• 한국물환경학회지
• /
• 제21권6호
• /
• pp.617-623
• /
• 2005

Forestry and agricultural land uses constitute 85% of Korea and these land uses are typically mixed in many watersheds. Biological Oxygen Demand (BOD) concentration is a primary factor for managing water qualities of the water resources in Korea. BOD loadings from diffuse sources, however, not well monitored yet. This study aims to assess BOD loadings from diffuse sources and their affecting factors to conserve quality of water resources. Event Mean Concentration (EMC) of BOD was calculated based on the monitoring data of forty rainfall events at four agricultural-forestry watersheds. Exceedence cumulative probability of BOD EMCs were plotted to show agricultural activities in a watershed impacts on the magnitude of EMCs. Prediction equation for each rainfall event was proposed to estimate BOD EMCs: $EMC_{BOD}(mg/L)=EXP(0.413+0.0000001157{\times}$(discharged runoff volume in $m^3$)+0.018${\times}$(ratio of agricultural land use to total watershed area).

• 한국농공학회지
• /
• 제32권E호
• /
• pp.59-66
• /
• 1990

Abstract The formulation of the probabilistic finite element method was briefly reviewed. The method was implemented into a computer program for frame analysis which has the same analogy as finite element analysis. Another program for Monte Carlo simulation of finite element analysis was written. Two sample structures were assumed and analized. The characteristics of the second moment statistics obtained by the probabilistic finite element method was examined through numerical studies. The applicability and limitation of the method were also evaluated in comparison with the data generated by Monte Carlo simulation.

• 한국농림기상학회:학술대회논문집
• /
• 한국농림기상학회 2001년도 춘계 학술발표논문집
• /
• pp.163-166
• /
• 2001

One of the most important factors influencing the outbreak and severity of foliar diseases is the duration of wetness from dew deposition, rainfall, or irrigation. Models may provide good alternatives for assessing leaf wetness duration (LWD) without the labor, cost, and inconvenience of making measurements with sensors.(omitted)

• 한국농림기상학회:학술대회논문집
• /
• 한국농림기상학회 2001년도 춘계 학술발표논문집
• /
• pp.93-96
• /
• 2001

Estimation of leaf wetness duration (LWD) facilitates assessment of the likelihood of outbreaks of many crop diseases. Models that estimate LWD may be more convenient and grower-friendly than measuring it with wetness sensors. Empirical models utilizing statistical procedures such as CART (Classification and Regression Tree; Gleason et al., 1994) have estimated LWD with accuracy comparable to that of electronic sensors.(omitted)

• 대한수학회보
• /
• 제56권6호
• /
• pp.1511-1524
• /
• 2019

In this paper, we investigate the uniqueness of meromorphic functions of finite order concerning sharing small functions and prove that if f(z) and ${\Delta}_cf(z)$ share a(z), b(z), ${\infty}$ CM, where a(z), b(z)(${\neq}{\infty}$) are two distinct small functions of f(z), then $f(z){\equiv}{\Delta}_cf(z)$. The result improves the results due to Li et al. ([9]), Cui et al. ([1]) and $L{\ddot{u}}$ et al. ([12]).

• 한국농림기상학회:학술대회논문집
• /
• 한국농림기상학회 2019년도 하계 학술발표초록집
• /
• pp.238-238
• /
• 2019

• 한국농림기상학회지
• /
• 제7권4호
• /
• pp.235-239
• /
• 2005

정확한 산불위험예보는 효율적인 산불감시 및 예방 활동에 기여할 수 있다. 본 연구에서는 2002년까지 운용되었던 산림청 산불위험예보시스템의 산불위험지수, 산불위험예보 등급과 실제 산불발생과의 관계를 고찰하였다. 산불위험지수와 산불발생건수의 회귀분석 결과, 비교 적 높은 설명력$(악67\%)$을 가진 반면 산불위험지수와 산불발생 피해면적과는 특별한 상관관계가 없었다. 산불위험예보 등급별로 산불발생의 차이 분석을 위해 일원분산분석을 실시한 결과, 산불발생 건수의 경우 '위험'과 '경계', '없음' 등 세 등급에 차이가 존재했으나, '경계' 와 '없음'은 구별되지 않았다. 산불발생 피해면적의 경우 '위험'과 '경계', '없음' 세 등급 모두에 있어서 차이가 발견되지 않았다. 따라서 금후에는 기존모델에 대한 산불 위험지수 위험등급조정과 더불어 산불확산지수가 고려된 통합산불위험지수 모델의 개발이 필요하다.

• 농촌지도와개발
• /
• 제22권2호
• /
• pp.175-190
• /
• 2015

Most studies examining the sub-categories of agro-industry used to access an inter-industry analysis. However, These are some limitations that researchers set sub-categories differently according to their needs. Thus, This study aims to empirically explore the agro-industry sub-categories by area of academic research on agricultural science. The National Standard Science and Technology Classification(NSSTC) codes were used to classify academic research on agricultural science. This codes were examined the sub-categories using Korean input-output statistics industry and product classification by hiring 220 departments of 37 agricultural colleges. Results showed that studies using an inter-industry analysis coincided in terms of agricultural production, but showed differences in forward and backward linkage industries and services. Forward linkages industry were clearly limited to industries in which agricultural products are inputted as raw materials. Then, in terms of services related to agriculture, Previous studies represent fields such as transport and real estate, which are not included. Moreover, Research institutions overlooked by previous studies occupy an important position.

• 농촌계획
• /
• 제20권4호
• /
• pp.193-208
• /
• 2014

This study aims to identify feasible policy direction of the 6th industrialization in agriculture based on the current agricultural and rural environment in Korea. To do so, this study employes a heckman selection model to correct a probable selection bias, utilizing the Korean agricultural census in 2010 and the agricultural statistics of farm enterprises in 2011. This study focuses on the differences of the farm and off-farm income determinants, according to conjoint types of the 6th industrialization such as Type 1 (primary+secondary+tertiary) vs. Type 2 (primary+secondary or primary+tertiary). The empirical results show Type 2 has much higher possibilities to earn farm and off-farm income in Korea, especially for farm enterprises. This study concludes with providing some policy implications reflecting rural and agricultural environment in Korea.

• 응용통계연구
• /
• 제10권1호
• /
• pp.15-27
• /
• 1997

Randomized block design (RBD) with three replication is very frequently adopted in agricultural experiments of the Rural Development Administration of Korea. Even though it works well in field trials of traditional crops, it may not accomodate trial site conditions and/or experimental environment. In this research report, we deal with two such cases. The first case is for a crop experiment in green houses. In house conditions, RBD may not be appropriate since it cannot reflect two directions of the yield gradient. So, a Latin square design is suggested as an alternative. The second case is for local field experiments of the newly-inbred rice. RBD with three replications is used without doubt for decades, even though the site layout is not appropriately shaped for the design. In this case, we suggest the RBD in two blocks with multiple replicates for control varieties as an alternative. To improve the quality of statistical experimental designs in over one-thousand agricultural trials performed annually in the Rural Development Administration, we need to re-train agricultural researchers on the design and analysis of experiments and call for concerns of Korean statisticians.