• Applied Chemistry for Engineering
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• v.10 no.7
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• pp.1073-1078
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• 1999

The objectives of this study are to examine the applicability of waste slurry from soda ash manufacturing industries as a coagulant for the treatment of wastewater containing fine silica particles, and to reduce the cost of wastewater treatment containing silica. Acceptable water quality can be obtained with a little dosing of waste slurry by gelation before the coagulation process so it could be concluded that the waste slurry from soda ash can be used as a coagulant. Based on the results of experiments, the optimum pH of gelation for silica in wastewater was around five and the treatment process with the gelation of silica could reduce the chemical dosage and waste sludge after coagulation. Dewatering and settling characteristics of the floc after coagulation with the waste slurry are better than those of the floc after coagulation with the lime milk only.

• Korean Journal of Heritage: History & Science
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• v.50 no.3
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• pp.64-87
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• 2017

Dahoe is a traditional braid in Joseon Dynasty. There are many Dahoe artifacts, which can give us a glimpse of the costume, culture, and life of that era. The study of Dahoe is necessary in various fields, but it is difficult because this manufacturing technique has been passed down from hand to hand. Few studies have been done so far. This research examines the manufacturing technique of KwangDahoe which is passed down by Maedeupjang (Decorative Knotting) and is generally used for knotting and/or tying objects. The main characteristic of TieKwangDahoe, made through the same method as WonDahoe, is the square hole in the middle. It was impossibile to remake the original braid because there is no confirmed number of the strand. Especially it is very difficult to do conservation and restoration on serious degradation state of the fiber. Therefore, it is necessary to analyze the non-destructive manufacturing techniques method for Dahoe and assess their applicability. First, we analyzed the artifacts' manufacturing technique based on the database of the Dahoe's manufacturing technique. In order to do that, we undertook schematization, restoration, morphological analyzation of the Dahoe. And then, X-ray CT scans were performed to improve the reliability of the DB. These results of scanning were interpreted based on the manufacturing technique. The selected Tie-KwangDahoe on the sword for the study are artifacts including artistic value and symbolism in Joseon Dynasty. Based on the analysis of the manufacturing technique, we found that both artifacts were made of 20-strand braid of single cross according to the length-scale measure. It was manufactured using 8-strand on left-right side, 12-strand on front-back side by the braiding manufacturing technique method Finally, this research suggests non-destructive analysis method of Dahoe's manufacturing technique is based on the database and the analysis results. I hope this research can be useful in various professional fields of Dahoe in the future. Moreover, I hope this can be of any help in preserving Korean cultural heritage.

• Journal of the Korea Society of Computer and Information
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• v.18 no.10
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• pp.81-88
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• 2013

Since nowadays mobile phone messages are flourishing, the application of electronic coupon (e-coupon) will become a trend for mobile users. E-coupon for mobile commerce can provide mobility for users and distribution flexibility for issuers. In this paper, we propose a mobile e-coupon system that just applies some simple cryptographic techniques, such as one-way hash function and XOR operation. In our system, the customer can control the number of issued e-coupons and the issuer can prevent them from double-redeeming. The customer does not need to perform any exponential computation in redeeming and transferring the coupons. Our scheme uses one-way hash chains for preventing from double-spending.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.10
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• pp.366-373
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• 2019

Combat uniforms require higher tensile and tear strength than civilian products, and applied infrared reflectance from the recently developed nighttime fluoroscopy equipment to ensure combatant survival at night. Unlike other uniforms for civilian use, combat uniforms require durability against laundering because they may not be supplied again, once originally provided. Therefore, this study examined the changes in strength and changes in infrared reflectance after multiple washing of combat uniforms. The experiment confirmed that the strength change after the washing of combat uniforms 15 times was maintained in the same manner as the result after washing five times. In the case of infrared reflectance, the difference in reflectance after multiple washing treatments was greater than that in the case where washing was not performed. Therefore, although the durability in the case of combat uniforms is strong, it is necessary to maintain a reflectance higher than a certain level through the development of materials and the development of dyes.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.05a
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• pp.625-627
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• 2013

모바일 기기의 성능 향상과 모바일 인터넷 서비스의 활성화, 스마트폰 시장의 급속한 성장으로 모바일 쿠폰 시장 빠르게 활성화 되고 있으나 이로 인한 다양한 문제점이 발생되고 있다. 본 논문에서는 이러한 문제점들을 방지하고 일회성의 쿠폰 이외에 다회 이용 가능한 모바일 전자상품권 프로토콜을 제안한다. 동형암호를 적용하여 모바일 기기에서 암호화와 복호화 연산을 최소화하도록 설계하였으며, 쿠폰의 정보는 암호화되고 사용시마다 새로 생성되도록 하여 이중사용과 복제가 불가능 하도록 설계하였다.

• 대한생식의학회:학술대회논문집
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• 2003.12a
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• pp.90-90
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• 2003

• Journal of the Korean Society of Costume
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• v.66 no.5
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• pp.133-148
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• 2016

This study examined dahoe(多繪-braided cord) and mangsu(網綬-ornament of husu for ceremonial dress) used in myeon gwan(冕冠), daedae(大帶), and husu(後綬) among royal formal dresses in the Joseon Dynasty(1392-1910) based on historical materials including literature, relics, and paintings. The results of this study are as follows. In myeon-gwan, dahoe was used for cap strings, goeing(紘) and yeong(纓). Cap strings were applied to the king, the Crown Prince, and the eldest son of the Crown Prince regardless of their status, and they showed differences among the periods. Both goeing and yeong were used during the early period of Joseon, and then only yeong was used in the late period. As goeing was removed and only yeong was used in the late period, patterns combining goeing and yeong, in color and wearing method, appeared. Dahoe used in cap strings is dongdahoe(童多繪-a kind of braided cord). In daedae, 'nyuyak(紐約)' was tied up to its fastening part. The material of nyuyak was changed from dongdahoe in the early Joseon Dynasty to guangdahoe(廣多繪-a kind of braided cord) in the late period, and the method of using it was also changed. Husu was imported from Beijing in China during the early period of the Joseon Dynasty, but in 1747, it was regulated to be woven in Joseon, and at that time, King Yeongjo attempted to restore the institution of weaving husu with "320 su(首)," namely, 6,400 strands as specified for the status of a prince of the Ming Dynasty.

• Clinical and Experimental Reproductive Medicine
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• v.37 no.2
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• pp.135-142
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• 2010

Objective: To evaluate the effectiveness of soft stimulation protocol using GnRH antagonist/clomiphene citrate (CC)/recombinant FSH (rFSH) in patients undergoing controlled ovarian stimulation (COS) with intrauterine insemination (IUI), compared with GnRH antagonist multiple dose protocol (MDP) using GnRH antagonist/rFSH. Methods: Eighty infertile women were randomized to soft stimulation protocol group (n=40) or GnRH antagonist MDP group (n=40). In both groups, IUI was performed 36~40 hours after hCG injection. Statistical analysis was performed using Student's t-test, $\chi^2$ test or Fisher's exact test as appropriate. Results: Total dose and days of rFSH required for COS were significantly fewer in soft stimulation protocol group (p<0.001, p<0.001). A premature LH surge did not occur in any patients of both groups. Clinical pregnancy rate per cycle was similar between the two groups. Conclusion: Soft stimulation protocol provides comparable pregnancy rates to GnRH antagonist MDP despite fewer total dose and days of rFSH, and so can become one of the patient-friendly, cost-effective alternatives for infertile patients undergoing COS with IUI.

• Journal of Embryo Transfer
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• v.13 no.3
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• pp.207-212
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• 1998

This study was conducted to determined if single subcutaneous (s.c.) injection of Folltropin-V dissolved in polyethyleneglycol (PEG) can replace as the standard multiple intramuscular (i.m.) injection. The results suggest that the s.c. treatment produced more corpora lutea, embryos recovered and transferable embryos as compared to the i.m. treatment (p<0.05). This study indicates that a single s.c. injection of Folltropin-V dissolved in PEG was effective for superovulatory response and embryo yield in Korean cattle.

• Journal of Korean Society of Transportation
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• v.22 no.5
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• pp.89-97
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• 2004

The Korea Air Force(KAF) has operated freight flights based on the prefixed time and route schedule, which is adjusted once in a month. The major purpose of the operation of freight flights in the KAF is to distribute necessary supplies from the home air base to other air bases. The secondary purpose is to train the young pilots to get more experiences in navigation. Each freight flight starts from and returned to the home air base everyday except holidays, while it visits several other air bases to accomplish its missions. The study aims to forecast freight demand at each base by using time series analysis, and then it tried to optimize the cost of operating flights by solving vehicle routing problem. For more specifically, first, several constraints in operating cargos were defined by reviewing the Korea Air Force manuals and regulation. With such constraints, an integer programming problem was formulated for this specific routing problem allowing several visits in a tour with limitation of maximum number of visits. Then, an algorithm to solve the routing problem was developed. Second, the time series analysis method was applied to find out the freight demand at each air base from the mother air base in the next month. With the forecasted demands and the developed solution algorithm, the oprimum routes are calculated for each flight. Finally, the study compared the solved routing system by the developed algorithm with the existing routing system of the Korea Air Force. Through this comparison, the study proved that the proposed method can provide more (economically) efficient routing system than the existing system in terms of computing and monetary cost. In summary, the study suggested objective criteria for air routing plan in the KAF. It also developed the methods which could forecast properly the freight demands at each bases by using time series analysis and which could find the optimum routing which minimizes number of cargo needed. Finally, the study showed the economical savings with the optimized routing system by using real case example.