclusion.

• 대한인간공학회지
• /
• 제30권3호
• /
• pp.389-394
• /
• 2011

The aims of this study are to investigate the Korean population stereotype for control-display linkage of four-burner gas-range, and to compare the results of this study with those of the existing studies. The investigation used a paper-pencil test using questionnaire with a sign code system for eliminating suggestive effect of sequential code. Two hundreds and eighty subjects participated in the investigation, among whom 254 subjects effectively responded to question for the gas-range stereotype. The results showed that type III(refer to Table 2) was chosen more frequently than type II, IV and V(p<0.01). The gender is not significant on responding rate for the type of control-burner linkage(p>0.92), while the age and occupation have significant effect on the rate(p<0.01). Based on this study, it appears that type III represents the population stereotype of control-burner arrangement for Korean. The stereotype was the same as that of Chinese, but different from that of American(type II or IV). The findings of this study would be helpful as basic data for ergonomically designing gas-range or similar products.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2001년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
• /
• pp.254-257
• /
• 2001

This paper is managing about problem and EMI by electromagnetic waves occurrence of electrical appliances and harmfulness of EMS and standard. Specially, because this paper certifies a mouse and electromagnetic waves interception effect of electricity market place which possess electromagnetic waves interception facility, there is effect that contribute in health life that do to secure safe going to sleep condition from electromagnetic waves of electricity market place that is security of computer working environment of safe state through electromagnetic waves interception and essential electric appliance of home life.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2008년도 제31회 추계학술대회논문집
• /
• pp.251-254
• /
• 2008

하이브리드 로켓엔진의 연소시험을 수행하기 위해 시험 설비를 제작하고 지상연소시험장을 구축하였다. 연소시험장 설비는 하이브리드 로켓엔진, 추력 시험대, 산화제 저장 및 공급 장치, 제어 장치, 데이터 획득 장치로 구성되었다. 추력 50 kgf 급의 연소 시험을 수행하여 안정적으로 성능 데이터를 획득할 수 있었으며, 연소시험장 설비의 작동 신뢰성을 확인하였다.

• Elastomers and Composites
• /
• 제33권4호
• /
• pp.246-254
• /
• 1998

Styrene butadiene rubber (SBR)/ 카렬블랙 복합체의 전기저항 특성과 전기전도 특성을 연구하기 위하여 표면저항, 체적저항, point to point 저항, 정전하 소멸시간 및 전기전도 실험을 4종의 카본블랙을 사용하여 실시하였다. 약 50phr의 카본블랙이 첨가되었을 때, 모든 저항값이 급격히 감소하는 임계영역 (Rc)을 나타내었다. 카본블랙이 첨가된 SBR 복합체의 전류밀도는 전기장의 증가에 따라 증가하며, 기울기 (dJ/dE)가 증가하는 임계점 (Pc)이 존재하였으며, 이때의 전기전도기구는 임계점을 기준으로 하여 낮은 전기장 영역에서는 ohmic 전도, 높은 전기장 영역에서는 공간전하 제한전도임을 알 수 있었다.

• 약학회지
• /
• 제41권4호
• /
• pp.407-413
• /
• 1997

Magnolol and honokiol, the main components of Magnoliae Cortex, were isolated and used as the standard substances for the analysis. In order to determine the contents of magnolol and honokiol in Magnoliae Cortex originated from Korea, China and Japan, both HPLC and HPTLC methods are applied and compared with each other. The components were separated on C8 column with acetonitrile-water-acetic acid (50:50:1) in HPLC and detected at UV 294nm. The components separated on HPTLC precoated silica gel plate with chloroform-methanol (9:1) were detected directly on the plate at 254nm. The contents of magnolol and honokiol in Magnoliae Cortex were in the wide range of 0.01~2.8% and 0.005~0.8%, respectively, according to their purchase places. It is also applicable to the quality control of various preparation from Magnoliae Cortex.

• 한국재료학회지
• /
• 제31권5호
• /
• pp.245-254
• /
• 2021

Wire arc additive manufacturing (WAAM) is being considered as a technology to replace the conventional manufacturing process of titanium alloys. However, coarse β grains, which can extend through several deposited materials, result in strong textures and anisotropy. As a solution, we study the plastic deformation effects of ultrasonic needle peening (UNP) on the microstructure. UNP treated materials deform plastically and the dislocation density increases. Fine α+α' grains with low aspect ratio are observed in the UNP treated specimens. UNP treated WAAM Ti-6Al-4V alloys have higher strength and lower elongation than those characteristics of WAAM Ti-6Al-4V alloys. Due to UNP treatment, the z-axis directional specimens exhibit a greater effect of reducing elongation than do the x-axis directional specimens. The UNP treatment produces fine grains in proportion to the number of times UNP is performed, thereby increasing strength. UNP processes produce a large number of dislocations in the WAAM Ti-6Al-4V alloys, with the most dislocations being formed at the surface.

• 대한의용생체공학회:의공학회지
• /
• 제44권4호
• /
• pp.242-254
• /
• 2023

Although upper respiratory tract infections (URTIs) are common diseases, there have been no studies of their relationship with the indices obtained from tongue image analyses. The purpose of this study was to identify a tongue index through an analysis of tongue images (TIs) showing significant changes before and after treatment in patients with URTIs. A computerized tongue image acquisition system was developed to acquire TIs from subjects in the same environment. An image was taken from each of 39 URTI patients and 39 healthy controls. For the patients, images were acquired before and after treatment to identify changes. The tongue area was classified into a tongue body and a tongue coating, and the coating ratio between the two areas, the average value of the colour of each area, and teeth marks were calculated. No significant difference was observed in age or sex between the URTI patients and control participants. Heart rates were slightly different. The analysis of TIs showed that the luminance of the tongue coating and the coating area ratio were decreased, while the reddish value of the tongue body at the centre area increased as the treatment progressed. Tongue coating and body in URTIs had different colour and shape from those in the normal. It is expected that this result will contribute not only to the objectification of traditional Chinese medicine but also to diagnostic methods that do not involve face-to-face physician visit during the pandemic.