林土의 有機物의 分解速度와 無機養料의 垂直分布에 關한 考察

金遵敏,張楠基,鄭玩鎬 서울대학교 교육대학원 학술연구회 1966 論文集 - 서울대학교 교육대학원 Vol.3 No.-

Kim Choon Min, Chang Nam Kee and Chung Whan Ho: Decomposition rate of plant residue and the vertical distibution of mineral nutrients in the woodland soil. The relationship between decomposition rate of litter and the amount of mineral nutrients dispersed to the soil horizons were studied on the oak and pine forest stand. The results are as follows: 1. Decomposition rate of litter was highest in the F horizon of the oak stand, however in the pine stand it was highest in H horizon. 2. The correlation coefficients between decomposition rate and humus, organic carbon, moisture content, calcium, phosphorus, and nitrogen in the pine stand are; 0.90, 0.98, 0.76, 0.98, and 0.88, in oak stand; 0.97, 0.93, 0.92, 0.97, 0.74 and 0.73. 3. Factors which affect the decomposition rate of litter are humus, organic carbon, moisture content, calcium, phosphorus and nitrogen. 4. Among the variables, PH, moisture content and phosphorus under the oak and pine forest showed significant differences in each horizon. 5. C/N ratio of pine stands is higher than that of oak stands studied. 6. The vertical distribution of mineral nutrients is highly related with the amount of humus accumulated on top soil.

디지털 경제시대에서의 중소기업 인적자원 개발

김환식 한국직업능력개발원 2001 직업능력개발연구 Vol.4 No.2

In general, the 21C is called the knowledge-based society, which is strengthened by digital economy, characterized as ICT industry, Internet, e-commerce and so on. According to the advent of the digital economy age, SMBs has come to compete with the large enterprises equally. That's because the size, distance and space are not the factor of competitiveness power furthermore. If SMBs have gotten the new and state-of-the-art technology and made strong efforts to innovate, they are capable of competing and sometimes held a prominent position. However, the technology and innovation will be able to realize by human resources. After all, the competitiveness of SMBs will be determined by the recruiting and managing of the competent human resources. The supporting system of the HRD of workers in SMBs is represented as vocational competency development program based on the vocational training promotion act. Usually, the HRD of workers in SMBs is a field of market failure, because of externalities of HRD. To relieve market failure and build up skill development of SMBs workers, the HRD for SMBs workers is treated preferentially as compared with the HRD for SMBs workers under the provision fo the act. However, the actual results were not produced differently to the intention. This is possible not only because of market failure, but also because of government failure. So the program and system have to be renovated and reformed. The direction of HRD for SMBs workers, especially at from the side of governmental supporting system and program, is as follows. The approaches and methods suggested in the paper are not coherent. First, the HRD supporting system for SMBs worker is reviewed and the distinguished regulation between SMBs and large companies is also reviewed whether it is rationalized the digital economy age or not. Second, government (government funded institution) has to help SMBs to make a plan on HRD based on business strategy financially. The employment insurance act has to be revised. Vocational competency development program has to be renovated into fitting social insurances purpose, if the program is linked with the employment insurance continuously. In addition, the program, related to HRD for SMBs workers, working in ministry of education and human resources development and small and medium business administration are also connected with vocational competency development. The national HRD strategies for SMBs workers have to be discussed and established at the ministerial counciil for HRD.

Phenol Novolac 수지 경화제의 연화점 변화에 따른 Epoxy Molding Compound의 물성 변화

김환건 서경대학교 1995 論文集 Vol.23 No.2

반도체를 보호하기 위하여 사용하는 반도체 성형 재료로, 현재 주로 사용되고 있는 Epoxy Molding Compound(EMC)에 경화제로 사용되고 있는 phenol novolac의 특성과 성형 재료의 관계를 조사하기 위하여 phenol novolac resin의 분자량과 깊은 관련이 있는 수지의 연화점 변화에 따른 EMC의 물성 변화를 살펴보았다. 사용된 phenol novolac 수지의 연화점은 각각 83℃, 88℃, 99℃인 3종을 사용하였으며 연화점 변화에 따른 EMC의 물성 변화를 살펴보기 위하여 기계적 물성 특성으로 굽힘 강도와 굽힘 탄성율을, 열적 특성 변화를 관찰하기 위하여 열팽창 계수와 열전도도 그리고 유리 전이온도를 각각 측정하였다. 그리고 성형 특성과의 관계를 살펴보기 위하여 spiral flow를 측정하였고, 전기적 특성으로서 volume resistivity를 측정 비교하였다. 기계적 물성측면에서 보면 탄성율은 연화점이 88℃에서 최소값을 보였으며, 강도는 88℃에서 가장 높은 결과를 나타내었다. 열적특성부문에서 살펴보면 유리 전이온도 이하 영역의 열팽창 계수(a_1)와 유리 전이온도 이상 영역의 열팽창 계수(a_2) 모두 연화점 변화에 따라 큰 변화를 보여주지 못하였다. 또한 유리 전이온도는 연화점 증가에 따라 감소하는 경향을 나타내었으나, 열전도도는 연화점 변화에 따라 변화를 보여주지 못하였다. 성형 특성 측면에서는 관계를 살펴보면 연화점이 88℃인 수지의 경우 spiral flow 가 최대치를 보이며 연화점이 증가함에 따라 더 이상 증가하지 않았다. 이러한 물성으로부터 내부응력을 계산하여 성형물의 특성을 고찰하였다. The physical properties of epoxy molding compound(EMC) according to the change of softening point of phenol novolac resin as hardener have been investigated in order to study the relationship between the properties of phenol novolac resin, which is main hardener of EMC for semiconductor encapsulation, and EMC. The softening points of used phenol novolac resin are 83℃, 88℃, and 99℃, respectively. The flexural strength and flexural modulus as mechanical properties were measured, and thermal expansion coefficient, thermal conductivity and temperature of glass transition(Tg) as thermal properties, spiral flow as moldability, and volume resistivity as electrical properties have been investigated to see the change of physical properties of EMC. The minimum of flexural modulus of EMC was represented at 88℃, and the maximum of flexural strength was done at 88℃. The thermal expansion coefficients in the region below Tg(a_1) and above Tg(a_2) keep constant value according to the change of softening point. Tg decreases with the increase of softening point of phenol novolac resin, but thermal conductivity is not hardly changed with that. It can be found out that spiral flow of EMC does not increases any longer above 88℃. We have considered these system in respect of internal stress.

Site-directed Mutagenesis에 의한 RBP(Ribose Binding Protein)의 #5-Ala의 치환과 rbsB103 복귀 돌연변이의 분리

정환웅,백광희 경희대학교 유전공학연구소 1995 遺傳工學論文集 Vol.7 No.-

Ribose-binding protein (RBP) of E coli function in the periplasm as a component of a high affinity transport system for ribose and as a primary receptor for chemotaxis toward ribose. A mutant (rbsB103) in the signal sequence of RBP has a defect in the export of the protein to the periplasm. The intragenic suppressors for rbsB103 were isolated genetically. One of them had a change at 5th amino acid of RBP. In order to assess the role of the 5th amino acid in the transport of rbsB103, we substituted the alanine of 5th position with various amino acids by site-directed mutagenesis. The mutants replaced by Arg, Asp, Pro, or Ser at 5th amino acid of RBP can suppress the defect of protein transport.

B+트리를 위한 벌크로드

황환규,김상욱 江原大學校 産業技術硏究所 1995 産業技術硏究 Vol.15 No.-

In this paper, we propose a bulk-load algorithm for B' -trees, the most widely used index structures in database systems. The main characteristic of our algorithm is to simultaneously process all the keys to be placed on each B' -tree page when accessing the page. This avoids the overhead for accessing the same page multiple times, which results from applying the B' -tree insertion algorithm repeatedly. For performance evaluation, we analyze our algorithm in terms of the number of disk accesses. The results show that the number of disk accesses excluding those in the redistribution process in identical to the number of B' -tree pages. Considering that the redistribution process is an unavoidable preprocessing step for bulk-loading, our algorithm requires just one disk access per B' -tree page, and therefore turns out to be optimal. We also present performance tendancy according to the changes of parameter values via simulation.

급성 바이러스간염의 간침생검조직소견

정환국 대한의학협회 1973 대한의학협회지 Vol.16 No.12

동적 선택률 추정 기법을 위한 오차 분석

황환규,김상욱 강원대학교 정보통신연구소 1997 정보통신논문지 Vol.1 No.-

In this paper, we analyze the errors occurred in a selectivity estimation method based on dynamic maintenance of data distribution, which employs the mulitilevel grid file(MLGF), a multidimensional file structure. We first demonstrate that the estimation errors stem from the uniformity assumption that records are uniformly distributed in their belonging region represented by an entry in a level of an MLGF directory. Based on this demonstration, we then investigate five factors affecting the accuracy of estimation: (1) the data distribution in a region, (2) the number of records stored in an MLGF, (3) the page size, (4) the query region size, and (5) the level of an MLGF directory. Next, we present the tendency of estimation errors according to the change of values for each factor through experiments. The results show that the errors decrease when (1) the distribution of records in a region becomes closer to the uniform one, (2) the number of records in an MLGF increases, (3) the page size decreases, (4) the query region size increases, and (5) the level of an MLGF directory employed as data distribution information becomes lower.

大邱達城公園 入場客의 行態

李奐基 啓明大學校 産業經營硏究所 1980 經營經濟 Vol.12 No.1

The pourpose of this study is to present the various data for better establishment of tourism geographical policy as well as to contribute to the improvement of park-planning, landscape gradening, and facilities and management of parks in implementing the urban park project. To analyze and identify the behavior pattern of the visitors of Dalseong Park,, the actual research on the characteristics and the distributions of the tourists has been emphasized. The details of the actual research on the visitors of Dalseong Park is as follows: 1) Research period: 14-20 May, 1979(one week-since the number of the visitors in the time marked the highest in the year) 2) Research method: personal interviews and written questionaires. 3) Selection of sujects: Rendom sampling method. 4) Number of respondents: 558 persons. In order to prove the process of changes and regional distributions of the visitors: some data and additional informations provided by the Office of Dalseong Park and the Park Division of Daegu City have been utilized in drawing the diagrams and maps. The summary of the examination on the behavior pattern of the visitors is as follows: 1) 73.3% of the total visitors are youth -most of the males are in twenties while the females are in teens. By measures above citioens, young or old, man or woman would be able to rest and eojoy their leisure time in the pleasant surrouodings and would make a park an urban-resource to play a part of a??tracting sight-seers to Daegu.

전기충격요법 사용에 관한 정신과의사의 견해 및 실시현황

정환증,변원탄 大韓神經精神醫學會 1983 신경정신의학 Vol.22 No.4

한국 정신과 의사 211명의 전기충격요법에 관한 의견을 다음과 같이 요약할 수 있었다. 1. 735가 치료방법으로서의 전기충격요법을 찬성하는 태도였고, 찬성하는 가장 큰 이유로서는 적응증만 잘 고려된다면 일반적으로 우수한 효과를 볼 수 있다는 것이었다. 그러나, 그 실제적인 사용에 있어서는 다수에서 조심스러운 태도를 보이고 있었고, 어떤 견해에 있어서는 미국의 정신과 의사들보다 훨씬 더 소극적인 태도를 가지고 있었다. 2. 전기충격요법의 적응증에 관한 한 역시 예상한 바와 같이 주요 우울장애, 조증 흥분, 정신분열증의 순으로 찬성하는 경향이 많았고, 이 방법을 선택한 이유로는 '응급처치로 시행하거나' 다른 치료방법에 실패했거나' '보다나은 결과를 얻기 위한 병용 치료로서 선택' 등이 가장 많았다. 3. 정신분열증에서의 전기충격요법은 사용의 한계를 나타내고 있었다. 4. 시행 이전의 동의나 시행 전 감사에 대해서는 비교적 엄격한 태도를 유지하고 있으나, 연성 전기충격요법, 편측 전기충격요법의 활용은 적었으며, 강력 또는 유지 전기충격요법 역시 시행율이 낮은 편이였다. 시행빈도는 79%가 주2-3회를 실시하는 것으로 나타났고, 향정신약물을 사용하던 환자에서 전기충격요법을 시행한 경우, 대체로 약간의 약물 감량을 실시하는 것으로 나타났다(59%) 5. 전기충격요법 시행 이후의 합병증으로는 골절이나 탈구, 직업 수행 능력에 영구적인 장애, 자발적인 경련 발작 등이 예상외로 많아 합병증은 역시 소홀히 할 수 없는 문제임을 나타내 보였으며, 전기충격요법 이후 24시간이내 사망을 경험한 예가 6경우가 있었다. The authors of this suveyed the opinions of 211 Korean psychiatrists about the use of Electoconvulsive Theraoy(ECT). The results of the survey are summarized as follows; 1. ECT was accepted with a favorable attitude by 73% of the psychiatrists surveyed. The most common reason for agreement was that if indication is followed the ECT generally produces excellent results. But in actual clinical practice most Korean psychiatrists are hesitant in preforming the ECT and have a somewhat less active attitude towards ECT than psychia trists in America. 2. The major indications for theuse of ECT were major depression, manic excithment and schizophrenia in the order of their frequency. The main reasons for the selection of ECT as a therapeutic tool were emergency therapy, when all other treatment methods have failed and as a combined treatment that can. 3. The use of the ECT for the treatment of schizophrenia was very limited for a few selected cases. 4. Korean psychiatrists showed relatively rigid adherence to obtaining the consent before ECT and the preoperational work-up. The softening and unilateral ECT had received little use in Korea and a similar tendency was shown towards intensive and maintenance ECT. Most psychiatrists(79%) tended to use the ECT 2 or 3 times a ewek with a majority of their patients. In cases where the ECT was used in concomitant with antipsychotic drug therapy, there showed a tendency for a slight reduction in drug dosages during the ECT. 5. Post-ECT complications and/or adverse effects were fracture, dislocation, premanent disability in occupational performane and spontaneous seizures etc. Occurrences of above complications seem to be mlre than expected in this study and this was not negligible. A total of six patients were known to habe expired within twenty-four hours after ECT.

비감염성 설사

정환국,유재영 대한감염학회 1978 감염 Vol.10 No.1