Germinability of Film-Coated Snap Bean Seed as Affected by Oxygen Diffusion Rate under Different Soil Moisture Contents

Seok Hyeon Kim,Alan G. Taylor 韓國作物學會 2004 Korean journal of crop science Vol.49 No.1

The film coated snap bean (Phaseolus vulgaris) seeds with five different coating materials treated with 3% increase in seed weight were planted at sandy loam soil controlled moisture content of 18, 19, 20 and 21 %. The oxygen diffusion rate (ODR) was calculated from the different moisture content soil. The number of normal seedlings, seedling vigor, and seedling capability in field (seed vigor x dry matter weight) were observed at 9 days after planting and compared to the changes of ODR. The germination rate and ODR were sharply decreased simultaneously in the seeds planted at 21 % soil moisture content. Seedling emergence did not occur at all as the soil moisture content increased above 22 %. Hence this value should be considered as the threshold of soil moisture content for seedling emergence. An ODR value under 20% did not influence the percent emergence significantly. The certain difference observing in the emergence at the same ODR was not related clearly to the condition of soil. So it can be assumed that the limit of soil moisture content for the emergence of snap bean was approximately 20%. The value of 18% soil moisture content may be considered as the optimum for snap bean emergence. There was close relationship between the mean value of ODR in different soil moisture contents and the emergence. The germination rates of the seeds coated with the different materials were quite different when the seeds were planted at 21 % soil moisture. Dry weight of the seedlings from film coated seeds was decreased slightly, but the germination rates were not much different from the non-treated control under relatively higher soil moisture content (21 %). Major factor lowering emergence rate was oxygen stress while film coating act as a minor constraint for snap bean sown in excess soil moisture condition.

경제변수가 생명보험 해약률에 미치는 영향

최영목 ( Young Mok Choi ),최원 ( Won Choi ) 보험연구원 2008 보험금융연구 Vol.19 No.3

본 연구는 주요 경제변수가 생명보험 종목별 및 회사별 해약률에 미치는 영향을 분석하였다. 특히, 실업률이 증가하여 보험 상품의 해약률이 증가한다는 긴급자금가설, 상승시장이자율이 상승하여 다른 금융자산에 투자하는 것이 보다 이득이 될 경우에는 보험계약을 유지하면 기회 비용이 증가하므로 해약률이 증가한다는 이자율가설, 그리고 소비자물가가 상승하여 보험금의 실질가치가 하락하면 해약률이 증가한다는 인플레이션가설을 검증하였다. 분석결과 긴급자금가설, 이자율가설, 인플레이션가설이 지지되는 것으로 나타났다. 특히, 생존보험의 해약률과 GDP성장률, 처분가능소득증가율, 실업률, 시장이자율, 소비자물가상승률 등 모든 변수 사이에 통계적으로 유의한 관계가 존재하고 모형의 설명력도 높은 것으로 나타났다. 또한 종목별 해약률 사이에 동시적 상관성이 존재할 수 있다는 점을 고려하여 SUR(seemingly unrelated regression)모형을 이용하여 추정한 결과에서는 대부분의 모형에서 해약률과 실업률, 시장이자율, 소비자물가상승률 사이에 통계적으로 유의한 관계가 존재하는 것으로 나타났다. 이러한 결과는 해약률 예측에 있어 실업률, 시장이자율, 소비자물가 등의 정보가 반드시 반영되어야 하며, 경제변수를 반영하여 예측된 해약률 정보가 상품포트폴리오 전략, 마케팅 전략, 고객관리 전략 등의 수립에 유용하게 사용될 수 있음을 시사한다. The purpose of this paper is to test the effect of principle economic variables on lapse and surrender rate for life insurance using the Korean data from the first quarter of FY1998 to the first quarter of FY2008. We employ the explanatory as the economic variables and the dependent variables as the lapse and surrender rate. We examine the following three hypotheses: (i) the emergency fund hypothesis, which asserts that the lapse rate increases when the unemployment rate grows; (ii) the interest rate hypothesis, which suggests that the lapse rate grows when the market interest rate increases because keeping insurance contracts cause the opportunity cost to increase and (iii) the inflation hypothesis, which claims that the lapse rate grows when the rise in consumer price index decreases the real value of claim amount. The empirical results support the emergency fund hypothesis, the interest rate hypothesis, and the inflation hypothesis. In particular, this study indicates that there is a statistically significant relationship between the lapse rate and GDP growth rate, the growth rate of disposal income, unemployment rate, market interest rate, and the growth rate in consumer prices and that the explanation power of the model is high as indicated by the high adjusted R squared value. Taking into account that there could be the contemporaneous correlation among the types of life insurance products, we also use the seemingly unrelated regression (SUR) model. The empirical results show that there is a statistically significant relationship between the lapse rate and unemployment rate, market interest rate, and the growth rate in consumer prices. Our empirical findings suggest that the information of unemployment rate, market interest rate and consumer price index should be reflected in estimating the lapse rate, and represent that the lapse rate estimated using economic variables could be used in establishing the portfolio strategy, marketing strategy and client management strategy.

벼 품종간 엽 생장속도 차이가 생육 및 수량에 미치는 영향

구본일 ( Bon Il Ku ),강신구 ( Shin Ku Kang ),상완규 ( Wan Gyu Sang ),이민희,박홍규 ( Hong Kyu Park ),김영두 ( Young Doo Kim ),이점호 ( Jeom Ho Lee ) 전북대학교 농업과학기술연구소 2014 농업생명과학연구 Vol.45 No.1

This experiment was conducted to compare emergence rate on main culm leaf among cultivars having similar heading date and to evaluate the effects of leaf emergence rate on growth and yield of rice. During 2009~2011, five early maturing rice cultivars(Unbong, Namweon, Jinbu, Unkwang and Sangju), four middle maturing rice cultivars(Seojin, Ganckeok, Hwayeong and Kwangan) and four middle-late maturing rice cultivars(Daecheong, Ilpum, Ilmi and Nampyeong) were transplanted at three different dates from May 16 to June 15 in Iksan region. Number of leaf emerged on main culm increased as heading date delayed, but some rice cultivars having similar heading date showed noticeable difference in emerged leaf number. In transplanting on May 16, the early maturing cultivar, Jinbu, had 1.2 leaf more than Unbong which had similar heading date. Similarly middle maturing cultivar, Kwangan, had 1.6 and 1.4 more emerged leaf than Hwayoung and Gancheok, respectively. As transplanting date delayed, leaf number emerged on main culm decreased in general dates, but some cultivars get increased leaf number in late transplanting dates. Consequently, it was difficult to get a constant rate in leaf number corrected with transplanting date. Cultivars having more emerged leaf number generally had increased dry weight at heading stage, and it is postulated that the increase in dry weight was more contributed by prolonged growth duration than by leaf emergence rate. In transplanting on May 16, early maturing cultivars, Unbong, Namweon and Jinbu showed significant yield decrease compared to yield in transplanting on June 15 because of high temperature during ripening stage, but Unkwang showed least reduction in yield. In transplanting on June 15, middle-late maturing cultivars, yield of Daecheong showed significantly reduced compared to that in transplanting on June 1 because of low temperature during ripening stage, but Ilmi and Nampyeong showed slight reduction in yield.

The link between interest rates and exchange rates: do contractionary depreciations make a difference?

Marcelo Sanchez 한국국제경제학회 2008 International Economic Journal Vol.22 No.1

This paper revisits the relationship between interest rates and exchange rates using a simple model that incorporates the role of exchange rate pass-through into domestic prices and distinguishes between cases of expansionary and contractionary depreciations. The model results show that the correlation between exchange rates and interest rates, conditional on an adverse risk premium shock, is negative for expansionary depreciations and positive for contractionary ones. For this type of shock, interest rates are found to be raised to prevent the contractionary effect of a depreciation regardless of whether the latter effect is strong or mild. Interest rates are predicted to eventually rise in response to an adverse net export shock in contractionary depreciation cases, and to be lowered in the case of expansionary ones.

달러 인덱스 변동이 주요국 환율 변동에 미치는 영향에 관한 연구 - 아시아와 남미의 신흥국을 중심으로 -

김연준 한국국제금융학회 2014 국제금융연구 Vol.4 No.2

People around the world prefer safe assets with the financial crisis starting from 2008. Preference on safe assets makes increase demand of dollar. And, this affects exchange rate for emerging countries. Exchange rate is a very important factor that affects profit in a company. And, this also affects economic growth in one country. Many economists use dollar index to measure whether dollar has strong trend or weak trend. And, many other factors affect volatility of exchange rate: economic growth, interest rate, money supply, prices, economic and political factors, and foreign direct investment. This paper investigates whether changes in dollar index affect emerging countries’ exchange rates using data recent one year. We use the Granger-causality analysis. Our results show that dollar index affects exchange rate of Argentina, Brazil, Chile, Indonesia, Malaysia, Mexico, Philippines, Singapore. With this result, we find that dollar index affect emerging countries’ exchange rate which are located in Southern America and Asia. This is caused by weakened emerging market’s currency which is turn to be weakened from the strong point. Further researches are needed to investigated such as changes in trend of consumers and changes in stock market under the strong dollar. 2008년 미국 발 금융위기가 도래하자 금융 불안 급습으로 전 세계는 달러화와 같은 안전자산에 대한 선호도가 높아졌다. 안전자산 선호 현상은 달러화에 대한 수요를 급증하게 하고 이는 상대적으로 신흥국 환율에 여러모로 영향을 미치게 된다. 환율은 기업의 채산성에 영향을 미치는 여러 가지 요인들 가운데 중요한 변수로 인식되고 있으며 각국의 환율 하락은 각국 경제에서 수출 기업들의 채산성을 하락하게 만들고 이는 한 기업의 이윤 추구에 부정적인 영향을 줄 뿐만 아니라 국가 전체의 경제에도 좋지 않은 영향을 주게 된다. 여러 단체에서 달러화가 강세를 보이는지 아니면 약세를 보이는지를 파악해 보는 지표로 달러 인덱스를 주로 사용하고 있다. 그리고 환율 변동에 영향을 미치는 변수로는 한 국가의 경제성장율, 금리, 통화량, 물가, 뉴스, 정치·경제적 요인들, 외국인 자금 등이 있다. 본 연구에서는 달러 인덱스 변화가 여타 국가들의 통화에 어떠한 영향을 미치는지를 최근 1년간 데이터를 가지고 연구한다. 특히 신흥국의 데이터를 가지고 분석을 한다. 연구결과 달러 인덱스는 아르헨티나, 브라질, 칠레, 인도네시아, 말레이시아, 멕시코, 필리핀, 싱가포르의 환율에 각각 영향을 미치는 것으로 나타났다. 이는 달러 인덱스 변화는 남미 및 동남아시아에 위치한 신흥국의 환율에 영향을 미치는 것을 확인해 볼 수 있다. 이는 달러 약세로 강세를 이어온 신흥국 통화가 일반적으로 약세로 전환했기 때문이다.

꿀벌 유충 독성시험 사육 plate 배치 및 유충 배설물 흡수에 따른 우화율 및 기형률 비교

김주영,전경미,김보선,윤창영,오진아,박홍현,최용수 한국농약과학회 2022 농약과학회지 Vol.26 No.3

Recently, pesticide is considered to be one of the major factors in the decline of the honey bee colonies. In this regard, it is important to evaluate the toxic effects on bee larvae that underlie honey bee colony health and survival. The honey bee larval toxicity test is presented in the OECD guidelines, and in order to satisfy the validity of the test, the adult emergence rate should be 70% or more in controls. Recent studies have proposed the methods to transfer the larvae to a new plate lined with Kimwipes in the pupal stage or to set a 48-well culture plate vertically. However, the specific data on the emergence and deformation rates has not yet been reported. Therefore, in this study, we examined the effect of absorption of larval feces using Kimwipes and/or rearing plate position (vertical and horizontal) in the pupal stage on the adult emergence and deformation rates. The test group consisted of four groups as follows: 1) the non-covered and horizontally oriented groups (NHG), 2) the non- covered and horizontally oriented groups using Kimwipes tissues to absorb larval feces (NHK), 3) the covered and vertically oriented groups (CVG), 4) the covered and vertically oriented groups using Kimwipes tissues to absorb larval feces (CVK). Each test group was performed with 6 replicates (36 larvae per replicate). As a result, the adult emergence rates of all groups were approximately 90%, and there were no significant differences. The adult deformation rates of NHG, NHK, CVG, and CVK were 21.2 ± 3.3%, 18.6 ± 3.0%, 8.7 ± 0.9%, and 2.1 ± 1.0%, respectively. Therefore, when the larvae were transferred to a new plate lined with Kimwipes and the plate was set vertically in the pupal stage, the adult deformation rate could be minimized. In the future, this rearing method can be useful for conducting studies of lethal effects, and sub-lethal effects such as deformations when pesticides are exposed to the honey bee larval stage.

흰점박이꽃무지(Protaetia brevitarsis) 성충의 우화되는 시기의 표준화

최인학,최성업,손진성,정태호,Choi, In-Hag,Choi, Sung-Up,Son, Jin-Sung,Chung, Tae-Ho 한국환경과학회 2021 한국환경과학회지 Vol.30 No.2

This study was conducted to determine and to standardize the time of emergence of Protaetia brevitarsis adults, through four breeding experiments, including one which selected the dominant individuals of Protaetia brevitarsis. The breeding experiments were divided into two groups with hibernating and non-hibernating Protaetia brevitarsis by placing 100, 150, 200, 250 and 300 Protaetia brevitarsis in each breeding box (50 cm × 35 cm × 15 cm) filled with 12 L of fermented sawdust. Breeding tests were with four replicates each for 3 months. The test period was classified into four stages: Exp. 1 (Sep 1, 2019 to Nov 30, 2019), Exp. 2 (Dec 1, 2019 to Feb 29, 2020), Exp. 3 (Mar 1, 2019 to May 31, 2020) and Exp. 4 (Jun 1, 2020 to Aug 31, 2020). The survey items included average dead number, average emergence number, average mortality, and average emergence rate. In Exp. 1 and 2, the changes in Protaetia brevitarsis adults were similar. In Tables 1 and 2, the allegorical changes of adult white-spotted flowers were similar. In addition, the average dead number, average emergence number, average mortality, and average emergence rate showed better results in the hibernation state than in both Exp. 1 and 2. Exp. 3 and 4 showed a pattern of change different from the results of Exp. 1 and 2 and these characteristics were superior in the hibernation states compared to the non-hibernation states. In conclusion, this result was found to be most appropriate as a standardization of the emergence time of 200 Protaetia brevitarsis treatments through four breeding experiments in the hibernating state.

Optimum Harvest Time for High Quality Seed Production of Sweet and Super Sweet Corn Hybrids

Lee Suk Soon,Yun Sang Hee,Seo Jung Moon The Korean Society of Crop Science 2004 Korean journal of crop science Vol.49 No.5

The production of sweet (su) and super sweet corns (sh2) has been economically feasible in Korea in recent years. Major factors limiting super sweet corn production are low germination and low seedling vigor. Since seed quality is closely related to seed maturity, the optimum harvest time for the seed production of sweet and super sweet corns was studied and the quality of seeds with varying maturities was investigated in 2001 and 2002 cropping seasons. The parents of the sweet corn seeds were Hybrid Early Sunglow and 'Golden Cross Bantam 70' and those of super sweet corn were Xtrasweet 82 and 'For­tune'. Seeds were harvested at 21, 28, 35, 42, 49, and 56 days after silking (DAS). As the seeds developed, seed weight of sweet corn increased and the seed moisture content decreased faster than that of super sweet corn. Germination rates of sweet corn seeds harvested 21 and 28 DAS at $25^{\circ}C$ and emergence rates in the cold soil test were significantly lower than those of seeds harvested after 42 DAS in both years. Although the germination rates of super sweet corn seeds with varying maturities showed similar patterns as sweet corn seeds at $25^{\circ}C$, the emergence rate of super sweet corn seeds in cold soil test continuously increased with seed maturity. This suggests that seed quality of super sweet corn should be tested in a cold soil test to estimate field emergence. As the seeds developed, leakage of total sugars and electrolytes from the both sweet and super sweet corn seeds decreased up to 42 or 49 DAS. The $\alpha-amylase$ activities of both sweet and super sweet corn seeds increased with seed maturity from 21 to 35 or 49 DAS depending on genotype and year. The optimum harvest time for the seed production of sweet corn was 42 DAS and 49 DAS for super sweet corn considering emergence rate and plumule dry weight in the cold soil test, leakage of sugars and electrolytes from the seeds, and $\alpha-amylase$ activity.

Optimum Harvest Time for High Quality Seed Production of Sweet and Super Sweet Corn Hybrids

Suk Soon Lee,Sang Hee Yun,Jung Moon Seo 韓國作物學會 2004 Korean journal of crop science Vol.49 No.5

The production of sweet (su) and super sweet corns (sh2) has been economically feasible in Korea in recent years. Major factors limiting super sweet corn production are low germination and low seedling vigor. Since seed quality is closely related to seed maturity, the optimum harvest time for the seed production of sweet and super sweet corns was studied and the quality of seeds with varying maturities was investigated in 2001 and 2002 cropping seasons. The parents of the sweet corn seeds were Hybrid Early Sunglow and 'Golden Cross Bantam 70' and those of super sweet corn were Xtrasweet 82 and 'For-tune'. Seeds were harvested at 21, 28, 35, 42, 49, and 56 days after silking (DAS). As the seeds developed, seed weight of sweet corn increased and the seed moisture content decreased faster than that of super sweet corn. Germination rates of sweet corn seeds harvested 21 and 28 DAS at 25~circC and emergence rates in the cold soil test were significantly lower than those of seeds harvested after 42 DAS in both years. Although the germination rates of super sweet corn seeds with varying maturities showed similar patterns as sweet corn seeds at 25~circC , the emergence rate of super sweet corn seeds in cold soil test continuously increased with seed maturity. This suggests that seed quality of super sweet corn should be tested in a cold soil test to estimate field emergence. As the seeds developed, leakage of total sugars and electrolytes from the both sweet and super sweet corn seeds decreased up to 42 or 49 DAS. The α-amylase activities of both sweet and super sweet corn seeds increased with seed maturity from 21 to 35 or 49 DAS depending on genotype and year. The optimum harvest time for the seed production of sweet corn was 42 DAS and 49 DAS for super sweet corn considering emergence rate and plumule dry weight in the cold soil test, leakage of sugars and electrolytes from the seeds, and α-amylase activity.

A Study of the Relationship between Renminbi Exchange Rates and Chinese Stock Prices

Robert W. Rutledge,Khonkar E. Karim,Chensheng Li 한국국제경제학회 2014 International Economic Journal Vol.28 No.3

This study examines the relationship between Chinese renminbi (RMB) exchange rates and Chinese stock prices over the full study period of 20 July 2001 to 21 July 2011. The study also investigates the relationship between the exchange rate and ten industry-specific indices. Also examined is the effect of two specific events on the ‘exchange rate/stock price’ relationship: (1) the easing of exchange rate controls, and (2) the 2008 start of the global financial crisis. A long-run cointegration relationship is found during the full study period between exchange rates and the Shanghai A-share prices, and for nine of ten industry indices. Granger causality in one direction (i.e., from exchange rates to stock prices, or vice versa) or both directions is found for four of the industry-specific indices. Interestingly, both a long-run cointegration relationship and Granger causality are only found during the most volatile period of managed exchanged rates before the global financial crisis. Implications for Chinese monetary policy makers and global investors are provided.