수확방법에 따른 단벌기 목재에너지림 목재칩의 생산 및 연료 특성

최윤성,오재헌,조민재,문호성 강원대학교 농업생명과학연구원 2022 농업생명환경연구 Vol.34 No.3

This study was conducted to compare the productivity and cost of harvesting and processing system between manual and mechanized methods in short-rotation coppice (SRC). The wood chips were divided into class based on their characteristics. There was also a consideration whether the fuel conditions of the energy facilities were suitable. The cost of mechanized harvesting system (48,525 won/Gwt) was lower than that of manual harvesting system (107,350 won/Gwt) by approximately 54.8%. The results of the fuel properties analysis for wood chips A (chipping immediately after harvesting) and wood chips B (chipping after drying) showed that wood chips A was not suitable because of the bulk density, and wood chips B was evaluated to be a second class based on the quality standards of wood chips in all conditions. The wood chips B was available at all energy facilities except gasification combined heat and power system (CHP), which required low moisture content (less than 13%). In addition, if the quality of wood chips was improved, (increased storability, uniformity of wood chips size, and reduced fines) by performing drying and screening operation after chipping, it can be used for all energy facilities.

스마트 카드 분실 공격에 안전한 사용자 인증 스킴의 취약점 및 개선방안

최윤성 국제인공지능학회 2016 한국인터넷방송통신학회 논문지 Vol.16 No.6

With the rapid development of Internet and communication network technology, various studies had proceeded to develop the technology of wireless sensor networks. Authentication schemes for user and sensor are critical and important security issue to use wireless sensors legally. First, Das introduce a user authentication scheme using smart card and password for wireless sensor networks, various studies had proceeded. Chem et al. suggested a secure user authentication scheme against smart card loss attack but Chen et al. scheme does not still resolve some security vulnerability such as perfect forward secrecy, session key exposure by gateway node, anonymity, and the password check. To resolve the problems, this paper proposes a security enhanced user authentication using the fuzzy extraction, elliptic curves cryptography and dynamic ID and analyzes the security.

Automatic Tension Control of a Timber Carriage Used for Biomass Collection

최윤성,김대현,오재헌,어승희,최희진 한국농업기계학회 2012 Journal of Biosystems Engineering Vol.37 No.2

Purpose: A lab-scale timber carriage using a servo motor system was built. When two motors move a carriage, wire tension is changed according to the different line speeds caused by a wire drum’s changing diameter, leading to inappropriate traveling characteristics of the carriage. In order to overcome this problem, PID Control was used to control the motor speed. Methods: Ziegler-Nichols method was used to determine PID gains. Results: The initial PID gains were 1.8, 0.025, and 0.006, respectively, and optimal gains of 1.4 and 0.010 for P and I gain were obtained experimentally. Conclusions: The results showed that constant wire tension could be maintained by controlling the speed of the motor using PI control. Overshoot occurred at initial motor operation due to vibration and elasticity of the wire itself.

수종에 따른 스트로크 하베스터의 벌도⋅조재작업 생산성 및 비용

최윤성,조민재,문호성,오재헌 한국산림과학회 2022 한국산림과학회지 Vol.111 No.4

Chainsaw use for motor-manual timber harvesting in South Korea is associated with worker safety issues. However, forestry operations such as timber harvesting have already been mechanized to reduce hazards to workers and increase productivity. This study analyzed the productivities and costs of felling and processing, felling and processing using an excavator-based stroke harvester for Pinus rigida and Quercus mongolica stands. To efficiently operate the stroke harvester, we developed a regression equation to estimate the productivities of felling and processing, felling, and processing operations,and we conducted sensitivity analysis of the operation costs using DBH and machine utilization. The felling and processing productivity was 6.53 and 4.02 m3/SMH for P. rigida and Q. mongolica, respectively, and the cost was 17,983 and 29,210 won/m3, respectively. The felling productivity for P. rigida and Q. mongolica was 40.9 and 23.0 m3/SMH, respectively, and the cost was 2,667 and 4,743 won/m3, respectively. The processing productivity for P. rigida and Q. mongolica was 8.25 and 7.75 m3/SMH, respectively, and the cost was 15,296 and 16,283 won/m3, respectively. In the developed regression equation, the DBH, traveling distance, and number of cuttings were found to be important factors (p<0.05). Therefore, it is necessary to construct a DB considering the various conditions and species associated with harvester operations, and further research is needed to increase the accuracy of predicting operation productivity and costs. 체인톱에 의한 인력위주의 임목수확작업은 안전사고 문제에 직면하고 있으나, 기계화작업을 통해 작업자의 위험성을 줄이고 생산성을 높일 수 있다. 본 연구는 국내 수종에 적합한 굴삭기 기반의 스트로크 하베스터을 이용하여 리기다소나무(Pinus rigida)와 신갈나무(Quercus mongolica)를 대상으로 벌도+조재작업, 벌도작업과 조재작업으로 구분하여 생산성과 비용을 분석하였다. 스트로크 하베스터의 효율적인 운영을 위한 작업생산성 예측모델 개발과 직경 및 기계이용률에 따른 작업비용 변화를 분석하였다. 벌도+조재작업에서 리기다소나무와 신갈나무의 생산성은 각각 6.53 m3/SMH와 4.02 m 3/SMH이고, 비용은 각각 17,983 won/m3과 29,210 won/m3으로 나타났다. 벌도작업에서 리기다소나무와 신갈나무의 생산성은 각각 40.9 m3/SMH와 23.0 m3/SMH이고 비용은 각각 2,667 won/m3와 4,743 won/m3으로 나타났다. 조재작업에서 리기다소나무와 신갈나무의 생산성은 각각 8.25 m3/SMH와 7.75 m3/SMH이고, 비용은 각각 15,296 won/m3와16,283 m3/SMH으로 나타났다. 스트로크 하베스터를 이용한 벌도+조재작업, 벌도작업과 조재작업의 생산성에 대한 중요인자는 흉고직경, 이동거리와 절단횟수가 선정되었으며(p<0.05), 이를 이용하여 작업생산성 예측모델을 개발하였다. 따라서 스트로크 하베스터를 이용한 벌도 및 조재작업에서 다양한 조건과 수종을 고려한 DB 구축으로 생산성과 비용 예측의 정확성을 높이기 위한 연구가 필요할 것으로 판단된다.

MXene-polyurethane Composite Scaffold for Rotator Cuff Tendon Repair and Augmentation

최윤성,최진현,황인성,박장호,이태우 한국고분자학회 2024 한국고분자학회 학술대회 연구논문 초록집 Vol.49 No.2

Xylanase 처리가 재생섬유의 특성에 미치는 영향

최윤성,원종명 한국펄프종이공학회 1998 펄프.종이기술 Vol.30 No.3

It is well known that the recycling of pulp generates a lot of fines, and cause the hornification of fiber. Both phenomena have been contributed to a limited use of recycled fiber. Among several means which can improve the properties of recycled fiber, enzymatic treatments are considered as an effective means. Thus the effects of xylanase on the properties of recycled pulp were investigated in this study Xylanase treatment showed some refining effect at a small dosage while the fines and fibrils were reduced at higher dosage as shown in the treatment with cellulase-hemicellulase. The interesting finding is that the WRV of recycled fiber treated with xylanase was higher than that treated with the mixture of cellulase and hemicellulase. Breaking length and tear index of recycled fiber treated with xylanase were also higher.

효소처리에 의한 재생섬유의 제지적성 개선 ( Improvement of Papermaking Properties of Recycled Fiber with Enzyme )

최윤성,원종명 한국펄프·종이공학회 2001 펄프.종이기술 Vol.33 No.1

멀티밴드 레이크 수신기를 적용한 DS-UWB 시스템의 성능분석

최윤성,김수남,강동욱,김기두,Choi Yun-Sung,Kim Su-Nam,Kang Dong-Wook,Kim Ki-Doo 대한전자공학회 2004 전자공학회논문지TC (Telecommunications) Vol.41 No.12

In the paper, system is combined multiband system with DS-UWB techniques with properties including low peak-to-average power ratio, robustness to multiuser interference and excellent security. Because each sub-band is not satisfied with coherence bandwidth, rake receiver in each sub-band is applied to the Proposed system receiver. Output of rake receiver is combined by using Maximal Ratio combining technology. In this paper we mathematically analyse the BER of the DS-UWB system with singleband and multiband systems in the narrow interference channel condition and multi user interference channel condition, the simulation results show that proposed scheme is getting robuster with increasing of the number of subbands.

구름버섯의 형질전환체 Trametes versicolor MrP1에 의한 Phenanthrene의 생분해

최윤성,최형태,송홍규,Choi, Yun-Seong,Choi, Hyoung-Tae,Song, Hong-Gyu 한국미생물학회 2007 미생물학회지 Vol.43 No.4

As a model compound of PAHs (polycyclic aromatic hydrocarbons) phenanthrene has been regarded as a toxic material, mutagen and carcinogen in various animals. Biodegradation conditions of phenanthrene such as pH, temperature, shaking speed, stabilizer and cofactor of degrading enzymes were investigated with Trametes versicolor and its transformant T. versicolor MrP1 in YMG medium, minimal medium and soil microcosm. T. versicolor MrP1 can overexpress mrp gene encoding Mn-repressed peroxidase that is involved in fungal degradation. Biodegradations of phenanthrene by T. versicolor and T. versicolor MrP1 were optimally performed in conditions of weak-acid (pH 6.0), $30^{\circ}C$, shaken culture and medium containing 5 mM veratryl alcohol or tryptophan. In these optimal conditions, biodegradation of phenanthrene by T. versicolor MrP1 is 31% higher than that of wild type strain in a minimal medium for 20 days. Biodegradation of phenanthrene by T. versicolor MrP1 was also higher than that of wild type in soil microcosm. T. versicolor MrP1 can be a excellent candidate for the bioremediation of PAHs contaminated environments.

초등과학교육에서 생성형 인공지능 활용에 대한 초등 예비교사들의 인식 탐색

최윤성,정정인 이화여자대학교 교육과학연구소 2024 교육과학연구 Vol.55 No.4

The purpose of this study was to explore the perceptions of pre-service elementary teachers regarding the use of Generative Artificial Intelligence (GAI) in elementary science education. To do so, pre-service teachers enrolled at University A in Korea were recruited as research participants, and five pre-service elementary teachers voluntarily participated in the study. The researcher and the participants conducted a semi-structured interview via Zoom, during which a question-and-answer session followed the interview protocol. The interview data were then transcribed and analyzed using a qualitative text analysis method to examine the pre-service teachers’ perceptions of the educational use of GAI in science education. The findings of the study are as follows: First, the definitions and roles of elementary science education utilizing GAI, as perceived by the pre-service teachers, were classified into four domains: science knowledge— teacher, science knowledge—student, material world—teacher, and material world—student. The educational roles of GAI in elementary science education were interpreted as supporting teaching methods, increasing student interest and motivation, and providing opportunities for students to experience scientific inquiry. Second, regarding their teaching and learning experiences using GAI, all research participants indicated that they had no prior experience of using GAI in elementary science lessons. Accordingly, the pre-service teachers emphasized the importance of gaining educational experience with GAI during their pre-service teacher training period. They specifically highlighted the need for education in the following areas: cognitive domain (understanding and applying GAI, evaluating and creating with GAI), affective domain (motivation, confidence, and self-efficacy in the educational use of GAI), and ethical domain (issues related to copyright, creative works, and data reliability). Looking ahead to the application of GAI-based science lessons in real classroom settings, the pre-service teachers anticipated that it would support the development of students’ AI competencies (cognitive, affective, and ethical domains) and subject matter competencies (cognitive and affective domains). However, they also recognized the need to pay close attention to ethical issues, such as the sources of information and copyright, drawing from their own personal experiences related to GAI usage