• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.37 no.6
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• pp.465-472
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• 2019

The SPR (Single Photo Resection) is widely used as a method of estimating the EOPs (Exterior Orientation parameters) at the time of taking a photograph, but it requires an initial value and has a disadvantage of being sensitive to the initial value. In this study, we introduce quaternion-based single photo resection and PnP (Perspective-n-Point) algorithm that do not require initial values and compare the results. Photos were taken using a general smartphone, and the ground control point acquisition was based on the hybrid MMS (Mobile Mapping System) point cloud data possessed by the researchers. As a result, when the collinear condition based SPR is true value, quaternion-based SPR has higher attitude angle estimation accuracy than PnP algorithm. In case of camera position estimation, both algorithms showed accuracy within 0.8m when compared with ground control points.

• Journal of Bio-Environment Control
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• v.17 no.1
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• pp.51-59
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• 2008

Lettuce, a typical light-induced seed germination type, exhibits different germination responses according to cultivars, light quality, and plant growth regulator (PGR) treatments. Germination rates in most tested cultivars were over 85% under both white and red light, and were slightly decreased by blue light. Although photo-inhibition in germination was observed from most cultivars by far-red light, 'Cheongguangcheongchima', 'Okdol', and 'Manchudaecheongchima' could be classified as photo-insensitive lettuce cultivars by exhibiting the germination rates as 78,63, and 48% under for-red light, respectively. 6-Benzylamino purine (BAP) and kinetin promoted seed germination and normal seedling production under far-red light, but ethephon did not show any positive effects. Cytokinins such as BAP, kinetin, thidiazuron (TDZ), and zeatin overcame photo-inhibition of seed germination even the concentration of below $50\;mg{\cdot}L^{-1}$. However, auxins such as IBA, 2,4-D, and NAA failed to overcome the far-red light-induced photo-inhibition.

• Korean Journal of Environmental Biology
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• v.24 no.2 s.62
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• pp.126-137
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• 2006

Effect of night-lights on zooplankton attraction has been studied in Tongyeong marine ranch area during the period from 12 July to 30 August, 2004. Each sampling has been carried out to collect zooplankton from both control area in natural waters experiment area of night-lights waters at night. A total of 43 taxa of zooplankton occurred during the study. Copepods showed the prosperity in species number with 15 species. Acartia erythraed and Copepodite occurred abundantly in night-lights waters. Zooplankton abundance appeared to increase in night-lights mainly due to the gathering of copepods and larvae through the study period. Average $3\sim166$ times of zooplankton abundance was recorded in night-lights when compared with that in control area of natural waters due to the gathering of copepods and larvae. Cluster analysis, based on monthly abundance data of the 13 most frequent species, showed that the species were seperated into two different groups: the photo-positive group and the photo-negative group.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.6
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• pp.687-695
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• 2011

Many internet portals provide maps with spatial information services. Recently, various images including aerial, satellite, street view, and photo-realistic 3D city models are provided as well as maps. This study suggested a method for geometric correction of the panoramic aerial images in the internet portal and 3D building modeling using information which is available in the internet. The key of this study is to obtain all necessary data easily from internet without restrictions. Practically, the ground control coordinates could be available from geo-referenced internet maps, and stereo pairs of the aerial images and close-range photographs for photo-realistic object modeling are provided by the internet service. However, the ground control points are not suitable for accurate mapping. RMSE of the plotting was about 9 meters and reduced upto 4 meters after coordinate transformation. The proposed methods would be applicable to various applications of photo-realistic object modeling which do not require high accuracy.

• Journal of Korean Society of Forest Science
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• v.89 no.2
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• pp.161-166
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• 2000

Classified handmade Korean paper which has been commonly used as the material for the paper cultural assets divide into four classes. We irradiated xenon arc lamp, which has almost the same spectrum distribution as natural sunlight, to test photo-induced of discoloration according to PEG molecular weight and concentration. So, we reach the followings. 1) Unbleached handmade Korean paper with PEG showed rapid decrease of brightness for 10 hours after photo-irradiation, regardless of molecular weight of PEG, but, after 10 hours, it showed gradual increase of brightness. From this, it proved that there was an effect of preventing discoloration of photo-irradiation. 2) Chemical bleached handmade Korean paper showed increase of brightness after 20 hours. Though time was delayed in increase of brightness, there was also an effect of preventing discoloration of photo-irradiation in chemical bleached paper. 3) Handmade Korean paper made with abet-mosk showed the lowest of brightness when it was tested on 400-20% PEG. Before photo-irradiation, the brightness of paper, applied it, was the lowest, but it showed the least difference of brightness after photo-irradiation. From this, it proved that there was the greatest effect of preventing discoloration in this paper. 4) Preventing yellowish, the first phenomena by photo-irradiation ageing with applying PEG was proved that there was the decrease of value of $b^*$ +, and increase value of $L^*$, which could fairly prevent decrease of brightness.

• Proceedings of the KIPE Conference
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• 2004.07a
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• pp.219-223
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• 2004

Since rotor position information is necessary to drive the SRM, absolute-encoder, resolver and incremental encoder is used to detect a rotor position. But, it is not desirable to use a high price encoder and microprocessor under the condition of the simple driving system when precision control is not demanded. In this paper, only using the reflective type two photo-sensors replaces the conventional opto-interrupter and slotted-disk, which not only remove a slotted-disk section but drive three-phase 6/4 pole SRM bidirectionally, Therefore, control circuit can compose common analog device with low price.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1745-1748
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• 2007

First, thin-film photodevices are evaluated, and a p/i/n thin-film phototransistor (TFPT) is recommended because the photo-induced current is relatively high and independent of the applied voltage. Next, an artificial retina is developed using the p/i/n TFPTs, and it is found that it can detect photo illuminance profile with sensitivity control.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.89-92
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• 2000

Laser claddmg 1s thc deposition of material on the surface of a part or workpiece. Cladding of metals produces a 100% dense metallurgically-bonded coating with minimal dilution for enhanced corrosion, abrasion and wear resistance. Despite of minimal heat Input and reduced processing time, cladding quality 1s affected by various process condition such as laser power and feed rate. Therefore, it is necessary to develop the momtoring and control methods of laser cladding process for the best cladding quality. In this paper, laser cladding monitoring system using CCD camera for measuring cladding pool shape, and photo-diode sensor for detecting optical signal emitted from the cladding front is introduced The variables extracted using this system can be apphed to control the laser cladding system to achieve the best claddmg results..

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.2
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• pp.105-111
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• 2004

In this paper, a new self-oscillated type high voltage power supply for the OPC(Organic Photo Conductor) charge is proposed, which has variable constant current source characteristics to improve the charge characteristic of the OPC roller. The proposed control method enables high quality printing characteristics regardless of the circumstance change such as ambient temperature or humidity by changing the current reference signal. To verify the proposed control method various experiments are performed.

• Journal of Bio-Environment Control
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• v.15 no.2
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• pp.173-176
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• 2006

The relationship between source leaf position and photo-assimilate translocation and distribution was characterized for tomato (Lycopersicon esculentum Mill) grown in the greenhouse. Three different positions of source leaf on the stem (first node above or below the first fruit cluster and $5^{th}$ node above the first fruit cluster) were tested for their influence on $^{14}CO_2$ assimilation and transfer to different parts of the plant. The leaves at the $5^{th}$ node above the first fruit cluster transferred the highest (57%) proportion of $C^{14}$ to other plant parts, followed by leaves home on the first node below the first fruit cluster (50%), and the first node above the first fruit cluster (39%). In all treatments, fruits served as the strongest sink for $C^{14}$, followed by stem, leaf, and root tissues. The leaf home on the $5^{th}$ node above the first fruit cluster transferred the largest amount of $C^{14}$ to the second fruit cluster.