• Journal of Forest and Environmental Science
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• 제33권3호
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• pp.172-186
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• 2017

The effects of application of fuel-reduction treatment in wildfire management has not been tested in dry forests of Ghana. Therefore, the short-term ecological effects of prescribed burning and hand thinning treatments followed by experimental wildfire were investigated in degraded forests and Tectona grandis forest plantations in two forest reserves of different levels of dryness in Ghana. The results showed that more trees were killed in prescribed burning (average of 41% in degraded forest and 18% in plantations) than hand thinning (7.2% in degraded forests and 8% in plantation). More tree seedlings were also killed in prescribed burning (72%) than hand thinning (47%). The mortality of trees and seedlings were greater in Worobong South forest, a less dry forest reserve than the Afram Headwaters forest, a drier forest reserve. Fuel treatment especially prescribed burning compared to the control reduced wildfire effects on forest canopy particularly in the less dry forest and tree mortality especially in the drier forest. Prescribed burning temporarily increased pH, exchangeable potassium (52%) and available phosphorus (82%) in the surface soils of the entire plots. The two fuel treatment methods did not have much influence on basal area, organic matter and total nitrogen. Nevertheless, they were able to reduce the adverse wildfire effects on soil pH, exchangeable potassium, available phosphorus, organic matter and total nitrogen concentrations. Fuel treatments therefore have potential application in dry forest management in Ghana due to their ability to retain important forest ecological traits after a wildfire incidence.

• 한국양식학회지
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• 제9권2호
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• pp.109-115
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• 1996

우리나라 연안성에서 가장 중요한 양식대상종의 하나인 참전복의 표식 방류효과에 관한 조사는 보고된 바 없는 실정이다. 따라서 본 연구는 우리 배양장에서 자체 생산된 참전복의 표지 방법별 효과를 검토하고, 방류효과를 구명함으로서 연안 자원의 증강을 도모 하고자 1994년 11월 10일 부터 1995년 3월 30일까지 조사한 결과를 요약하면 다음과 같다. 1. 참전복의 표지 및 표시 방법별 효과는 Al-teco에 의한 표지 부착이 가장 좋았다. 2. 실내 사육에 의한 표지의 탈락 및 폐사율은 각각 $6.7\%$ 및 $8.3\%$였고, 표지에 의한 폐사는 없었다. 3. 실내 사육 및 방류한 표지 개체는 실험 개시시 각구 공히 평균각장 및 전중량이 1.0 cm, 0.092 g 이던 것이 실험종료시에는 각각 1.80cm, 0.74 g, 1.68 cm, 0.68 g으로 성장하였다. 4. 재포된 모든 개체의 분포 중심 수심은 2.6m 였다. 재포된 모든 개체의 평균 이동 거리는 2.6m 였다. 6. 어획사망계수, 자연사망계수 및 전사망계수의 추정치는 각각 0.0195, 0.4652, 0.4847였다.

• Journal of Forest and Environmental Science
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• 제34권6호
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• pp.419-428
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• 2018

Spatial point-patterns analyses were conducted to provide insight into the ecological process behind competition and mortality in two lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) stands, one in the Lower Foothills, and the other in the Upper Foothills natural subregions in the boreal forest of Alberta, Canada. Spatial statistical tests were applied to live and dead trees and included Clark-Evans nearest neighbor statistic (R), nearest neighbor distribution function (G(r)), and a variant of Ripley's K function (L(r)). In both lodgepole pine plots, the results indicated that there was significant regularity in the spatial point-pattern of the surviving trees which indicates that competition has been a key driver of mortality and forest dynamics in these plots. Dead trees generally showed a clumping pattern in higher density patches. There were also significant bivariate relationships between live and dead trees, but the relationships differed by natural subregion. In the Lower Foothills plot there was significant attraction between live and dead tees which suggests mainly one-sided competition for light. In contrast, in the Upper Foothills plot, there was significant repulsion between live and dead trees which suggests two-sided competition for soil nutrients and soil moisture.

• 한국응용곤충학회지
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• 제2권
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• pp.22-26
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• 1963

1) 본 시험은 malathion이 방충제로 사용되었을 때 자연적인 곡물저장조건하에서의 잔류효력과 그의 지속성을 검정하기 위해서 1963년 6월부터 9월에 걸쳐 행하였다. 2) 백미를 malathion 유제로 처이하고 일령 21일된 쌀바구미를 일정기간마다 8일간 접종하여 살충율을 을 조사하고 이로서 malathion의 잔류효력과 지속성을 판정하였다. 3) 처리후 8일까지는 각 실험농도에서 $100\%$의 살충율을 나타내었고 32일에서 8ppm과 16ppm은 $100\%$의 살충율을 보였으나 4ppm과 2ppm에서는 각각 $85.8\pm3.70\%$와$ 43.3\pm10.77\%$의 살충율을 보였다. 32일 이후에서는 어느 농도에서나 $100\%$의 살충율은 볼 수 없었고 107일에 이르러서는 각 농도간 살충율에 차가 없었다. 4) 처리한 malathion의 반감기는 즉$50\%$의 살충율을 나타낸 것은 2ppm에서 33일, 4ppm에서 54일, 8ppm에서 73일. 16ppm에서 93일 이었다. 5) 자연곡물저장조건하에서 malathion 잔류효력을 5개월간 보지하려면 본 실험에서 사용한 농도보다 훨씬. 높여야 될 것으로 생각된다.

• 수산해양기술연구
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• 제53권1호
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• pp.60-66
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• 2017

This study researched the population of ecological characteristics of the goldeyes rockfish Sebasetes thompsoni sampled by gill net in the Ulleungdo area from February 2013 to February 2014 in order to assess the current stock status and provide scientific advice for management implementation. The instantaneous coefficient of total mortality (Z) was 0.78/year and the survival rate (S) was 0.459. The instantaneous coefficient of natural mortality (M) was 0.461/year. Based on the estimates of Z and M, the instantaneous coefficient of fishing mortality (F) was 0.318/year. The age at first capture ($t_c$) was 4.41/years. Current Yield-per-recruit (YPR) was 30.83 g, and fishing mortality at maximum YPR ($F_{max}$) and fishing mortality corresponding to 10% of the maximum slope in YPR curve ($F_{0.1}$) were 3.257/year and 0.673/year, respectively. $F_{35%}$ and $F_{40%}$, indicating fishing mortalities at 35% and 40% of maximum Spawning biomass-per-recruit (SBPR), were 0.619/year and 0.509/year, respectively. Based on the biological reference points, fishing mortality at overfished threshold yield ($F_{OTY}$) was calculated as 0.509/year. Current $SBPR/SBPR_{MSY}$ was 1.313 above 1.0, which means 'not overfishe,' while current $F/F_{OTY}$ was 0.629 below 1.0, which indicates 'not overfishing.' In conclusion, the current status of goldeyes rockfish was located in green zone (i.e., not overfished and not overfishing) according to the revised Kobe plot.

• 한국수산과학회지
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• 제54권3호
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• pp.293-297
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• 2021

Herein, two experiments were performed to determine the appropriate pH range and immersion time for organic acid-activating treatment (OAT) in a Pyropia farm. The effects of pH (0.50, 0.75, 1.00, 1.25, 1.50, 1.75, and 2.00) on the cell mortality of Pyropia yezoensis and Ulva linza thalli were tested after 20 sec of immersion under OAT. In addition, the cell mortality of the two species was estimated under various combinations of immersion time (30, 60, and 120 sec) and pH (1.00, 1.50, and 2.00). Upon 20 sec of immersion under OAT conditions, the cell mortality of P. yezoensis did not differ at any pH but that of U. linza exceeded 90% at a pH range of 0.50-1.00. P. yezoensis showed little cell mortality upon 30 sec of immersion, but its mortality exceeded 55% upon 120 sec of immersion at a pH range of 1.00-1.50. U. linza showed 67.9-100% mortality at a pH of 1.50 and 100% mortality at a pH of 1.00, regardless of the immersion time (30-120 sec). These results indicate that for the effective removal of U. linza, the optimal pH range is 1.00-1.50 and the optimal immersion time is 20-30 sec.

• Journal of the Korean Data and Information Science Society
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• 제28권2호
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• pp.271-286
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• 2017

본 논문은 우리나라 생명보험산업의 장수리스크에 대한 자연헤지가 충분히 이루어지고 있는가를 평가해 보았다. 연금보험과 종신보험 준비금 계산 시 사망률 모형으로는 Lee-Carter 모형을 적용하였다. 사망률 개선 시나리오로는 연금보험과 종신보험 사망률이 모두 10%와 20% 개선되는 경우, 50세 이하 저연령 사망률은 10% 개선되고, 50세 이상 고연령 사망률은 20% 개선되는 경우, 마지막으로 연금보험 사망률은 20% 개선되지만 종신보험 사망률은 10% 개선되는 등 네 가지 시나리오를 살펴보았다. 분석결과 연금보험과 종신보험에 동일한 사망률 충격을 가하는 경우와 고연령의 사망률 개선이 저연령에 비해 빠르게 나타나는 경우 모두 연금보험과 종신보험 준비금의 합은 감소하는 것으로 나타났다. 네 번째 시나리오에서만 전체 준비금은 증가하였으나, 이 경우에도 연금보험 준비금 증가의 60% 이상이 자연헤지에 의해 상쇄하는 것으로 나타났다. 따라서 우리나라 생명보험산업의 장수리스크는 자연헤지를 통해 충분히 관리되고 있다고 판단된다.

• 한국수산과학회지
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• 제35권4호
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• pp.380-385
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• 2002

본 연구에 사용되어진 마루자주새우 (Crangon hakodatei)는 거제도 주변 해역에서 2000년 10월부터 2001년 10월까지 새우조망을 이용하여 매월 채집하였다. 이들 개체군의 구조, 성장, 사망 및 성 성숙에 관한 분석은 갑각장을 이용한 체장빈도 데이터를 이용 ELEFAN 프로그램에 의해 분석하였다. 성장계수의 추정은 변형된 von Bertalanffy 성장식을 이용하였다. 암컷이 수컷보다 성장이 빨라 성숙개체에 빨리 도달하는 것으로 나타났다. 체장변환 어획 곡선에 의해 구해진 전 사망계수는 $3.10yr^{-1}$로 나타났고, Pauly 식에 의해 산출된 자연사망계수는 $2.48yr^{-1}$로 나타났다. 또한 어획사망계수는 $0.62yr^{-1}$인 것으로 나타났다. 암컷의 성 성숙 개체의 크기는 갑각장 $11.00\~11.50$ mm 사이인 것으로 나타났다.

• Journal of Korean Neurosurgical Society
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• 제29권3호
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• pp.330-335
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• 2000

Objective : The purpose of this report is to assess the morbidity and mortality associated with clipping of intracranial unruptured aneurysms. Methods : At the authors' institution between May 1989 and December 1998, a total of 128 unruptured aneurysms in 110 patients were treated with surgical clippings. The medical records and neuroimaging studies of the patients were reviewed retrospectively. Results : The main locations of the aneurysms were : middle cerebral artery 31%, internal carotid-posterior communicating artery 28%, anterior communicating artery 16%, paraclinoid 6.5%, internal carotid-anterior choroidal artery 7%, posterior circulation 7%. Forty three percent of the aneurysms were symptomatic and 57% asymptomatic. The overall outcome of the surgery was : Glasgow outcome scale(GOS) I 86%, GOS II 6%, GOS III 4.3%, GOS IV 0% and GOS V(death) 3.5%. The operative risk is higher for large to giant aneurysms, and for aneurysms in posterior circulations. Patients with non-giant aneurysm in anterior circulation showed no mortality, but morbidity of 8.2%, and in posterior circulation : 25% of mortality and 75% of morbidity. Patients with giant anterior circulation aneurysm have 22% of mortality and 22% of morbidity. For patients with giant posterior circulation aneurysm, mortality and morbidity were 25% and 25%, respectively. The postoperative deaths were related to occlusion of the major parent artery in 3 cases(75%). The postoperative morbidity was related to occlusion of artery(9/13), intraoperative rupture(3/13), and cranial nerve injury(1/13). Conclusion : This report documents 3.5% mortality and 13% of morbidity in the clipping surgery for unruptured intracranial aneurysms, and the relatively low risk of surgical clipping in non-giant and those located in anterior circulation. The natural history, especially risk of bleeding, of the unruptured intracranial aneurysms is still controversial. However, with respect to surgical results, unruptured non-giant aneurysm located in anterior circulation should be operated in patients with low risk.

• 대한예방의학회:학술대회논문집
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• 대한예방의학회 2000년도 제52차 추계학술대회 연제집
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• pp.221-222
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• 2000