침엽수 조림지에서의 잔존림분밀도에 따른 임목생장 비교에 관한 연구 ( The Comparison of Tree Growth by the Residual Stand Density in Artificial Coniferous Forests )

강성기,김완수,이원섭,김지홍 한국산림바이오에너지학회 2001 산림바이오에너지 Vol.20 No.2

The Changes of Understory Vegetation by Partial Cutting in a Silvopastoral Practiced Natural Deciduous Stand

강성기,김지홍 한국산림과학회 2008 한국산림과학회지 Vol.97 No.2

Recognizing the importance of the multi-purpose management of natural deciduous forest, thisstudy was carried out to implement the partial cutting for stand regulation to examine agroforestry practiceas well as other concurrent forest resource production, and to investigate the changes in stand characteristicsand understory vegetation in a silvopasture practiced natural deciduous stand in the Research Forest ofwere performed in the unmanaged natural deciduous stand in order to improve the growing condition,especially light condition, for introducing some comercial herbaceous plants on the forest floor toestablish agroforestry and/or silvopastoral system. Dominated by Quercus varibilis Blume (50.5%) andQuercus dentata Thum. ex Murray (42.6%), eight tree species were composed of the study forest, includingpoles of Pinus desiflora Siebold & Zucc and sapling of Pinus Koraiensis (13 tree species, 12 shrub species, 58 herbaceous species, and 4 wody climbers) vascular plant specieswere observed in study site after partial cutting treatments, while that of before partial cutting was 53species (14 tree species, 8 shrubs species, 30 herbaceous species, and 1 woody climbers). The proportionof life form spectra in plot B was Mi (28.4%)-Na (23.0%)-Ge (17.5%)-Ch (10.8%)-He (9.5%)-MM (6.7%)-Th (4.1%). No statistically significant diferences were observed in changes of life form spectra fromscratching for forage sowing made plants invade easily on the forest floor, and light partial cuting (LPC)plot (500 stems/ha) had much higher number of undersory species than those of heavy partial cutting (HPC)plot (310 stems/ha) and control plot (1,270 stems/ha).

노인을 위한 신체활동 설문지의 신뢰도와 타당도 검증

강성기 龍仁大學校 體育科學硏究所 2009 體育科學硏究論叢 Vol.19 No.1

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피하지방 측정 Caliper의 신뢰도 및 타당도 분석

강성기,조재혁 용인대학교 국제스포츠과학연구원 체육과학연구소 2008 體育科學硏究論叢 Vol.18 No.1

The purpose of this study is to examine the quality of the skinfold calipers by practically measuring the subcutaneous fat in the body parts. The experiment was conducted on the 60 male students in middle schools. The 3 types of calipers of Harpenden, Skyndex and Lange are used to measure the 8 parts, and then I calculated the reliability, the validity and compared the difference in the measurements between the types with the result. The Mean and the standard deviation of all the result of the experiment were calculated by SPSS v. 15.0 for Windows. With the data, I examined the difference of the reliability (represented by Pearson's r) between the types, and that of validity with the correlation coefficients (represented by Pearson's r) by a part. As well, I compared the differences of the measurements by a part between the types using the One-way RM(3) ANOVA. I found out the followings through the analysis. First, the reliability of each type was estimated through the repeated measurement of each part with Harpenden, Skyndex and Lange. The result showed that all the types have the reliability over r=.98. Second, the correlation between the types of Harpenden, Skyndex and Lange in the measurements of each part showed generally over r=.97. Third, there is a significant difference (p<0.01) in the mean of the repeated measurements of skinfold in some parts including Triceps, Biceps, Subscapular, Front thigh and Medial calf between Harpenden and Skyndex. Forth, there is not a significant difference (p>0.05) in the mean of the repeated measurements in other parts, including Iliac crest, Supraspinale and Abdominal between Harpenden and Skyndex. Fifth, there is a significant difference (p<0.01) in the average of the repeated measurements in all the parts between Harpenden and Lange. I suggest the followings based on the result. Therefore the type of the caliper used should be noted in the records of measurements with the caliper.

點鳳山一帶 天然闊葉樹林의 地形的 位置에 따른 群集 構造的 分析(Ⅱ)

姜聲基 江原大學校 山林科學大學 演習林 2000 學術林硏究誌 Vol.20 No.-

디스플레이산업의 과거, 현재 그리고 미래

강성기 한국공업화학회 2013 한국공업화학회 연구논문 초록집 Vol.2013 No.-

Current Status and Future Outlook of OLED Technology

강성기 한국공업화학회 2014 한국공업화학회 연구논문 초록집 Vol.2014 No.0

산업계에서 바라보는 바람직한 Display 재료의 산학연 연구 방향

강성기 한국공업화학회 2020 한국공업화학회 연구논문 초록집 Vol.2020 No.-

학회 산학연 협력위에서 2020년 춘계 학회에서 논의될 산업 지향적 기술개발을 위한 R&D토론회 에서의 발제 발표로서 그 주요 내용은 Display 재료 개발 동향 공유와 함께 새로운 개념의 Display 개발을 위한 재료의 개발 요구 특성과 이를 만족시키기 위한 바람직한 산학연 협업에 대한 의견을 제시하고자 함.

체지방률 검사를 통한 초음파 측정기기의 타당도 검증

강성기,이미영,김용익 한국체육측정평가학회 2019 한국체육측정평가학회지 Vol.21 No.3

The purpose of this study is to verify the validity of ultrasonic measuring device through body fat percentage test. To achieve this goal, validity tests were performed using the measured values of Dual Energy X-ray Absorptiometry known as the reference method. 58 university students were participating in the study from Gyeonggi-do. Height and weight were measured as well as Body fat percentage using the portable ultrasound device and Dual Energy X-ray Absorptiometry. For data processing, the average and standard deviation of the data were calculated by using SPSS 25.0 program and MedCalc program. Correlation analysis (r) and Bland & Altman were performed to examine the validity of the ultrasound device. In addition, the interpolation and slope were presented in the Bland & Altman results and the mean absolute percentage errors was presented for the verification of accuracy. In male students, there was a high correlation between the ultrasonie device and Dual Energy X-ray Absorptiometry in male (r=.92) and females (r =.71). The results of the Bland & Altman analysis showed that the confidence interval was stable and that the agreement was high. In the case of male students -13.4 ~ 2.9, the confidence interval range was shown. the mean absolute percentage errors was 28.6%. In the case of women the confidence interval ranged from -8.0 to -1.3, with mean absolute percentage errors of 17.2%. As a result, it was confirmed that the body fat rate validity between the ultrasonic measuring device and Dual Energy X-ray Absorptiometry was high. 본 연구는 체지방률 검사를 통한 초음파 측정기기의 타당도 검증에 목적이 있다. 이 목적을 달성하기 위하여 준거방법으로 알려진 이중에너지 방사선 흡수법의 측정값을 이용하여 타당도 검증을 실시하였다. 연구 참여자는 경기도지역 대학생 58명을 대상으로 하였다. 측정은 신장과 체중 그리고 초음파, 이중에너지 방사선 흡수법을 통해서 체지방률을 측정하였다. 자료처리는 SPSS 25.0 program과 MedCalc program을 이용하여 자료의 평균과 표준편차를산출 하였으며, 타당도 검증을 위하여 상관분석(r)과 Bland & Altman Plot을 실시하였다. 또한, 정확성 검증을 위하여 Bland & Altman 결과에 절편과 기울기를 제시하였으며 절대오차율을 제시하였다. 남학생의 경우 초음파 측정기기와 이중에너지 방사선 흡수법 간의 높은 상관관계를(r=.92) 보였고, 여자도 높은 상관관계가 나타냈다(r=.71). Bland & Altman을 이용한 결과 신뢰구간이 안정적으로 나타났으며, 일치성이 높다고 검증 되었다. 남학생의 경우-13.4 ~ 2.9 신뢰구간 범위를 나타냈으며 절대오차율은 28.6%로 나타냈다. 여자의 경우 -8.0 ~ -1.3 신뢰 구간 범위를 나타냈으며 절대오차율은 17.2%로 나타냈다. 결과적으로 초음파 측정기기와 이중에너지 방사선 흡수법 간의 체지방률 타당도는 높은 것을 확인할 수 있었다.

The Effects of Silvopastoral Practice on Changes of Understory Vesetation in a Japanesr Larch(Larix kaempferi) Plantation

강성기,김지홍 한국산림과학회 2007 한국산림과학회지 Vol.96 No.2

This study was conducted to investigate the efects of thining on changes in standcharacteristics and understory vegetation in a silvopasture practiced Japanese larch plantation in theResearch Forest of Kangwon National University, Korea. Thre different thinning intensities (64%, 35%,and control) were applied. Before and after thinning, the understory plant species increased its number from48 (7 tre species, 7 shrubs species, 28 herbaceous species, and 6 wody climbers) to 10 (1 tree species,the forest floor, and plot A (325 stems/ha) had much higher number of undersory species than those of plotB (575 stems/ha) and control plot (1,150 stems/ha). In three years after thinning, understory abovegroundbiomass (kg/ha) of herbs were 523 for control, 1,230 for plot B, and 1,288 for plot A. The canopy coveragehad remarkable influence on the understory biomass production, resulting in relatively small amount ofherbage production on control plot. The diferences were statisticaly significant between thinned plots and