• 한국산림과학회지
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• 제111권4호
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• pp.583-593
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• 2022

우리나라의 임목수확작업은 작업자의 고령화 및 고임금의 문제에 직면하고 있으며, 위기 개선을 위해 작업체계 개선 및 고성능 임업기계를 이용한 안정성 확보 등이 필요하다. 따라서 본 연구는 경사 35% 이상의 지역에서 타워야더와 프로세서를 기반으로 한 목재수확시스템을 적용할 때 다공정작업과 단공정작업의 생산성을 비교하며, 작업시스템의 비용절감 효과를 분석하고자 하였다. 국립산림과학원 광릉시험림 15임반 모두베기 지역을 대상으로 전목(가선)집재작업을 실시하였으며, 다공정과 단공정시스템의 생산성 및 비용을 분석하였다. 다목적집재장비를 이용한 단공정시스템은 타워야더와 프로세서를 이용한 다공정시스템에 비해 cycle당 집재본수가 1본/cycle 더 많아 집재작업 생산성은 약 1.5 m³/PMH (Productive Machine Hour; PMH)이, 조재작업은 약 1.6 m³/PMH이 더 높게 산출되었다. 다목적집재장비를 이용한 단공정(36,113원/m³)시스템은 다공정작업(41,065원/m³)시스템 보다 약 12.1%의 비용이 절감되었다. 또한 유휴시간(Idle time) 감소에 따라 단공정 및 다공정시스템 비용은 각각 최대 22.6%와 15.9%가 절감되었다.

• Ocean and Polar Research
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• 제39권3호
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• pp.205-211
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• 2017

This paper seeks to provide a dynamic analysis of a 150 ton winch based on ocean environmental data. The winch model that was subjected to analysis was modeled from CAD to each subsystem by the commercial software DAFUL. The winch model has tree brake systems (disk brake, band brake and ratchet brake). The rotation motion of the motor and contact elements of the brake are applied to the winch model in order to analyze its dynamic characteristics. In addition, a crane-barge was modeled to apply ocean environmental data. The motion data of the crane-barge was produced by means of the RAO(Response Amplitude Operator) of the barge and wave spectrum. The reaction force of the translational joint was measured instead of the tension of the cable. The brake performance of the winch was produced and assessed based on the operating motion of the crane-barge.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1627-1627
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• 2001

In this study, a newly constructed optical measurement system, whose main components were a parametric tunable laser and a near infrared photoelectric multiplier, was applied to detection of the information for the inside of Satsuma mandarin using time-of-flight near infrared spectroscopy (TOF-NIRS). The combined effects on the time resolved profile of sample diameter, sugar content, the wavelength of the laser beam, and the detection position of transmitted light were investigated in detail. The samples used were Satsuma mandarin (Citrus unshu $M^{ARC}$.) (location: Wakayama, Japan) having the diameters of 50-84 mm. The sugar content measured by a refractometer varied from 9.9 to 16.3 Brix%. Equator of sample was irradiated vertically with the pulsed laser, and transmitted output power was measured on the restricted position of the equator using the optical fiber cable. The sampling time and the number of averaging the output power were 100 ns and 100 times, respectively. The variation of the attenuance of peak maxima At, the time delay of peak maxima t and the variation of full width at half maximum w were strongly dependent on the detection position and the wavelength of the laser beam. At, t and w increased gradually as the sample diameter increased to be much absorbed and vigorously scattered. On the other hand, each optical parameter had a tendency to increase as the sugar content increased. Such behavior was remarkable when the transmitted light was detected at the side face of a sample. When we apply TOF-NIRS to detection of the information for the inside of fruit with high moisture content like Satsuma mandarin, it is very important to give attention to the difference in the scattered light within tissues and the semi-straightly propagated light. Furthermore, we tried to express the resulting phenomena by using a model samples composed of water, sucrose, and milk. The variation of the time resolved profile is strongly governed by the combination of the light absorption component, scattering medium, and refractive index.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1626-1626
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• 2001

In this study, a newly constructed optical measurement system, whose main components were a parametric tunable laser and a near infrared photoelectric multiplier, was applied to detection of the information for the inside of Satsuma mandarin using time-of-flight near infrared spectroscopy (TOF-NIRS). The combined effects on the time resolved profile of sample diameter, sugar content, the wavelength of the laser beam, and the detection position of transmitted light were investigated in detail. The samples used were Satsuma mandarin (Citrus unshu $M_{ARC}$.) (location: Wakayama, Japan) having the diameters of 50-84 mm. The sugar content measured by a refractometer varied from 9.9 to 16.3 Brix%. Equator of sample was irradiated vertically with the pulsed laser, and transmitted output power was measured on the restricted position of the equator using the optical fiber cable. The sampling time and the number of averaging the output power were 100 ns and 100 times, respectively. The variation of the attenuance of peak maxima At, the time delay of peak maxima $\Delta$t and the variation of full width at half maximum Δw were strongly dependent on the detection position and the wavelength of the laser beam. At, $\Delta$t and $\Delta$w increased gradually as the sample diameter increased to be much absorbed and vigorously scattered. On the other hand, each optical parameter had a tendency to increase as the sugar content increased. Such behavior was remarkable when the transmitted light was detected at the side face of a sample. When we apply TOF-NIRS to detection of the information for the inside of fruit with high moisture content like Satsuma mandarin, it is very important to give attention to the difference in the scattered light within tissues and the semi-straightly propagated light. Furthermore, we tried to express the resulting phenomena by using a model samples composed of water, sucrose, and milk. The variation of the time resolved profile is strongly governed by the combination of the light absorption component, scattering medium, and refractive index.

• 지식경영연구
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• 제20권3호
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• pp.155-171
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• 2019

In the entertainment industry which has great uncertainty, it is essential to predict public preference first. Thanks to various mass media channels such as cable TV and internet-based streaming services, the reality audition program has been getting big attention every day and it is being used as a new window to new entertainers' debut. This phenomenon means that it is changing from a closed selection process to an open selection process, which delegates selection rights to the public. This is characterized by the popularity of the public being reflected in the selection process. Therefore, this study aims to implement a machine learning model which predicts the winner of , which has recently been popular in South Korea. By doing so, this study is to extend the research method in the cultural industry and to suggest practical implications. We collected the data of winners from the 1st, 2nd, and 3rd seasons of the Produce 101 and implemented the predictive model through the machine learning method with the accumulated data. We tried to develop the best predictive model that can predict winners of by using four machine learning methods such as Random Forest, Decision Tree, Support Vector Machine (SVM), and Neural Network. This study found that the audience voting and the amount of internet news articles on each participant were the main variables for predicting the winner and extended the discussion by analyzing the precision of prediction.

• 한국산림과학회지
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• 제107권3호
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• pp.266-277
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• 2018

본 연구에서는 모두베기 작업지에서 2중 무선 클램프 반송기를 적용한 굴삭기 기반 타워야더의 집재작업 생산성 및 비용을 분석하였다. 집재작업의 생산성은 $6.2m^3/SMH$(기계이용률 80.4%)이고, 비용은 $13,705won/m^3$으로 나타났다. 이 결과는 기존 연구결과에 비해 최대 집재거리가 길었음에도 불구하고 가선설치용 견인줄(Straw line)을 이용한 가선설치로 집재선 가선설치 시간이 단축되었으며, 2중 무선 클램프 반송기 적용으로 인해 생산성이 향상되고 비용이 절감된 것으로 나타났다. 또한, 원료재급과 임목축적 $137m^3/ha$ 기준으로 집재작업의 생산재적에 따른 최소작업량과 최소작업면적은 리기다소나무의 경우 각각 $558.3m^3$ 및 4.1 ha였고, 신갈나무의 경우 $433.7m^3$ 및 3.2 ha로 나타났다. 향후, 다양한 작업현장에서 집재기계별 최소작업량 및 최소작업면적에 관한 데이터를 구축하면, 집재작업에 효율적인 집재기계를 선정할 수 있을 것으로 판단된다.

• 한국산림과학회지
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• 제106권2호
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• pp.204-212
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• 2017

중장비를 이용한 임목생산작업은 산림 내 토양교란을 유발하며, 산림토양은 토양침식에 취약한 구조를 가지게 된다. 임목생산방법 및 장비에 따라 토양교란 유형 및 토성 변화 정도는 다르게 나타난다. 따라서 이 연구에서는 국내에서 이루어지고 있는 우드그랩을 이용한 단목생산방법과 스윙야더를 이용한 전목생산방법에 따른 토양교란 영향을 평가하였다. 이를 위하여 토양교란 유형은 시각적 평가방법을 이용하여 분류하였으며, 교란 유형에 따른 토양의 물리성 변화는 토양시료캔에 의한 샘플링 방법을 이용하였다. 단목과 전목생산작업지에서 관찰된 극심한 교란(deep disturbance)과 토양답압(compacted) 유형은 각각 48%와 23%로 나타났다. 또한, 임목생산작업에 따른 토양의 물리성 변화는 중장비 차량이 통행한 곳에서 차이가 발생하였다. 반면 차량 통행과 관련 없는 토양교란 유형에서는 임목수확작업 전 후의 토양의 용적밀도 및 공극률은 통계적으로 차이가 없었다. 이 연구를 통해 산림 내에서 중장비의 통행으로 인하여 주로 토양 교란 및 훼손이 발생함을 알 수 있었다.