정하중열싸이클법을 이용한 Ti-Ni 계 형상기억합금의 형상회복응력 연구

하광수,남태현,노정필 대한금속재료학회(대한금속학회) 1996 대한금속·재료학회지 Vol.34 No.9

Shape recovery stress of Ti-50.2Ni and Ti-(50-X)Ni-XCu(at%)(X=5-30) shape memory alloys has been measured by means of thermal cycling tests under constant load. In each alloy, the shape recovery stress increased with increasing applied stress up to the critical stress for slip deformation, above which it decreased with increasing applied stress. This was due to decrease in recoverable elongation by the slip deformation. The critical stress for slip deformation depended on Cu-content. With respect to the maximum shape recovery stress, for the alloys whose Cu-content was less than 5at% and more than 15at%, it decreased with increasing Cu-content. For the alloys whose Cu-content was between 5at% and 15at%, however, it increased with increasing Cu-content. Cu-content dependence of the maximum recovery force did not correspond to that of recoverable elongation. Thermal cycling test under costant load method was effective to measure a heating temperature dependence of the shape recovery stress.

가막만해역 패류의 세균학적·독물학적 안전성 평가

하광수,신순범,이가정,정상현,오은경,이희정,김동욱,김연계 한국식품위생안전성학회 2017 한국식품위생안전성학회지 Vol.32 No.6

To evaluate bacteriological and toxicological safety, the hygienic indicator bacterium and paralytic and diarrhetic shellfish toxins in the shellfish produced in the Kamakman Area from 2012 to 2016 were investigated. Fecal coliforms and E. coli of all 194 oyster samples tested did not exceed 230 MPN/100 g. The geometric mean of the fecal coliform analyzed with the oyster samples of harvesting period was 19.6 MPN/100 g, which was more stable than the non-harvesting period (26.5 MPN/100 g). For the toxicological evaluation of the Kamakman Area, 77 oyster samples and 350 mussel samples as an indicator were analyzed. Paralytic shellfish toxins were detected very low in the range of 40~46 μg/100 g in 13 mussel samples during late April and early June, but not in oyster samples. Diarrhetic shellfish toxin was detected in 2 of 180 samples, but it was found to be below the regulation value (0.16 mg OA equ./kg). Based on the bacteriological studies, it was confirmed that the shellfish produced in Kamakman area meets the standard of shellfish hygiene of the Food Sanitation Act and meets the Grade A of the shellfish production area of EU. As the results of the paralytic and diarrhetic shellfish toxin evaluation, it was confirmed that the Kamakman Area is also toxicologically safe for shellfish production.

디지털과 아날로그 콘텐츠 융합을 통한 어린이 그림책 만들기 활동방법

하광수 한국콘텐츠학회 2020 한국콘텐츠학회논문지 Vol.20 No.2

Advancements in digital technology have caused significant changes to the tradition of creative educational activities. Such an with digital technology is prone to an error where digital technology itself becomes the goal, ignoring educational efficacy grounded on improved user experience and immersion. Previously, picture book-making activities for children allow them to actively participate in the process of book-making, and is often employed to instill reading habits as well as nurture linguistic abilities. Aside from such picture book-making activities, diverse efforts are being made for innovation in educational pedagogy through digital technology. However, as the goal of children’s picture book-making activities is realizing creative education through expressions in language and pictures, digital technology should be considered in the viewpoint of fusion, not as a simple replacement to the traditional tools employed in children’s picture book-making activities. This study examines previous researches related to children’s picture book-making activities to propose contents and methodology allowing effective immersion by fusing digital technology based on a physical environment, from the viewpoint of fusion and integration. Expect this study will become a fundamental data in visualizing a practical integration of digital technology in future creative education. 디지털기술의 발달은 창의 교육 활동의 전통에 큰 변화를 주고 있다. 그러나 디지털 중심의 맹목적 접근은 사용자 경험(UX)의 증대와 몰입을 기반으로 한 교육 효과를 외면한 채 디지털기술 그 자체가 목적이 되는 오류를 범하기 쉬울 것이다. 그간 교육현장에서 어린이 그림책 만들기 활동은 어린이 스스로 책을 만드는 과정에 적극적으로 참여함으로써 책 읽는 습관과 함께 언어능력을 발달시키는 데 도움을 주는 활동으로 즐겨 사용되었다. 이런 어린이 그림책 만들기 활동을 통한 교육에도 디지털기술을 이용한 교육방법의 변화와 혁신이 다양하게 시도되고 있다. 그러나 어린이 그림책 만들기 활동의 목적은 언어와 그림 표현을 통해 창의적 교육을 실현하기 위한 것으로, 디지털기술은 전통적 방식의 어린이 그림책 만들기 활동을 위한 도구의 단순한 대체가 아닌 융합의 관점에서 검토되어야 할 것이다. 본 연구에서는 어린이 그림책 만들기 활동과 관련한 그간의 연구를 분석하고, 이를 기반으로 융합적이며 통합적인 관점에서 효과적 몰입을 끌어낼 수 있는 어린이 그림책 만들기 콘텐츠와 활동방법을 제안하였다. 본 연구를 통해 기존 교육방식과 디지털기술을 효과적으로 융합하는 사용자 경험을 제안함으로써 앞으로의 창의 교육 현장에서 디지털기술의 실질적 융합을 가시화시킬 수 있게 되는 기초자료가 될 수 있을 것으로 기대된다.

자란만·사량도해역 패류에 대한 위생학적 안전성평가

하광수,권지영,정상현,박큰바위,김동욱,이가정,정연중,목종수,손광태 한국패류학회 2020 The Korean Journal of Malacology Vol.36 No.4

To evaluate bacteriological and toxicological safety, the hygienic indicator bacteria and paralytic shellfish toxins in the shellfish produced in the Jaranman·Saryangdo area from 2016 to 2018 were investigated. The bacteriological quality of oysters collected from Jaranman·Saryangdo area meets the standard value based on shellfish hygiene of the Food Sanitation Act of Korea and the Grade A according to the classification of shellfish harvesting areas of European Union, respectively. Paralytic shellfish toxins in mussel samples collected from March to April in 2018 were detected as the range of 0.82-15.26 mg/kg, which was significantly exceeding the standard value. Paralytic shellfish toxins in oyster samples collected from the middle of April in 2018 were also showed as the range of 0.93-3.39 mg/kg. As concerns over the spread and high concentration of marine biotoxins due to recent climate change, the improvement of monitoring and safety management for shellfish toxins are consistently required.

Complete genome sequence of Bacillus velezensis SRCM102755, a high menaquinone-7 producer, isolated from Doenjang

하광수,임수아,신수진,류민지,김진원,정성엽,정도연 한국미생물학회 2020 미생물학회지 Vol.56 No.1

Bacillus velezensis SRCM102755, isolated from Doenjang was screened as a starter for Cheonggukjang containing high menaquinone-7 (MK-7) production. Here, we report the complete genome sequence of B. velezensis SRCM102755. The complete genome was sequenced by Pacific Biosciences (PacBio) singlemolecule real-time (SMRT) RS II platform. The genome consists of a single, circular chromosome of 4,044,843 base pairs with a G + C content of 46.34%, and included 3,856 protein coding genes and 113 RNA genes (27 rRNA genes, 86 tRNA genes). The genome was identified to contain at least of nine genes involved in MK-7 biosynthesis.

경남 한산·거제만해역에서 생산된 패류의 위생학적 안전성 평가

하광수,이가정,정연중,목종수,김풍호,김연계,이희정,김동욱,손광태,Ha, Kwang-Soo,Lee, Ka-Jeong,Jeong, Yeon-Jung,Mok, Jong-Soo,Kim, Poong-Ho,Kim, Yeon-Kye,Lee, Hee-Jung,Kim, Dong-Wook,Son, Kwang-Tae 한국식품위생안전성학회 2018 한국식품위생안전성학회지 Vol.33 No.5

본 연구는 2013년부터 2017년까지 경남 한산 거제만 해역에서 생산되는 패류에 대한 위생지표세균, 마비성 패류독소, 설사성 패류독소를 분석하여 세균학적 독물학적 안전성을 평가하였다. 굴 시료 404점에 대한 분변계대장균은 < 18~330 MPN/100 g의 범위를 나타내었으나, 대장균 230 E. coli MPN/100 g을 초과한 시료는 없었다. 굴 수확시기 동안 분석한 대장균의 기하학적 평균치는 24.3 MPN/100 g으로 매우 낮게 나타났다. 한산 거제만해역에서 생산되는 굴의 세균학적 안전성을 평가한 결과, 식품위생법의 생식용 굴에 대한 위생기준을 만족하였고, EU의 패류생산해역 A등급 기준에 부합하였다. 한산 거제만해역의 독물학적 평가를 위해 굴 532개 시료와 패류독소 지표종인 지중해담치 268개 시료에 대한 분석을 실시하였다. 마비성패류독소는 2013년 4월에 지중해담치 3개 시료에서 1.20~2.29 mg/kg 범위로 기준을 초과하여 검출되었으나, 굴시료에서는 전혀 검출되지 않았다. 총 120개 시료에서 설사성패류독소를 분석하였으나, 정량한계 이하로 매우 낮게 나타났다. 독물학적 안전성 평가결과, 굴 시료에서는 마비성 및 설사성패류독소가 전혀 검출되지 않았으나, 지표종인 지중해담치에서는 마비성패류독소 기준치를 초과한 것으로 나타나 지속적인 모니터링과 안전관리가 요구되었다. To evaluate bacteriological and toxicological safety hygienic indicator bacterium and paralytic and diarrhetic shellfish toxins in the shellfish produced in Hansan Geojeman 2013-2017 were investigated. Fecal coliforms were < 18~330 MPN/100 g in 404 oyster samples. But all samples tested, did not exceed 230 E. coli MPN/100 g. Geometric mean of E. coli for oyster samples collected during major shellfish production period was 24.3 MPN/100 g, considerde stable results. Bacteriological quality of oysters collected from Hansan Geojeman meets the standard value based on shellfish hygiene of the Food Sanitation Act of Korea and also meets Grade A, according to classification of shellfish harvesting areas of the European Union. For toxicological evaluation of Hansan Geojeman, 532 oyster samples and 268 mussel samples as an indicator, were analyzed. Paralytic shellfish toxins were detected in the range of 0.42~2.29 mg/kg in eight mussel samples, and exceeded criteria in three samples from early to late April 2013. Diarrhetic shellfish toxin was detected in three of 120 samples, but it was revealed to be under regulation value (0.16 mg Okadaic Acid equ./kg). As a result of toxicological evaluation, paralytic and diarrhetic shellfish toxins were not detected in oyster samples, but it was found that mussel as an indicator species, exceeded the threshold value of paralytic shellfish toxin. Accordingly, sanitary surveys were continuously requested for food safety management of shellfish.

1,5,9,13-Tetrathiacyclohexadecane 수식전극을 사용한 Ag(I)의 전기화학적 정량

하광수,장미경,서무룡,Ha, Kwang Soo,Jang, Mi-Kyeong,Seo, Moo Lyong 한국분석과학회 1997 분석과학 Vol.10 No.3

[16]-ane-$S_4$/탄소분말 함량비를 50%로 하여 nujol oil과 혼합하여 수식전극을 제조하였다. $5.0{\times}10^{-4}M$ $Ag^+$를 포함하는 pH 4.5인 아세트 완충용액에 수식전극을 담가 $Ag^+$를 전극 표면에 흡착시켰다. 이 때 흡착시간을 15분으로 하고 전해환원시키는 시간은 -0.3V vs S.C.E에서 2분으로 하였다. 또한 0.1M $HNO_3$ 용액으로 전극을 활성화시켰으며 한번 활성화한 전극은 10회까지 사용이 가능하였다. 최적 분석조건에서 미분펄스 전압전류법으로 $5.0{\times}10^{-7}{\sim}1.5{\times}10^{-6}M$ 사이의 농도 범위에서 정량해 보았을 때 직선성이 잘 성립하였으며, 검출한계는 $2.0{\times}10^{-7}M$이었다. 대부분의 금속들은 방해를 주지 않았으나, Cu(II)은 방해를 나타내었다. Chemically modified electrodes(CMEs) for Ag(I) were constructed by incoporating 1,5,9,13-tetrathiacyclohexadecane([16]-ane-$S_4$) with a conventional carbon-paste mixture composed of graphite powder and nujol oil. Ag(I) ion was chemically deposited onto the surface of the modified electrode with [16]-ane-$S_4$ by immersion of the electrode in the acetate buffer solution(pH=4.5) containing $5.0{\times}10^{-4}M$ Ag(I) ion. And then the electrode deposited with Ag(I) was reduced at -0.3V vs. S.C.E. Well-defined stripping voltammetric peaks could be obtained by scanning the potential to the positive direction. The CME surface was regenerated with exposure to 0.1M $HNO_3$ solution and was reused for the determination of Ag(I) ion. When deposition/measurement/regeneration cycles were 10 times, the response could be reproduced with relative standard deviation of 6.08%. In case of differential pulse stripping voltammetry, the calibration curve for Ag(I) was linear over the range of $5.0{\times}10^{-7}{\sim}1.5{\times}10^{-6}M$. And the detection limit was $2.0{\times}10^{-7}M$. Various ions such as Cd(II), Ni(II), Pb(II), Zn(II), Mn(II), Mg(II), EDTA, and oxalate(II) did not influence the determination of Ag(I) ion, except Cu(II) ion.

음성 UX 프로토타이핑 기법과 오즈의 마법사 평가 방법을 활용한 음성 UX 디자인

하광수 한국콘텐츠학회 2023 한국콘텐츠학회논문지 Vol.23 No.5

Recently, voice UX has been expanding very rapidly and has taken place as a familiar interaction method to users. Nevertheless, voice UX has received numerous requests for improvement due to the weak user experience compared to the speed of spread. In order to solve the usability problem of voice UX, it is essential to change the method and process of designing voice interface and interaction that can support repeated evaluation and modification of voice UX. However, a voice UX design method that easily supports iterative evaluation and revision in voice UX design has not been developed yet. If a design tool familiar to UX designers can be used for voice interface prototyping in this research, it may become a reasonable and economical choice for UX designers. We proposed a method of designing a voice UX as a prototype by visualizing the voice interface and interaction through the Adobe XD program, which is a relatively familiar tool for UX designers. In addition, the proposed voice UX prototype was extended to the usability evaluation method so that it can be verified through the Wizard of Oz technique. Lastly, the usefulness of the proposed voice UX design method was verified by applying it to the process of developing a smart speaker for OPIc test learning, which is an English oral proficiency test. It is expected that the voice UX design method proposed through this research can overcome the high cost incurred in terms of time, technology, and expertise required to build a prototype in the voice UX design process and be effectively used in the voice UX design field. Furthermore, it is expected to be utilized in various voice UX design processes to help secure the usability of voice UX. 최근 음성 UX는 매우 빠른 속도로 확장되어 사용자에게 익숙한 인터랙션 방법으로 자리를 잡았다. 그런데도 음성 UX는 확산 속도에 비해 취약한 사용자 경험으로 인해 개선을 요구받고 있다. 이런 음성 UX의 사용성 문제를 해결하기 위해서는 음성 UX의 반복적인 평가와 수정을 지원할 수 있는 음성 인터페이스와 인터랙션을 디자인하는 방법과 프로세스의 변화가 필수적이다. 그러나 아직 음성 UX 디자인에서 반복적 평가와 수정을 손쉽게 지원하는 음성 UX 디자인 방법이 뚜렷하게 나타나지 않고 있다. 본 연구에서는 UX 디자이너에게 익숙한 디자인 도구를 음성 인터페이스 프로토타이핑을 위해 이용할 수 있다면 UX 디자이너에게 합리적이고 경제적인 선택이 될 수 있을 것으로 보았다. 이에 UX 디자이너에게 비교적 친숙한 도구인 Adobe XD 프로그램을 통해 음성 인터페이스와 인터랙션을 시각화해 음성 UX를 프로토타입으로 디자인하는 방법을 제안하였다. 또한 제안된 음성 UX 프로토타입을 오즈의 마법사 기법을 통해 검증할 수 있도록 사용성 평가 방법까지 확장하여 제안하였다. 마지막으로 이렇게 제안된 음성 UX 디자인 방법을 영어 회화 평가인 OPIc 테스트 학습을 위한 스마트 스피커를 개발하는 과정에 적용함으로써 제안된 음성 UX 디자인 방법의 유용성을 검증하였다. 본 연구를 통해 제안된 음성 UX 디자인 방법이 음성 UX 디자인 과정에서 프로토타입을 구축하는 데 필요한 시간과 기술, 전문성 측면에서 발생하는 높은 비용을 극복하고 음성 UX 디자인 현장에서 효과적으로 사용할 수 있기를 기대한다. 또한 다양한 음성 UX 디자인 과정에서 활용되어 음성 UX의 사용성을 확보하는 데 도움이 되길 기대한다.

경남 진해만해역의 마비성패류독소 모니터링 빈도에 대한 위해성평가

하광수,이가정,손광태,김지회,김풍호,김연계,김영목,노맹석,이태식 한국수산과학회 양식분과 2017 한국수산과학회 양식분과 학술대회 Vol.2017 No.5

가공열처리한 Ti-Ni-Cu 형상기억합금의 형상회복응력

하광수,남태현,조규봉,허신구 대한금속재료학회(대한금속학회) 1997 대한금속·재료학회지 Vol.35 No.3

Shape recovery stress of thermo-mechanically treated Ti-Ni and Ti-Ni-Cu shape memory alloys has been investigated by means of thermal cycling test under constant load and also and effect of thermo-mechanical treatment on transformation behaviour and transformation temperatures has been examined by means of electrical resistivity measurements, differential scanning calorimetry and X-ray diffraction. Transformation behaviour was not changed by thermo-mechanical treatments in Ti-Ni-Cu alloys, while it changed from B2(cubic)-B19'(monoclinic) to B2-R(rhombohedral)-B19' in the Ti-Ni alloy. Martensitic transformation start temperature increased silghtly by thermo-mechanical treatments in Ti-Ni-Cu alloys, while it decreased largely in the Ti-Ni alloy. Shape recovery stress of Ti-Ni-Cu alloys was larger than that of the Ti-Ni alloy. This was attributed to the fact that the maximum recoverable elongation of Ti-Ni-Cu alloys was larger than that of the Ti-Ni alloy. And also shape recovery stress depended of Cu-content. It increased from 290MPa to 400MPa with increasing Cu-content up to 5at%, and then decreased from 400MPa to 375MPa with increasing Cu-content from 5at% to 10at%.