• Title/Summary/Keyword: IV method

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Time-Varying Effects of Oil Shocks on the Korean Economy (한국경제에 미치는 유가충격의 시간-가변적 효과에 관한 연구)

  • Cha, Kyungsoo
    • Environmental and Resource Economics Review
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    • v.27 no.3
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    • pp.495-520
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    • 2018
  • Because of structural changes in the international oil market and the economy, it is widely recognized that the impact of oil shocks on the economy has weaken since the mid-1980s. This study tries to examine the validity of the recent perception about the relationship between oils shocks and the economy, estimating the time-varying effects of oil shocks on the Korean economy. The results show that the dynamic effects of oil shocks normalized to a one standard deviation has been relatively constant, in contrast to the recent perception and a number of existing studies. In addition, because the shape of impulse response functions at each point in time spanning from 1984:II to 2017:IV has not been changed significantly, it seems that the propagation mechanism of oil shocks also has not been substantially altered. These findings indicate that even though structural changes of the economy, such as the reduction in the share of oil consumption and the spread of high-efficiency energy technologies, have been rapidly progressed, it is not still enough to offset the negative effects of oil shocks. Rather, it seems that the recent perception about the shrinking effects of oil shocks is mainly due to the assumptions that do not reflect changes in the size of oil shocks. In particular, this problem appears more pronounced in the case of the typical a one standard deviation increase oil shock under homoskedasticity assumption, which is widely adopted in the most VAR analyses. Therefore, in estimating the effects of oil shocks on the economy, it is important to specify the correct model and normalization method, to reflect changes in the size of oil shocks.

Compensation of Surface Temperature Effect in Determination of Sugar Content of Shingo Pears using NIR (근적외선을 이용한 신고 배 당도판정에 있어 표면 온도영향의 보정)

  • 이강진;최규홍;김기영;최동수
    • Journal of Biosystems Engineering
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    • v.27 no.2
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    • pp.117-124
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    • 2002
  • This research was conducted to develop a method to remove the effect of surface temperature of Shingo pears for sugar content measurement. Sugar content was measured by a near-infrared spectrum analysis technique. Reflected spectrum and sugar content of a pear were used for developing regression models. For the model development, reflected spectrums having wavelengths in the range of 654 to 1,052nm were used. To remove the effect of surface temperature, special sample preparation techniques and partial least square (PLS) regression models were proposed and tested. 71 Shingo pears stored in a cold storage, which had 2$^{\circ}C$ inside temperature, were taken out and left in a room temperature for a while. Temperature and reflected spectrum of each pear was measured. To increase the temperature distribution of samples, temperature and reflected spectrum of each pear was measured four times with one hour twenty minutes interval. During the experiment, temperature of pears increased up to 17 $^{\circ}C$. The total number of measured spectrum was 284. Three groups of spectrum data were formed according to temperature distribution. First group had surface temperature of 14$^{\circ}C$ and total number of 51. Second group consisted of the first and the fourth experiment data which contained the minimum and the maximum temperatures. Third group consisted of 155 data with normal temperature-distribution. The rest data set were used for model evaluation. Results shelved that PLS model I, which was developed by using the first data group, was inadequate for measuring sugar content of pears which had different surface temperatures from 14$^{\circ}C$. After temperature compensation, sugar content predictions became close to the measured values. Since using many data which had wide range of surface temperatures, PLS model II and III were able to predict sugar content of pears without additional temperature compensation. PLS model IV, which included the surface temperatures as an independent variable. showed slightly improved performance(R$^2$=0.73). Performance of the model could be enhanced by using samples with more wide range of temperatures and sugar contents.

Treatment of Stomach Cancer Involving Esophagogastric Junction (식도-위 경계부위를 침범한 위암의 치료)

  • 이종목;백희종;박종호;임수빈;조재일
    • Journal of Chest Surgery
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    • v.34 no.12
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    • pp.930-936
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    • 2001
  • Background: The origin site of carcinoma invading esophagogastric junction is variable. It may arise from squamous cell carcinoma of low esophagus, adenocarcinoma arising from Barrett's esophagus, adenocarcinoma of gastric cardia, or extension from proximal stomach cancer. In Korea, the majority of adenocarcinoma invading esophago-gastric junction seems to arise from proximal gastric carcinoma. Material and Method: We reviewed the data of surgically-resected gastric adenocarcinoma involving esophagogastric junction in KCCH between 1988 and 1999. Result: There were 212 cases. Male to female ratio was 156 to 56. Age distribution was between 22 and 78. Variable surgical approaches including median laparotomy, laparotomy with left or right thoracotomy, left thoracotomy, and thoracoabdominal approach were used. Postoperative pathologic stages were : Stage IA-7, IB-11, Ⅱ-25, ⅢA-73, ⅢB-34, and Ⅳ-57. Curative resection was performed in 199 patients, and total gastrectomy was performed in 200 patients. There were 77.4%(164 cases) with esophageal involvement, 74.1%(157 cases) with tumor involvement in the abdominal LN, and 8%(17 cases) with mediastinal LN metastasis. Operative mortality was 3.3%, and over-all 5 year survival rate was 35%. Conclusion: There are various surgical approaches and many things to consider for surgical resection, thoracic and abdominal approach may need for obtain proper resection margin and adequate lymph node dissection in stomach cancer invading esophagogastric junction.

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Fabrication of Photocatalyst Glass Beads Coated with TiO2 Thin Film by a Layer-by-Layer Process (LBL법에 의해 TiO2막이 코팅된 광촉매 글라스 비드 제조)

  • Lee, Ji-Sun;Chae, Yoo-Jin;Lee, Mi-Jai;Kim, Sei-Ki;Hwang, Jong-Hee;Lim, Tae-Young;Hyun, Soong-Keun;Kim, Jin-Ho
    • Korean Journal of Materials Research
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    • v.22 no.7
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    • pp.379-383
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    • 2012
  • $TiO_2$ thin films consisting of positively charged poly(diallyldimethylammonium chloride)(PDDA) and negatively charged titanium(IV) bis(ammonium lactato) dihydroxide(TALH) were successfully fabricated on glass beads by a layer-by-layer(LBL) self-assembly method. The glass beads used here showed a positive charge in an acid range and negative charge in an alkaline range. The glass beads coated with the coating sequence of(PDDA/TALH)n showed a change in the surface morphology as a function of the number of bilayers. When the number of bilayers(n) of the(PDDA/TALH) thin film was 20, Ti element was observed on the surface of the coated glass beads. The thin films coated onto the glass beads had a main peak of the (101) crystal face and were highly crystallized with XRD diffraction peaks of anatase-type $TiO_2$ according to an XRD analysis. In addition, the $TiO_2$ thin films showed photocatalytic properties such that they could decompose a methyl orange solution under illumination with UV light. As the number of bilayers of the(PDDA/TALH) thin film increased, the photocatalytic property of the $TiO_2$-coated glass beads increased with the increase in the thin film thickness. The surface morphologies and optical properties of glass beads coated with $TiO_2$ thin films with different coating numbers were measured by field emission scanning electron microscopy(FE-SEM), X-ray diffraction(XRD) and by UV-Vis spectrophotometry(UV-vis).

A Basic Study for Development of Clinical Practice Guidelines of Korean Medicine in Autism Spectrum Disorder -Based on Pre-existing Clinical Practice Guidelines of Autism Specturm Disorder- (자폐스펙트럼장애의 치료에 대한 한의 임상 가이드라인 개발을 위한 기초연구 -기존에 개발된 자폐스펙트럼장애 가이드라인을 중심으로-)

  • Kim, Sang Min;Lee, Jin Yong;Lee, Sun Haeng;Chang, Gyu Tae
    • The Journal of Pediatrics of Korean Medicine
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    • v.31 no.1
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    • pp.52-62
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    • 2017
  • Objectives The purpose of this study is to review pre-existing clinical practice guidelines for autism spectrum disorders, and refer those in developing a new practice guideline. Methods A total of 9 existing clinical practice guidelines for autism spectrum disorder developed from 2010 to 2016 were searched by Google scholar and Pubmed, and were reviewed those literatures in three parts: general, diagnosis & evaluation, and intervention. Results There were no consistency in the recommendation methods of 9 clinical care guidelines (such as the method of rating and recommendation intensity for diagnosis, evaluation, and treatment). However, in the diagnosis and evaluation section, frequently used evaluation and diagnostic tools are mentioned in most clinical practice guidelines, and the types of pharmacologic and non-pharmacological treatments that are mainly recommended in treatment are equally mentioned in most clinical practice guidelines could confirm. Conclusions 1. Some guideline recommendations are graded according to each criterion. Recommendations presented in various databases were based on systematic reviews or other literatures. The most utilized database were PsycINFO, CINAHL, Cochrane. 2. DSM-5 and ICD-10 were the most common used diagnostic criteria, and DSM-IV was used as a diagnostic standard in the guideline published before 2013. The tools used for diagnosis and evaluation were also varied. However, most recommended ones were ADI-R, ADOS-G, and DISCO. 3. Treatment was largely divided into pharmacological intervention and non-pharmacological intervention. In some guideline, the interventions were divided into pediatric and adult. Most of the pharmacological interventions were not recommended due to lack of evidence, but in cases in which specific symptoms were aimed, they recommended to seek professional help. 4. In addition to interventions, each guideline referred to supportive interventions that may be helpful in the daily life of patients with ASD, which may need to be addressed in future clinical guidelines.

Estimation of Carbon Stock by Development of Stem Taper Equation and Carbon Emission Factors for Quercus serrata (수간곡선식 개발과 국가탄소배출계수를 이용한 졸참나무의 탄소저장량 추정)

  • Kang, Jin-Taek;Son, Yeong-Mo;Jeon, Ju-Hyeon;Yoo, Byung-Oh
    • Journal of Climate Change Research
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    • v.6 no.4
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    • pp.357-366
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    • 2015
  • This study was conducted to estimate carbon stocks of Quercus serrata with drawing volume of trees in each tree height and DBH applying the suitable stem taper equation and tree specific carbon emission factors, using collected growth data from all over the country. Information on distribution area, tree number per hectare, tree volume and volume stocks were obtained from the $5^{th}$ National Forest Inventory (2006~2010), and method provided in IPCC GPG was applied to estimate carbon storage and removals. Performance in predicting stem diameter at a specific point along a stem in Quercus serrata by applying Kozak's model,$d=a_1DBH^{a_2}a_3^{DBH}X^{b_1Z^2+b_2ln(Z+0.001)+b_3{\sqrt{Z}}+b_4e^Z+b_5({\frac{DBH}{H}})}$, which is well known equation in stem taper estimation, was evaluated with validations statistics, Fitness Index, Bias and Standard Error of Bias. Consequently, Kozak's model turned out to be suitable in all validations statistics. Stem volume tables of Quercus serrata were derived by applying Kozak's model and carbon stock tables in each tree height and DBH were developed with country-specific carbon emission factors ($WD=0.65t/m^3$, BEF=1.55, R=0.43) of Quercus serrata. As a result of carbon stock analysis by age class in Quercus serrata, carbon stocks of IV age class (11,358 ha, 36.5%) and V age class (10,432; 33.5%) which take up the largest area in distribution of age class were 957,000 tC and 1,312,000 tC. Total carbon stocks of Quercus serrata were 3,191,000 tC which is 3% compared with total percentage of broad-leaved forest and carbon sequestration per hectare(ha) was 3.8 tC/ha/yr, $13.9tCO_2/ha/yr$, respectively.

Analysis of Genetic Relationship of Pear (Pyrus spp.) Germplasms Using AFLP Markers (AFLP 표지를 이용한 배 유전자원의 유연관계 분석)

  • Cho, Kang-Hee;Shin, Il Sheob;Kim, Hyun Ran;Kim, Jeong-Hee;Heo, Seong;Yoo, Ki Yeol
    • Korean Journal of Breeding Science
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    • v.41 no.4
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    • pp.444-450
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    • 2009
  • Amplified fragment length polymorphism (AFLP) marker was utilized for evaluation of genetic diversity of 60 pear germplasms. Twenty selective AFLP primer pairs generated a total of 522 polymorphic amplification products. From UPGMA (unweighted pair-group method arithmetic average) cluster analysis by using polymorphic bands, the pear germplasms were divided into four clusters by similarity index of 0.691. The first cluster (I) included European pears belonging to Pyrus communis and wild species such as P. nivalis and P. cordata. The second cluster (II) included Ussurian pea pears belonging to P. betulaefolia and P. fauriei. The third cluster (III) included pea pears belonging to P. calleryana and P. koehnei. Most of germplasms belonging to P. pyrifolia and P. ussuriensis, and interspecific hybrids were included in the fourth (IV) cluster. Therefore pear germplasms originated from East Asia were closely related to P. pyrifolia and P. ussuriensis. Similarity values among the tested pear germplasms ranged from 0.584 to 0.879, and the average similarity value was 0.686.

Protein molecular structure, degradation and availability of canola, rapeseed and soybean meals in dairy cattle diets

  • Tian, Yujia;Zhang, Xuewei;Huang, Rongcai;Yu, Peiqiang
    • Asian-Australasian Journal of Animal Sciences
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    • v.32 no.9
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    • pp.1381-1388
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    • 2019
  • Objective: The aims of this study were to reveal the magnitude of the differences in protein structures at a cellular level as well as protein utilization and availability among soybean meal (SBM), canola meal (CM), and rapeseed meal (RSM) as feedstocks in China. Methods: Experiments were designed to compare the three different types of feedstocks in terms of: i) protein chemical profiles; ii) protein fractions partitioned according to Cornell Net Carbohydrate and Protein System; iii) protein molecular structures and protein second structures; iv) special protein compounds-amino acid (AA); v) total digestible protein and energy values; vi) in situ rumen protein degradability and intestinal digestibility. The protein second structures were measured using FT/IR molecular spectroscopy technique. A summary chemical approach in National Research Council (NRC) model was applied to analyze truly digestible protein. Results: The results showed significant differences in both protein nutritional profiles and protein structure parameters in terms of ${\alpha}-helix$, ${\beta}-sheet$ spectral intensity and their ratio, and amide I, amide II spectral intensity and their ratio among SBM, CM, and RSM. SBM had higher crude protein (CP) and AA content than CM and RSM. For dry matter (DM), SBM, and CM had a higher DM content compared with RSM (p<0.05), whereas no statistical significance was found between SBM and CM (p = 0.28). Effective degradability of CP and DM did not demonstrate significant differences among the three groups (p>0.05). Intestinal digestibility of rumen undegradable protein measured by three-step in vitro method showed that there was significant difference (p = 0.05) among SBM, CM, and RSM, which SBM was the highest and RSM was the lowest with CM in between. NRC modeling results showed that digestible CP content in SBM was significantly higher than that of CM and RSM (p<0.05). Conclusion: This study suggested that SBM and CM contained similar protein value and availability for dairy cattle, while RSM had the lowest protein quality and utilization.

Prediction of the Optimal Growth Site and Estimation of Carbon Stocks for Quercus acuta in Wando Area (완도지역의 붉가시나무 생육 적지예측 및 탄소저장량 추정)

  • Hwang, Jeong-Sun;Kang, Jin-Teak;Son, Yeong-Mo;Jeon, Hyun-Sun
    • Journal of Climate Change Research
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    • v.6 no.4
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    • pp.319-330
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    • 2015
  • This study was carried out to predict the optimal growth site and estimate carbon stocks of Quercus acuta, evergreen broad-leaved trees in warm temperate zone according to climate change. The criterion for the optimal site prediction was created by quantification method with quantitative and qualitative data, collected from growth factors of stands and environmental factors of survey sites of 42 plots in Q. acuta by study relationship between growth of tree and site environmental factors. A program for the optimal site prediction was developed by using GIS engine tools. To prediction of the suitable growth site of Quercus acuta, developed program in this study applied to Wando in Jeollanam-do, distributing a various evergreen bread-leaved trees of warm temperate zone. In the results from analysis of the optimal site prediction on Q. acuta, the characteristics of the optimal site showed as follows; site environmental features of class I (the best site class for Q. acuta) was defined as 401 ~ 500 m of altitude, $21{\sim}25^{\circ}$ of slope with above hillside, residual of deposit convex of slope type with west of aspect. The area and carbon stocks of optimal site prediction by class for Q. acuta in classI showed 147.1 ha (2.5%), total 316.5 tC/ha, total $1,161tCO_2/ha/yr$ of class I, 2,703.5 ha (46.3%), total 5,817.4 tC/ha, total $21,331tCO_2/ha/yr$ of class II, 2,845.5 ha (48.6%), total 6,123.0 tC/ha, total $2,845.5tCO_2/ha/yr$ of class III and 153.7 ha (2.6%), total 330.7 tC/ha, total $1,213.7tCO_2/ha/yr$ of class IV.

Topic Modeling of Profit Adjustment Research Trend in Korean Accounting (텍스트 마이닝을 이용한 이익조정 연구동향 토픽모델링)

  • Kim, JiYeon;Na, HongSeok;Park, Kyung Hwan
    • Journal of Digital Convergence
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    • v.19 no.1
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    • pp.125-139
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    • 2021
  • This study identifies the trend of Korean accounting researches on profit adjustment. We analyzed the abstract of accounting research articles published in Korean Citation Index (KCI) by using text mining technique. Among papers whose themes were profit adjustment, topics were divided into 4 parts: (i) Auditing and audit reports, (ii) corporate taxes and debt ratios, (iii) general management strategy of companies, and (iv) financial statements and accounting principles. Unlike the prediction that financial statements and accounting principles would be the main topic, auditing was analyzed as the most studied area. We analyzed topic trends based on the number of papers by topic, and could figure out the impact of K-IFRS introduction on profit adjustment research. By using Big Data method, this study enabled the division of research themes that have not been available in the past studies. This study enables the policy makers and business managers to learn about additional considerations in addition to accounting principles related to profit adjustment.