• 한국공작기계학회논문집
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• 제13권6호
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• pp.127-134
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• 2004

As the result of reduction of the barrier of national economy on matters of quality assurance of weighing instruments in recently, it is considering in domestic as well as international matters. Therefore, this study is to analysis and compare with international md national measuring standards on the electric self-indicating scale, to improve the quality of electronic machine by providing a reformation plan on currently problems of domestic manufactured, and to identify to introduce in domestic criteria from international standards. I had compared KSC 1313 to OIML R 76-1 as the performance assessment items, such as metrology Properties test, static temperature test, temperature effect testing under the un-load, electronic wave disturbance test, high-tempereature and high-humidity stability test and durability test. Therefore, only one company is passed all items of the test according to the international (reference) standards, but it is possible to improve the quality in general if it should be use the load cell and electric components which is stability of temperature change in order to supplementation to the static temperature test and temperature effect testing under the un-load. It is also possible to apply in the domestic with the OIML 76-1 after correcting the design.

• Journal of Welding and Joining
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• 제29권5호
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• pp.95-98
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• 2011

Recently, there is a growing tendency that fine-pitch electronic devices are increased due to higher density and very large scale integration. Finer pitch printed circuit board(PCB) is to be decrease insulation resistance between circuit patterns and electrical components, which will induce to electrical short in electronic circuit by electrochemical migration when it exposes to long term in high temperature and high humidity. In this research, the effect of soldering flux acting as an electrical carrier between conductors on electrochemical migration was investigated. The PCB pad was coated with OSP finish. Sn3.0Ag0.5Cu solder paste was printed on the PCB circuit and then the coupon was treated by reflow process. Thereby, specimen for ion migration test was fabricated. Electrochemical migration test was conducted under the condition of DC 48 V, $85^{\circ}C$, and 85 % relative humidity. Their life time could be increased about 22% by means of removal of flux. The fundamentals and mechanism of electrochemical migration was discussed depending on the existence of flux residues after reflow process.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1277-1282
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• 2008

Recently LCD panels have becom very important components for portable electronics. In the high density interconnection material, ACF's are used to connect the outer lead of the tape automated bonding to the transparent indium tin oxide electrodes of the LCD panel. ACF consists of an adhesive polymer matrix and randomly dispersed conductive balls. In this study, we analyzed Failure Mode / Mechanism of ACF which is identified Conductive ball Corrsion, Delamination, Crack and Polymer Expansion / Swelling. In ALT(Accelerated Life Test), we select primary stress factors as temperature and humidity. As time passes by, an increase of connection resistance was observed. In conclusion, we have found that high temperature / humidity affects the adhesion.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2004년도 춘계학술대회 논문집
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• pp.392-396
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• 2004

Experimental equipments for long-term outdoor tests of EHV insulators in outdoor were constructed. The testing insulators have been energized with 89 [kV] phase-to-ground AC voltage under identical condition at station, and the investigation was carried out for leakage current and various environments such as temperature, relative humidity and wind velocity. The test results of leakage current wave trends have forms on distorted waves including harmonics. The porcelain and glass insulators have low leakage current in case of daytime because moisture and humidity have relative low values. In comparison with these conditions, high leakage current was shown at dawn and rainy day due to high humidity. However, leakage current of polymer insulators was shown approximately $129[{\mu}m]$ without relation to the weather due to hydrophobicity on their surface.

• 보존과학연구
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• 통권31호
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• pp.59-68
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• 2010

Cultural heritages are damaged by surrounding several environmental factors. Main factors are temperature, humidity, light, atmosphere and indoor pollutant, organism, etc. Therefore, to prevent damage of cultural heritage from such environmental factor, conservation environment monitoring becomes more important. Indicator is one of the simple method for environment monitoring. It can be used without expensive and complex equipments. However, it should be performed scientific examination for application to cultural heritage. In this study, some Temperature Indicators were chosen and reliability assessment was carried out for application to cultural heritage. Brightness($L^*$) is selected for reliability assessment factor. As a result of lab test, Temperature Indicators were not influenced greatly in humidity change. When they were exposed to setting temperature, the color was changed in setting temperature area and ${\pm}2^{\circ}C$ part of setting temperature. Especially brightness value was high in setting temperature area. Also, Temperature Indicators were stabilized after about 16 minutes when were exposed to temperature difference of $10^{\circ}C$ and when temperature difference with exposure environment is smaller, stabilization time shortened. Therefore, it is a possible to confirm that selected Temperature Indicator is reliable product through measurement of color difference value and naked eye observation.

• 에너지공학
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• 제21권3호
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• pp.243-248
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• 2012

본 연구는 고온고습 시험을 통하여 Cell 레벨에서의 표면관찰 및 효율저하를 분석하였다. 고온고습 시험조건은 KS C IEC-61215에서 제시한 PV 모듈하의 조건을 이용하여 온도 $85^{\circ}C$, 습도 85%, 1000hr 동안 수행하였다. EL(Electroluminescence)촬영을 통하여 Cell 표면의 이상 유 무를 분석한 결과, 시간이 경과함에 따라, 부분적으로 표면이 손상되어 변색되는 것을 확인하였다. 고온고습 시험 전 단결정 Cell 및 다결정 Cell의 효율은 각각 17.7%, 15.5%였으며, 1000hr 수행 후 15.6%, 14.0%로 각각 11.9%와 9.3%의 감소율을 보였다. 또한, 경년 시 나타나는 전기적 특성을 분석하기 위하여 FF(Fill Factor)값을 분석한 결과, 고온고습 시험 후 단결정 Cell은 78.7%에서 75.0%로 4.7%, 다결정 Cell은 78.1%에서 76.7%로 1.8%의 감소율을 보였다. 태양전지 실리콘의 원자배열 및 순도에 따라 효율 변화에 영향을 받아 단결정 Cell이 다결정 Cell보다 효율저하가 크게 나타났다고 판단된다. 또한, FF감소율보다 효율 감소율이 크게 저하된 것을 확인할 수 있었으며, 이는 Cell의 외부환경적 요인에 의한 표면 손상이 p-n접합층 접촉저항과 경년 시 나타나는 FF 감소율보다 크게 영향을 준 것으로 판단된다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 추계 학술논문 발표대회
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• pp.94-95
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• 2018

Prediction of compressive strength of concrete by Maturity Method is applied in construction site. However, due to the use of wired type high-priced equipment, economic efficiency and workability are falling. In this study, a newly developed concrete embedded wireless sensor is used to perform a mock-up test. Next, the concrete compressive strength of the Maturity Method is predicted using Saul and Plowman's function as measured temperature data. The predicted concrete strength at the beginning of the age was the actual strength and stiffness, but the error rate was less than 1% at 28th day.

• 한국정밀공학회지
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• 제31권9호
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• pp.831-838
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• 2014

Chip on glass (COG) bonding using anisotropic conductive film (ACF) is a key technology to assemble a driver IC onto a LCD glass panel. In this paper, an experimental investigation was conducted to investigate the correlation between contact resistance and characteristics of image taken by machine vision based inspection system. The results show that the contact resistance was strongly influenced by the contrast ratio of conductive particle rather than the number of conductive particles. Also, number of conductive particles whose contrast ratio is below 0.75 is crucial for determining the quality of the assembled samples. On the other hand, in the result of high temperature high humidity storage test, the contrast ratio of samples was increased. However, in the case of open-circuit samples after temperature humidity storage test, the number of conductive particles whose contrast ratio is above 0.75 was more than that of the closed-circuit samples.

• 한국육종학회지
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• 제41권4호
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• pp.496-501
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• 2009

저장조건을 달리한 딸기 화분을 FCR Test와 결실률을 바탕으로 하여 화분 활력을 조사하고 암술 주두 활력을 인공수분을 통하여 구명함으로서 딸기 교배 육종시 효율성을 높이고자 하였다. '설향'을 대상으로 화분 활력을 조사하였으며 암술 주두의 수정 능력은 '매향' 등 4품종을 공시하고 화분친은 '설향'을 사용하였다. 딸기 화분은 상대습도 33%이하의 건조한 조건에서는 처리 온도($18^{\circ}C$ 및 $22^{\circ}C$)와 관계없이 수일 동안 높은 활력을 유지하였다. 반면 상대습도가 높을수록 화분 활력의 감소가 컸으며 저장한지 7일차에 대부분의 화분이 활력을 상실하여 결실률이 급격히 감소하였고 이러한 경향은 $18^{\circ}C$보다 $22^{\circ}C$저장 조건에서 결실률이 더욱 불량하였다. 즉, 상대습도가 낮은 경우 화분 활력은 크게 감소하지 않았으며, 온도보다는 습도가 화분 활력을 결정하는 중요한 요인으로 작용하는 것으로 판단된다. 암술의 수정 능력은 품종간의 차이가 있었으나 시설 내부 일평균온도가 $15^{\circ}C$내외일때, 제웅 후 2일차부터 8일차까지 평균 77.2%이상으로 높게 유지되었다. 그러나 결실률은 제웅 후 10일차부터 점차 감소하기 시작하여 12일차 이후에는 일부 품종을 제외하고 급격히 감소하였다. 적산온도를 기준으로 하였을 때, 제웅 후 $45{\sim}140^{\circ}C$내외 범위에서 인공수분을 하는 것이 딸기 결실률을 향상 시킬 수 있을 것으로 판단된다.

• 생물환경조절학회지
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• 제29권3호
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• pp.259-264
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• 2020

본 연구에서는 겨울철 보온으로 인해 야간 및 새벽에 상대습도가 높아지는 온실에 대향류형 환기장치를 설치하고 그 효과를 분석하였다. 대향류형 환기장치는 크기 0.96×0.65×0.82(W×D×H, m)의 케이스에 크기 0.54×0.40×0.75(W×D×H, m)의 PE소재의 열교환 소자와 급기와 배기를 위한 송풍팬(풍량 6,800㎥/h, 소비전력1.7kW) 2대가 내부에 있다. 환기장치는 총 2대를 이용하였으며 토마토의 적정 생육 환경을 고려하여 설정 습도를 80%하고 18시부터 익일 8시까지 온실 내 온도 및 습도를 측정하고 분석하였다. 관행 온실에서 야간 평균 온도 및 습도는 14.9℃, 82.8%, 시험구 온실에서 야간 평균 온습도는 15.1℃, 79.9%로 측정되어 온도는 0.1℃, 습도는 약 3% 차이가 났다. 온실 평균 온도 및 습도를 월별로 비교하고 독립표본 t검정을 통해 분석해 본 결과, 유의수준 1%에서 각 월의 온도는 차이가 없는 것으로 나타났으며 습도는 차이가 있다고 판단된다. 따라서 대향류형 환기장치의 사용이 온실의 습도를 관리하고 작물 생육에 적합환 환경을 조성하여 작물 생산성 향상에 도움을 줄 수 있다고 판단된다. 이 외에도 환기장치 사용에 따른 난방비 증가와 같은 손실적 요소와 이익적 요소를 복합적으로 고려한 추가적인 연구도 필요할 것으로 사료된다.