• Korean Journal of Remote Sensing
• /
• v.39 no.6_1
• /
• pp.1211-1224
• /
• 2023

Clouds cause many difficult problems in observing land surface phenomena using optical satellites, such as national land observation, disaster response, and change detection. In addition, the presence of clouds affects not only the image processing stage but also the final data quality, so it is necessary to identify and remove them. Therefore, in this study, we developed a new cloud detection technique that automatically performs a series of processes to search and extract the pixels closest to the spectral pattern of clouds in satellite images, select the optimal threshold, and produce a cloud mask based on the threshold. The cloud detection technique largely consists of three steps. In the first step, the process of converting the Digital Number (DN) unit image into top-of-atmosphere reflectance units was performed. In the second step, preprocessing such as Hue-Value-Saturation (HSV) transformation, triangle thresholding, and maximum likelihood classification was applied using the top of the atmosphere reflectance image, and the threshold for generating the initial cloud mask was determined for each image. In the third post-processing step, the noise included in the initial cloud mask created was removed and the cloud boundaries and interior were improved. As experimental data for cloud detection, CAS500-1 L2G images acquired in the Korean Peninsula from April to November, which show the diversity of spatial and seasonal distribution of clouds, were used. To verify the performance of the proposed method, the results generated by a simple thresholding method were compared. As a result of the experiment, compared to the existing method, the proposed method was able to detect clouds more accurately by considering the radiometric characteristics of each image through the preprocessing process. In addition, the results showed that the influence of bright objects (panel roofs, concrete roads, sand, etc.) other than cloud objects was minimized. The proposed method showed more than 30% improved results(F1-score) compared to the existing method but showed limitations in certain images containing snow.

• Korean Journal of Remote Sensing
• /
• v.39 no.5_4
• /
• pp.1173-1183
• /
• 2023

Over the past 20 years, Korea's overall import and export cargo volume has increased at an average annual rate of approximately 5.3%. About 99% of the cargo is still being transported by sea. Due to recent increases in maritime cargo volume, congestion in maritime logistics has become challenging due to factors such as the COVID-19 pandemic and conflicts. Continuous monitoring of ports has become crucial. Various ground observation systems and Automatic Identification System (AIS) data have been utilized for monitoring ports and conducting numerous preliminary studies for the efficient operation of container terminals and cargo volume prediction. However, small and developing countries' ports face difficulties in monitoring due to environmental issues and aging infrastructure compared to large ports. Recently, with the increasing utility of artificial satellites, preliminary studies have been conducted using satellite imagery for continuous maritime cargo data collection and establishing ocean monitoring systems in vast and hard-to-reach areas. This study aims to visually detect ships docked at berths in the Busan New Port using high-resolution satellite imagery and quantitatively evaluate berth utilization rates. By utilizing high-resolution satellite imagery from Compact Advanced Satellite 500-1 (CAS500-1), Korea Multi-Purpose satellite-3 (KOMPSAT-3), PlanetScope, and Sentinel-2A, ships docked within the port berths were visually detected. The berth utilization rate was calculated using the total number of ships that could be docked at the berths. The results showed variations in berth utilization rates on June 2, 2022, with values of 0.67, 0.7, and 0.59, indicating fluctuations based on the time of satellite image capture. On June 3, 2022, the value remained at 0.7, signifying a consistent berth utilization rate despite changes in ship types. A higher berth utilization rate indicates active operations at the berth. This information can assist in basic planning for new ship operation schedules, as congested berths can lead to longer waiting times for ships in anchorages, potentially resulting in increased freight rates. The duration of operations at berths can vary from several hours to several days. The results of calculating changes in ships at berths based on differences in satellite image capture times, even with a time difference of 4 minutes and 49 seconds, demonstrated variations in ship presence. With short observation intervals and the utilization of high-resolution satellite imagery, continuous monitoring within ports can be achieved. Additionally, utilizing satellite imagery to monitor changes in ships at berths in minute increments could prove useful for small and developing country ports where harbor management is not well-established, offering valuable insights and solutions.

• The Journal of Korean Society for School & Community Health Education
• /
• v.12 no.3
• /
• pp.29-41
• /
• 2011

배경 및 목적 : 미국과한국양국의대학생의음주문제는심각한사회문제이며, 대학생의음주문제를예방하기 위한 다양한 노력들이 시도되고 있다. 본 연구는 미국과 한국대학생들의 음주와 폭음에 대한 인식 및 태도에 차이가 있는지를 비교 분석하기 위해 설계되었다. 방법 : 데이터는 2001년 미국의 하버드 보건대학원의 College Alcohol Study (CAS) 팀에서 미국의 120개 4년제 대학에서 10,904명에게서 조사한 원자료와 한국에서는2003년 삼육대학교 보건복지대학원의 Korean College Alcohol Study (KCAS) 팀에서 전국의 60개 4년제 대학의 2,385명의 원자료를 함께 통합하여 사용하였다. 이 자료의 특징은CAS에서 개발한설문지를 한국과 미 국양측에서 공동으로 사용하여 양 국가를 대표한 4년제 대학생의 표본을 대상으로 음주와 관련된 조사를 수행한 점이다. 결과 : 한국남학생들이 폭음할 기회가7.74배더많고 여학생의 경우는3.36배 더많다. 지난 한달동안 3회 이상 술 취한 경험율에서 한국 남학생들의 경험율이 34.3%로 미국의 20.4%보다 많고, 여학생의 경우도 24.6%로 미국 여학생의 11.1%보다 현저히 더 많다. 한국 대학생들의 폭음자 비율이 미국 대학생들의 폭음자 비율보다 많은 것과같이, 한국 대학생들이 미국의 대학생들 보다 폭음이 안전한 것으로 인식하고 있으며, 음주에있어서도더욱허용적인태도를가지고있다. 한국남학생의78.4%와 여학생의67.3%가 폭음 이상의 량을 안전하다고 인식하고 있다(미국은 남학생은 50.3%, 여학생은 34.1%). 폭음에 해당하는 음주량(남자는5잔 이상, 여자는4잔 이상)을안전하다고인식하는정도에서한국의대학생들이미국의대학생들에 비해서 남학생은 4.06배, 여학생이 3,96배 더 높다. 결론 : 한국 학생들 중에서도 음주의 량이 더 많은 학생들이 다른 학생들보다 음주와 술 취함과 폭음에 관하여 더욱 허용적이고, 안전한 음주에 대해 더욱 둔감한 태도와 신념을 보이고 있다.

• Journal of the Korean Wood Science and Technology
• /
• v.26 no.1
• /
• pp.7-13
• /
• 1998

In order to reconstruct the traditional technology of Korean golden varnish(Hwangchil) made from the exudates of D. morbifera, this study in the second step was carried out to analyze the chemical composition and oil properties of the exudates for coatings and bark extractives made from the trees of D. morbifera more than 20 years old grown in Wando and Jejudo islands in the southwestern part of Korean peninsula according to the physiological seasons. The results obtained are as follows: 1. The exudates appeared to be a phytoalexin because it exudated after several days in tapping only in summer season. 2. Both the exudates and bark-extracts with acetone contained 50~60% unsaponifiables and 30~50% saponifiables 3. A major component of essential oil in bark-extractives was ${\beta}$-cubebene and reached to 60~80%, while that of exudates included only 34% ${\beta}$-cubebene and some other compounds such as ${\beta}$-cadinene of 12%, aromadendrene of 9%, ${\beta}$-selinene of 9%, CAS030021-74-0 of 10%, etc. in GC-MS spectrometer. 4. A mjor component of fatty oil fraction in bark-extractives was linoleic acid and reached to more than 60%, while the exudates had mostly other components such as terpenes and phenolics instead of fatty acids accordint to GC-MS spectrometer. 5. Iodine value of samples after oil refining had 214mg/g in the exudates and more than than 150mg/g in bark-extractives, so the latter belonged to a drying oil.. 6. Therefore, the exudates from D. morbifera for traditional Korean golden varnish seems to have beeen used to a good varnish because it has some specific compounds different from its bark-extractives or general varnishes.

• Child Health Nursing Research
• /
• v.5 no.3
• /
• pp.250-261
• /
• 1999

This study has been conducted on the nonequivalent control group Pretest-posttest design in quasi experimental basis and newly born premature infants from intensive care unit of G Medical University Hospital in Inchon Metropolitan were selected in two groups of 21 infants each. The first group for experimental and the other for control. Data has been collected form October 30, 1997 to August 29, 1998. For the experimental group tactile and kinesthetic stimulation was applied 2 times a day for 10 days(10:00～ll:00 hours in the morning and 17:00～18:00 in the afternoon). As, a weight weighing instrument, electronic indicator scale(Cas Co. korea) was used. Collected data were analyzed with the SAS program using x²-test, student t-test, repeated measures ANOVA, Pearson correlated coefficient and Stepwise multiple regression. The result were as follow. 1. As for the daily weight gain, the experimental group showed first change in weight and this group also showed higher weight in the average weight than the control group. Statistically, however. there was no significant factor between the two groups. 2. In the correlation between general characteristics and weight gain, gestation Period. apgar score, admission Period before study, N.P.O. period after birth, recovery Period to birth weight showed statistical significance negative correlation with weight gam in the experimental group than control group. 3. In the factor with affected the weight gain by general characteristics showed recovery period to birth weight and head circumference in the experimental group, control group showed recovery period to birth weight, N. P. O. period after birth. admission period before study, feeding amount, weight of study. In conclusion. the sensory stimulation in this study showed a Positive aspect through there was no statistical significance in the weight gam. Tn the correlation of general characteristics and weight gam showed statistical significance negative correlation The main factor which affected the weight gain by general characteristics showed recover period to birth weight.

• Fisheries and Aquatic Sciences
• /
• v.1 no.2
• /
• pp.269-275
• /
• 1998

Spider crabs, Libinia emarginata, were eyestalk-ablated unilaterally and bilaterally to manipulate endogenous methyl farnesoate (MF) to increase during the embryogenesis. Endogenous MF were measured weekly over the embryogenesis of the crab, using HPLC with the aids of GC/MS and MS database (CAS 010485-70-8) for the identification of the hormone. Initial MF titers both in the hemolymph and embryos of intact control were at bottom levels and the hormone concentrations kept unchanged (p<0.05), reflecting physiological unnecessaries of the hormone in the embryogenesis. Eyestalk ablation significantly stimulated the crabs to increase endogenous MF in both tissues (p<0.0l). In the response of the embryos to the increased MF, no growth stimulations were observed, at least, in the first part of embryogenesis. The increased mortalities and immature sheddings of embryos resulted from the crabs under the influence of elevated MF in both tissues, instead, suggesting that the elevated MF against the crab's requirement blocked the normal developmental process of the crab embryos. These data can give crustacean endocrinologists some insights to understand the effects of the hormone on the crustacean reproduction studied previously in which JH analogs ambiguously affected the crustacean reproduction depending on the reproductive stages. The data also can give shrimp aquaculturists some implication of a possible generation of unfavorable shrimp seeds attributed to elevated egg MF originated from their eyestalk-ablated mother shrimp.

• Proceedings of the CALSEC Conference
• /
• 1999.07a
• /
• pp.277-299
• /
• 1999

Since Chrysler Motor Co. had experienced the digital development system in the beginning of 1990's, most of leading automobile companies are trying to apply a digital information system for their own business process reengineering based upon concurrent engineering system from product planning phase. This is called as virtual DMU(Digital Mock-Up) system instead of the traditional PMU(Physical Mock-Up) system. By using the virtual prototype, all of the design requirements and system specifications can be checked, changed and optimized more quickly and more efficiently. This paper consists of five chapters for the DMU information system. In the 1$^{st}$ chapter, the principle of digital design system is suggested by using four basic modules such as product design module, process design module, manufacturing system design module and central control module. The basic scheme of DMU is introduced with the benefits of application in the chapter 2. In the chapter 3, a digital design process of new car development is explained with the detailed DMU design and design review processes. In the chapter 4, the practical DMU manufacturing techniques and applications are introduced as CAD/CAM analyses, DPA(Digital Pre-Assembly)reviews for development, production, operation and maintenance phases, digital tolerance analyses and digital factory analyses for assembling line simulation, automated robot welding processes, production jig ＆ fixtures and painting process simulation. Finally, the activities of digital design support; CAS-styling, CAE-engineering and CAT-testing are summarized for design optimization in the chapter 5. As today's automobile manufactures and related business organizations are struggling to compete in the global marketplace, they are concentrating on efficient use of DMU information system to reduce the new car development cost, to have shorten the delivery schedule and to improve product design quality. To meet the demand of those automobile industries on digital information systems, the CALS(Computer aided Acquisition and Logistics Support) and EC(Electronic Commerce)initiative has been focused as a dominant philosophy in defense ＆ commercial industries, specially automobile industries.s.

• Journal of Space Technology and Applications
• /
• v.3 no.3
• /
• pp.229-238
• /
• 2023

One of the important ways to improve the performance of magnetometers in satellite exploration is to reduce magnetic noise from satellites. One of the methods to decrease magnetic noise is by extending the satellite boom. However, this approach is often not preferred due to its high cost and operational considerations. Therefore, in many cases, removing interference from the satellite platform in the measured dataset is widely utilized after data acquisition. In this study, we would like to introduce an algorithm for removing magnetic noise observed from magnetometers installed on two solar panels and one main body without a boom.

• The Journal of Korean Academy of Prosthodontics
• /
• v.39 no.6
• /
• pp.709-734
• /
• 2001

The aims of this experiment were to investigate the strain and temperature changes simultaneously within autopolymerzing acrylic resin specimens. A computerized data acquisition system with an electrical resistance strain gauge and a thermocouple was used over time periods up to 180 minutes. The overall strain kinetics, the effects of stress relaxation and additional heat supply during the polymerization were evaluated. Stone mold replicas with an inner butt-joint rectangular cavity ($40.0{\times}25.0mm$, 5.0mm in depth) were duplicated from a brass master mold. A strain gauge (AE-11-S50N-120-EC, CAS Inc., Korea) and a thermocouple were installed within the cavity, which had been connected to a personal computer and a precision signal conditioning amplifier (DA1600 Dynamic Strain Amplifier, CAS Inc., Korea) so that real-time recordings of both polymerization-induced strain and temperature changes were performed. After each of fresh resin mixture was poured into the mold replica, data recording was done up to 180 minutes with three-second interval. Each of two poly(methyl methacrylate) products (Duralay, Vertex) and a vinyl ethyl methacrylate product (Snap) was examined repeatedly ten times. Additionally, removal procedures were done after 15, 30 and 60 minutes from the start of mixing to evaluate the effect of stress relaxation after deflasking. Six specimens for each of nine conditions were examined. After removal from the mold, the specimen continued bench-curing up to 180 minutes. Using a waterbath (Hanau Junior Curing Unit, Model No.76-0, Teledyne Hanau, New York, U.S.A.) with its temperature control maintained at $50^{\circ}C$, heat-soaking procedures with two different durations (15 and 45 minutes) were done to evaluate the effect of additional heat supply on the strain and temperature changes within the specimen during the polymerization. Five specimens for each of six conditions were examined. Within the parameters of this study the following results were drawn: 1. The mean shrinkage strains reached $-3095{\mu}{\epsilon},\;-1796{\mu}{\epsilon}$ and $-2959{\mu}{\epsilon}$ for Duralay, Snap and Vertex, respectively. The mean maximum temperature rise reached $56.7^{\circ}C,\;41.3^{\circ}C$ and $56.1^{\circ}C$ for Duralay, Snap, and Vertex, respectively. A vinyl ethyl methacrylate product (Snap) showed significantly less polymerization shrinkage strain (p<0.01) and significantly lower maximum temperature rise (p<0.01) than the other two poly(methyl methacrylate) products (Duralay, Vertex). 2. Mean maximum shrinkage rate for each resin was calculated to $-31.8{\mu}{\epsilon}/sec,\;-15.9{\mu}{\epsilon}/sec$ and $-31.8{\mu}{\epsilon}/sec$ for Duralay, Snap and Vertex, respectively. Snap showed significantly lower maximum shrinkage rate than Duralay and Vertex (p<0.01). 3. From the second experiment, some expansion was observed immediately after removal of specimen from the mold, and the amount of expansion increased as the removal time was delayed. For each removal time, Snap showed significantly less strain changes than the other two poly(methyl methacrylate) products (p<0.05). 4. During the external heat supply for the resins, higher maximum temperature rises were found. Meanwhile, the maximum shrinkage rates were not different from those of room temperature polymerizations. 5. From the third experiment, the external heat supply for the resins during polymerization could temporarily decrease or even reverse shrinkage strains of each material. But, shrinkage re-occurred in the linear nature after completion of heat supply. 6. Linear thermal expansion coefficients obtained from the end of heat supply continuing for an additional 5 minutes, showed that Snap exhibited significantly lower values than the other two poly(methyl methacrylate) products (p<0.01). Moreover, little difference was found between the mean linear thermal expansion coefficients obtained from two different heating durations (p>0.05).

• Journal of Plant Biotechnology
• /
• v.46 no.3
• /
• pp.137-142
• /
• 2019

Gene edited crops can be classified as SDN-1, SDN-2 and SDN-3 group depending on their mutation's range and the usage of donor DNA. The SDN-1 and SDN-2 crops, in particular, could be developed as 100% transgene-free, which do not contain any DNA fragment of the vector or guide RNA used for gene editing such as CRISPR Cas9 system. Therefore, there are no scientific methods available for the detection of these crops and differentiation with the one produced by conventional cross breeding techniques. Additionally, it would be impossible to properly implement the existing GMO regulation law, in particular, the national legislation for "GMO labelling". In this regard, Australia has announced that SDN-1 crops will not be subjected to the existing GMO regulation. Furthermore, Argentina and Brazil have established a new policy that GE crops with no transgene (100% transgene-free crops) should be exempted from the scope of the GMO. In addition, Japan has also announced that "an organism that has no remnants of inserted nucleic acid processed extracellularly is not subjected to the Cartagena Act". It means that SDN-2 crops can also be exempted from the scope of GMO. In this trend, in South Korea, I suggested that gene edited crops with no remnants of inserted foreign DNA fragments should be excluded from the existing GMO regulation. Thus, I expect that diverse elite crop lines should be developed by using advanced gene editing technologies