선천성 심질환에서 방사선 영상 진단

김양민 한국소아심장연구회 2004 소아심장 Vol.8 No.1

Varying Nitrogen Fertigation for Cucumbers Grown in Greenhouses with Soil of Optimal or High Nutrient Status

김양민,이예진,송요성,이찬욱 한국토양비료학회 2022 한국토양비료학회지 Vol.55 No.1

The standard growth-stage-based fertigation schedule has provided the weekly supply amount of fertilizerconsidering the expecting yield with no regard of soil nutrient status. The study aimed to examine if fertigationwith nitrogen applied at a standard rate results in the best cucumber yield in two greenhouses with differentsoil nutrient levels, i.e. optimal and high. We investigated the nitrogen (N) uptake pattern of cucumbers withthe different nitrogen supply levels which included half the standard rate (N0.5), the standard rate (N1) anddouble the standard rate (N2). In year 2020, the N1 amendment resulted in highest yield in the soil withoptimal nutrient level, however, lower N0.5 resulted in higher yield in the high-nutrient soil. In year 2021,there was no statistical difference in the yield by different nitrogen supply levels in both soils with optimal andhigh nutrient level. Soil NO3-N remained low in the low nutrient soil regardless of the amount of N supplied,but soil NO3-N was high in the high nutrient soil supplied with N2. The Partial Factor Productivity of Nitrogen(PFPN) was highest in the N0.5 and it decreased as N supply increased in the optimal and high nutrient soil. Inconclusion, a precise fertigation schedule is needed to be set with the consideration of the soil nutrient status

When in Rome, Do as the Romans Do?:Similarities and Dissimilarities in the Forms and the Practices between Subsidiaries and Headquarters of Multinational Enterprises

김양민 한국전략경영학회 2006 전략경영연구 Vol.9 No.2

In the international business literature, classical studies posited a strong power asymmetry between the headquarters (HQs) and their subsidiaries, where the HQs are in charge of major decision making processes. A few recent studies in the field have suggested that subsidiaries also have much to say in the decision making process regarding the choice of the organizational forms and the practices in the host countries. Building on the strategic management perspectives and institutional theory, I develop a few propositions to explain the power relations between HQ and subsidiary, in deciding the extent to which MNEs’subsidiaries resemble local firms in the host country versus the extent to which they resemble the parent companies (i.e., HQ) in terms of their forms and practices. It is argued that strategic factors such as generic business level strategies and international corporate level strategies of the MNE, and institutional factors such as legal pressures, decide the levels of the similarities and dissimilarities in the forms and practices among the HQs, the subsidiaries of multinational corporations, and the local companies. 국제경영학 분야의 고전들을 고찰해 보면 다국적 기업의 본사와 지사 사이의 역학관계에 있어서 커다란 힘의 불균형- 즉 주로 본사가 전적으로 의사결정의 주도권을 갖고 지사는 철저하게 본사에 종속적인- 을 묘사한 연구가 많았음을 보게 된다. 그러나 최근의 몇몇 연구는 다국적 기업의 지사들도 조직의 형태나 현지시장에서의 행동에 관한 의사결정과정에서 큰 영향력을 행사한다는 주장을 펴고 있다. 본 논문은 전략이론과 제도화 이론을 기반으로, 과연 어떤 상황에서 다국적 기업의 지사가 그 사업행위나 조직 형태 면에서 본사와 유사해지는지, 또 어떤 상황에서 지사가 현지의 로컬기업과 그 행위나 조직 형태 면에서 유사해지는지에 대한 검증 가능한 제안들을 제시하였다. 본고는 전략적 변수들인 다국적기업 자신의 국제 기업전략, 즉 글로벌 전략이나 다국적 전략, 또는 본원적 전략, 즉 저 원가 또는 차별화 전략 등과, 제도적 요인인 현지의 상법 등이 다국적기업의 본사와 지사, 그리고 현지기업 사이의 차이점과 유사성을 결정짓는 주요 요인이라고 기술하였다.

Yield of Kimchi Cabbage and Soil Chemical Properties Following Slow Released Fertilizer Use in the Highlands of Gangwon

김양민,이정태,Mavis Badu Brempong,백계령 한국토양비료학회 2023 한국토양비료학회지 Vol.56 No.4

Fertilizer application is a major Kimchi cabbage production factor, which has been adopted historically to increase yields. However, conventional fertilizer (CF) use is associated with severe environmental concerns due to its nutrient release pattern and nutrient loss potential. Split applications of CF during the cultivation period also incurs extra labour costs. Slow release fertilizer (SRF),on the other hand, is applied one-time, hence it does not require extra labour, as it slowly releases nutrients over a span of time allowing nutrient release to synchronize with critical crop nutrient demand periods. It has been suggested as an alternative to CF to curb the environmental menace. In our study, we compared the effect of CF and SRF on soil nitrogen (N) dynamics, Kimchi cabbage yield and residual soil chemical properties in the growing seasons of 2021 and 2022 at the Highland Agriculture Research Institute in the Gangwon State Government, under rain-fed conditions. The CF resulted in high soil NH4 + and NO3 - concentrations during the last period of cultivation, however, SRF showed a slow increase pattern of the nutrients up to the middle of the cultivation period and then a decrease till the harvest time. Kimchi cabbage yields were similar under CF and SRF in 2021 (43 and 48 Mg ha-1 respectively) and 2022 (81 and 79 Mg ha-1 respectively). The CF left the highest residual soil NH4 + and NO3 - concentrations in 2021 (12 and 24 mg kg-1) and 2022 (24 and 22 mg kg-1). Considering that similar yields were affected by CF and SRF, it could be inferred that more soil N from CF were subject to losses and potential environmental concerns, as CF affected higher soil N concentrations during the growing seasons and after harvest. Holding all other crop production factors constant, SRF has an advantage over CF in terms of saving labour costs and potentially protecting the environment.

허혈성 심질환의 자기공명영상

김양민,Kim, Yang-Min 대한영상의학회 2004 대한영상의학회지 Vol.50 No.2

MRI has achieved many technical advances in the spatial resolution, temporal resolution, contrast resolution, signal-to-noise ratio, and postprocessing technique. At one session of examination within a tolerable time, MRI can provide integrated information on coronary artery stenosis, systolic dysfunction, myocardial perfusion, and myocardial viability. Delayed enhancement study after contrast administration is highly reproducible and offers unique vision for myocardial viability in the patients with myocardial infarction. Cardiac MRI is very cost-effective and may be one-stop solution for the evaluation of ischemic heart disease.

대동맥궁 기형 환자에서 나선형 CT를 이용한 3차원 영상 진단의 유용성

김양민,김태훈,김미영 世宗醫學硏究所 2000 世宗醫學 Vol.17 No.2

Evaluating Soil Loss in a Kimchi Cabbage Cropping System in the Highlands of Gangwon, Korea

김양민,이정태,Mavis Badu Brempong,백계령 한국토양비료학회 2023 한국토양비료학회지 Vol.56 No.4

Evaluating Soil Loss in a Kimchi Cabbage Cropping System in the Highlands of Gangwon, Korea

혈관모형을 이용한 CT 혈관조영 영상의 질에 영향을 미치는 해부학적, 촬영 및 재구성 변수에 대한 연구

김양민,정진욱,김태훈,김미영,조준희,차상훈,Kim, Yang-Min,Jeong, Jin-Uk,Kim, Tae-Hun,Kim, Mi-Yeong,Jo, Jun-Hui,Cha, Sang-Hun 대한영상의학회 2002 대한영상의학회지 Vol.47 No.1

Purpose: To investigate the image quality of CT angiograms obtained with various anatomical, scanning, and reconstruction parameters using a phantom with small vessels, and to determine the technique appropriate to a specific vascular anatomy. Materials and Methods: The vascular phantom consisted of three pairs of parallel tubes with a luminal size of 1, 2, and 3 mm. Using the phantom, CT scans were obtained at three inter-tubal distances (1, 2, and 3 mm), three angles of inclination relative to the z-axis (0 degree, 45 degree, and 90 degree), three collimation widths (1, 3, and 5 mm) and two pitch factors (1 and 2). Using axial images obtained at 1-, 2-, and 3-mm reconstruction intervals, two types of three-dimensional images were rendered, and the quality of 972 such images was subjectively graded in terms of edge definition and artifact by three radiologists. Results: All vessels parallel to the z-axis showed good image quality irrespective of other factors. A pair of vessels separated by 1 mm appeared to be stuck to each other. As collimation width and reconstruction interval increased, image quality decreased significantly and artifact increased. The quality of images obtained at 3 mm collimation and with a 6 mm increment was significantly better where collimation and increment were both 5 mm (p=0.001). Vessels 1 mm in size suffered artifactual degradation, especially in the case of SSD images. Most obliquely oriented vessels showed stair-step artifact, which tended to be severe when the reconstruction interval was large. Conclusion: In small vessels perpendicular to or inclined relative to the z-axis, a smaller collimation width and reconstruction interval lessens image degradation. When wider scan coverage is intended, a larger pitch rather than a larger collimation width is recommended. To lessen the artifacts occurring where vessels are obliquely oriented, the reconstruction interval should be reduced. 목적: 혈관모형을 이용하여 혈관의 해부학적인 양상, 스캔 변수나 삼차원 영상 재구성 방법이 CT 혈관조영 영상의 질에 미치는 영향을 분석하여, 혈관의 해부학적인 양상에 따른 적절한 검사방법을 찾고자 하였다. 대상과 방법: 내경이 1,2,3 mm인 도관 두 개씩을 평행하게 배열하고 쌍이 되는 두 도관의 거리가 조절되는 혈관 모형을 제작하였다. 두 도관사이의 거리를 1,2,3 mm로 조절해서 이를z-축과 평행(z=0 $^{\circ}$),경사(z=45 $^{\circ}$),그리고 직각(z=90 $^{\circ}$)으로 놓고, 절단두께 1,3,5 mm와 피치 1,2를 조합하여 스캔을 하였다.1,2,3 mm재구성간격으로 얻어진 횡단면 영상으로 만든972개의 삼차원 영상의 질을 세 명의 방사선과의사가 주관적으로 점수화하여 평가하였다. 결과: 도관이 z-축에 평행인 경우에는 다른 요소들에 상관없이 영상의 질이 모두 좋았다. 1mm 간격의 두 도관은 어떤 방법으로도 구분이 안 되었다. 절단두께, 재구성간격의 증가에 따라서 영상의 질이 유의하게 나빠졌다. 절단두께/테이블 이동속도가 3 mm/6 mm로 얻은 영상이 5 mm/5 mm인 영상보다 우수하였다.1 mm내경의 도관은 특히 SSD 영상에서 가성 협착이 생겼다. z-축과 비스듬하게 배열된 도관은 계단 모양 인공물이 나타났는데 재구성간격이 큰 경우에 심했다. 결론:z-축과 비스듬히 또는 수직으로 배열된 혈관의 영상을 좋게 하려면 작은 절단두께와 재구성간격을 사용한다. 스캔의 범위를 넓히려면 절단두께보다는 피치를 높이는 것이 좋다. 비스듬한 방향의 혈관에서 보이는 계단모양 인공물을 줄이려면 재구성간격을 줄여야 한다.

MRI를 이용한 허혈성 심질환의 One-spop 진단

김양민 대한의사협회 2003 대한의사협회지 Vol.46 No.11

Buerger씨 병에 있어서 Prostaglandin EL 동맥 주입을 통한 치험 3례보고

김양민 대한영상의학회 1990 대한영상의학회지 Vol.26 No.4

In Buerger's disease, arterial occlusion is so peripheral that reopening procedure such as recontructive vascular surgery, percutaneous transluminal angioplasty and local fibrinolysis are not feasible, and major amputation is the only alternative. Prostaglandin El, a potent vasodilator and inhibitor of platelet aggregation, has been used to treat the patients with severe arterial occlusive disease. In three cases of Buerger's disease. who were manifested by resting pain, non-healing ischemic ulcer, or impending gangrene and who were not candidates for direct arterial reconstructive procedure, we infused Prostaglandin El intra-arterially at a fixed dosage to evaluate its effectviveness. We report our experience with the use of this drug in relieving the ischemic symptoms, healing the intractable ulcer, or avoiding the major amputation.