• Title/Summary/Keyword: Experimental Analysis

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Process Design of Carbon Dioxide Storage in the Marine Geological Structure: I. Comparative Analysis of Thermodynamic Equations of State using Numerical Calculation (이산화탄소 해양지중저장 처리를 위한 공정 설계: I. 수치계산을 통한 열역학 상태방정식의 비교 분석)

  • Huh, Cheol;Kang, Seong-Gil
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.11 no.4
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    • pp.181-190
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    • 2008
  • To response climate change and Kyoto protocol and to reduce greenhouse gas emissions, marine geological storage of $CO_2$ is regarded as one of the most promising option. Marine geological storage of $CO_2$ is to capture $CO_2$ from major point sources(eg. power plant), to transport to the storage sites and to store $CO_2$ into the marine geological structure such as deep sea saline aquifer. To design a reliable $CO_2$ marine geological storage system, it is necessary to perform numerical process simulation using thermodynamic equation of state. The purpose of this paper is to compare and analyse the relevant equations of state including ideal, BWRS, PR, PRBM and SRK equation of state. To evaluate the predictive accuracy of the equation of the state, we compared numerical calculation results with reference experimental data. Ideal and SRK equation of state did not predict the density behavior above $29.85^{\circ}C$, 60 bar. Especially, they showed maximum 100% error in supercritical state. BWRS equation of state did not predict the density behavior between $60{\sim}80\;bar$ and near critical temperature. On the other hand, PR and PRBM equation of state showed good predictive capability in supercritical state. Since the thermodynamic conditions of $CO_2$ reservoir sites correspond to supercritical state(above $31.1^{\circ}C$ and 73.9 bar), we conclude that it is recommended to use PR and PRBM equation of state in designing of $CO_2$ marine geological storage process.

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Studies on Estimation of Fish Abundance Using an Echo Sounder ( 1 ) - Experimental Verification of the Theory for Estimating Fish Density- (어군탐지기에 의한 어군량 추정에 관한 기초적 연구 ( 1 ) - 어군량추정이론의 검증실험 -)

  • 이대재
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.27 no.1
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    • pp.1-12
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    • 1991
  • An experiment has been carefully designed and performed to verify the theory for the echointergration technique of estimating the density of fish school by the use of steel spheres in a laboratory tank. The spheres used to simulate a fish school were randomly distributed throughout the insonified volume to produce the acoustic echoes similar to those scattered from real fish schools. The backscattered echoes were measured as a function of target density at tow frequencies of 50kHz and 200kHz. Data acquisition, processing and analysis were performed by means of the microcomputer-based sonar-echo processor including a FFT analyzer. Acoustic scattering characteristics of a 36cm mackerel was investigated by measuring fish echoes with frequencies ranging from 47.8kHz to 52.0kHz. The fluctuation of bottom echoes caused by the effects of fish-school attenuation and multiple scattering which occurred in dense aggregations of fishes was also examined by analyzing the echograms of sardine schools obtained by a 50kHz telesounder in the set-net's bagnet, and the echograms obtained by a scientific echo sounder of 50kHz in the East China Sea, respectively. The results obtained can be summarized as follows: 1. The measured and the calculated echo shapes on the steel sphere used to simulate a fish school were in close agreement. 2. The waveform and amplitude of echo signals by a mackerel without swimbladder fluctuated irregularly with the measuring frequency. 3. When a collection of 30 targets/m super(3) lied the shadow region behind another collection of 5 targets/m super(3), the mean losses in echo energy for the 30 targets/m super(3) were about -0.4dB at 50kHz and about -0.2dB at 200kHz, respectively. 4. In the echograms obtained in the East China Sea, the bottom echoes fluctuated remarkably when the dense aggregations of fish appeared between transducer and seabed. Especially, in the case of the echograms of sardine school obtained in a set-net's bagnet, the disappearance of bottom echoes and the lengthening of the echo trace by fish aggregations were observed. Then the mean density of the sardine school was estimated as 36 fish/m super(3). It suggests that when the distribution density of fishes in oceans is greater than this density, the effects of fish-school attenuation and multiple scattering must be taken into account as a possible source of error in fish abundance estimates. 5. The relationship between mean backscattering strength (, dB) and target density ($\rho$, No./m super(3)) were expressed by the equations: =-46.2+13.7 Log($\rho$) at 50kHz and =-43.9+13.4 Log($\rho$) at 200kHz. 6. The difference between the experimentally derived number and the actual number of targets gradually decreased with an increase in the target density and was within 20% when the density was 30 targets/m super(3). From these results, we concluded that when the number of targets in the insonified volume is large, the validity of the echo-integration technique of estimating the density of fish schools could be expected.

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Studies on Estimation of Fish Abundance Using an Echo Sounder ( 2 ) - The Relationship between Acoustic Backscattering Strength and Distribution Density of Fish in a Net Cage- (어군탐지기에 의한 어군량 추정에 관한 기초적 연구 ( 2 ) - 어군의 분포밀도와 초음파산란강도의 관계 -)

  • 이대재
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.27 no.1
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    • pp.13-20
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    • 1991
  • This paper describes the fish-density dependence of the mean backscattering strength with aggregations of encaged, free-swimming fish of known density in relation to the experimental verification of echo-integration technique for estimating the density of fish shoals. In this experiment, various numbers of gold crussian, Carassius burgeri burgeri, with a mean length of 18.5cm and a mean weight of 205.9g, were introduced into a net cage of approximately 0.76m super(3). During the backscattering measurements. the cage was suspended on the sound axis of the 50kHz transducer having a beam width of 33 degrees at -3dB downpoints. The volume backscattering strengths from fish aggregations were measured as a function of fish density. Data acquisition, processing and analysis were performed by means of the microcomputer-based sonar-echo processor including a FFT analyzer. The calibration of echo-sounder system was carried out at field with a steel ball bearing of 38mm in diameter having the target strength of -40.8dB. The dorsal-aspect target strengths on anesthetized specimens of gold crussian used in the cage experiment were measured and compared with the target strength predicted by the fish density-echo energy relationship for aggregations of free-swimming gold crussian in the cage. The results obtained can be summarized as follows: 1. The target strengths in the dorsal aspect on anesthetized specimens of gold crussian, with the mean length of 19.1cm and the mean weight of 210.5g, varied from -40.9dB to -44.8dB with a mean of -42.6dB. This mean target strength did not differ significantly from that predicted by the regression of echo energy on fish density of free-swimming gold crussian in the cage. It suggests that the target-strength measurements on anesthetized fish was valid and can be representative for live, free-swimming fish. 2. The relationship between mean backscattering strength(, dB) and distribution density of gold $crussian(\rho, $ fish/m super(3)) was expressed by the following equation; =-41.9+11 $Log(\rho)$ with a correlation coefficient of 0.97. This result support the existence of a linear relationship between fish density and echo energy, but suggest that this line has steeper slope than the regression by the theory of estimating the density of fish schools.

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Effects of Split Nitrogen Application on Growth Characters, Yield Potential and Feed Value in Jeju Italian Millet (제주조의 질소분시 횟수에 따른 생육반응, 수량성 및 사료가치 변화)

  • Cho, Nam-Ki;Kang, Young-Kil;Song, Chang-Kil;Ko, Dong-Hwan;Cho, Young-Il
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.23 no.1
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    • pp.37-42
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    • 2003
  • This study was conducted at a volcanic ash soil in the Experimental Farm of Cheju national university from May 1, 2000 to August 25, 2000 to determine the optimum frequency of split N application for. forage production of Jeju Italian millet(Setaria italica Beauvis). N .rate was applied with 200kg N/ha, and frequencies of the split application were 1. 2, 3, 4 and f times. Days to heading was 87 days in the N applied plot all at once, was delayed to 93 days at the five times split-applied plot. Plant height was the greatest (143cm) at the four times split-applied plot, but above o. below that was short. Leaf length, number of leaves and nodes were a similar tendency to plant height. SPAD(Soil Plant Analysis Development) reading values rose 34.3∼36.2 as N was split-applied from one to five times. Fresh forage, dry matter, crude Protein and TDN yield at the H split-applied to four times increased 33.08∼5l.50MT/ha, 9.94∼13.36MT/ha, 0.93∼1.70MT/ha and 5.06∼7.28MT/ha, respectively, but at the five tines split-applied plot decreased to 49.33MT/ha, 12.69MT/ha, 1.65MT/ha and 6.98 MT/ha, respectively. As the increasing of N split-applied. crude protein, crude fat NFE and TDN content increased 9.4∼13.0%, 1.5∼l.9%, 44.5∼45.5% and 50.9∼55.0%, respectively, whereas crude fiber and crude ash content decreased 35.3∼31.6% and 9.3∼8.3, respectively.

Kinetics and Mechanism of the Oxidation of Alcohols by C9H7NHCrO3Cl (C9H7NHCrO3Cl에 의한 알코올류의 산화반응에서 속도론과 메카니즘)

  • Park, Young-Cho;Kim, Young-Sik;Kim, Soo-Jong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.8
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    • pp.378-384
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    • 2018
  • $C_9H_7NHCrO_3Cl$ was synthesized by reacting $C_9H_7NH$ with chromium (VI) trioxide. The structure of the product was characterized by FT-IR (Fourier transform infrared) spectroscopy and elemental analysis. The oxidation of benzyl alcohol by $C_9H_7NHCrO_3Cl$ in various solvents showed that the reactivity increased with increasing dielectric constant(${\varepsilon}$) in the following order: DMF (N,N'-dimethylformamide) > acetone > chloroform > cyclohexane. The oxidation of alcohols was examined by $C_9H_7NHCrO_3Cl$ in DMF. As a result, $C_9H_7NHCrO_3Cl$ was found to be an efficient oxidizing agent that converts benzyl alcohol, allyl alcohol, primary alcohols, and secondary alcohols to the corresponding aldehydes or ketones (75%-95%). The selective oxidation of alcohols was also examined by $C_9H_7NHCrO_3Cl$ in DMF. $C_9H_7NHCrO_3Cl$ was the selective oxidizing agent of benzyl, allyl and primary alcohol in the presence of secondary ones. In the presence of DMF with an acidic catalyst, such as $H_2SO_4$, $C_9H_7NHCrO_3Cl$ oxidized benzyl alcohol (H) and its derivatives ($p-OCH_3$, $m-CH_3$, $m-OCH_3$, m-Cl, and $m-NO_2$). Electron donating substituents accelerated the reaction rate, whereas electron acceptor groups retarded the reaction rate. The Hammett reaction constant (${\rho}$) was -0.69 (308K). The observed experimental data were used to rationalize hydride ion transfer in the rate-determining step.

학교도서관 발전의 저해요인에 관한 실증적 고찰 -일학교장의 학교도서관에대한 인식을 중심으로-

  • 김남석;김정소
    • Journal of Korean Library and Information Science Society
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    • v.7
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    • pp.1-55
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    • 1980
  • It has been observed that the purpose of education is poorly coordinated with the school library. Consequently a healthy growth of the library has been very rare, and educational process has been rather inefficient. Therefore this study attempts to define the role of a school library and the necessasity of its growth, examine principals' concepts of the library, find out the adverse causes for its growth, and make some suggestions to rectify them. A questionnaire was designed to get information on the principals' conceptions about the nature and the role of a school library, a librarian, and adverse causes for the growth of the library. This study is largely based on the analysis of this questionnaire. The results of this study may be summarized as. follows: 1) The school library is not generally considered as the center of educational activities. It is rather variously regarded as a subsidiary organization for education, a place where reading materials are offered, a place where books are kept, or a reading room. 2) This was largely due to the misconceptions of the principals as to the true nature and the role of the school library. 3) The degrees of their misconceptions varied depending on the amount of their exposure to the library science. Those principals who studied library science more hours had better understanding of the library. 4) Although the principals showed rather much concern for the library, the school library was not up to the expectation largely due to their misconception of it. 5) Most of the principals felt that they needed more knowledge on library science to carry out their job. This feeling was stronger for those who spent more hours in a library science course. 6) Most of the principals wanted to offer a position for a dual function: a librarian and a teacher. This was largely due to their lack of knowledge as to the duties of a librarian-which were considered as secondary to the duties of a teacher. 7) The majority of the principals thought the librarians were not paid well enough, but some of the principals o n.0, pposed their pay raise. The former generally took more courses in library science than the latter. 8) Many principals agreed that the adverse causes for the growth of the school library originated from the regional or governmental school authorities. This seemed to indicate that the legal requirements for the library were inadequate and that there was no administrative organization to take care of the library. 9) Most of the principals considered the insufficient funds as the major reason for the present poor condition of the library. But considering the fact that some libraries are better equi n.0, pped that others, financial matter cannot be the deciding factor. It rather seemed that there is some serious problems in the current educational system. For further studies in this field and for the libraries to function properly, the following suggestions are made here: 1) The major adverse cause for the healthy growth of the school library was found in the misconceptions on the school library by the principals, and these misconceptions were largely due to their lack of knowledge. Therefore they should be given more o n.0, pportunities to take courses in library science. 2) The librarian should not be overburdened with other duties than what his job duly calls for, and they should be properly compensated for their own job. They should also be encouraged to grow as librarians. 3) Education itself should be improved so that the library becomes the center of learning. 4) An administrative department should be created to oversee the school libraries, and legal measures should be enacted for better school libraries. 5) Financial su n.0, pport should be provided for a period of time in order to upgrade the school library to a certain level. Finally it is strongly felt that more detailed and inclusive studies in this field should be carried on and further experimental studies should be done.

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Medicolegal Problems in Pediatric Area (소아과 영역에서 의료분쟁)

  • Kwon, Soo Jeong;Jang, Ji Young;Kim, Nam Su;Yum, Myung Kul;Seol, In Joon;Jung, Ku Won
    • Clinical and Experimental Pediatrics
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    • v.48 no.8
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    • pp.813-819
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    • 2005
  • Purpose : Medicolegal problems start when the patient asserts the mistake of doctor and doctor does not accept it. The purpose of this study is to assess the actual condition of medicolegal problems and to provide solutions of medicolegal problems in the pediatric field. Methods : There is not official statistical data about medicolegal problems in our country. We gathered data of legal insurance program of Korean Medical Association(KMA) and court cases and other fragmentary data. Results : Between 1981 and 1995, of total 2,338 cases reported to legal problem insurance program of KMA, most common ones were 748 cases of obstetrics and gynecology. Pediatric case was ranked at the 5th, 74 cases(3.1%). According to analysis of 41 medicolegal cases' after 1990, maltreatment of patient had the highest incidence of 14 cases, injection and medication were related to 12 cases, misdiagnosis was 9 cases, patient management were related to 4 cases, and others were 2 cases. The trial result of the medicolegal cases was that 31 cases were compensated, and 8 cases were defeated, and 2 cases were still in the process. Conclusion : The aspect of medical legal problem has the tendency of radicalism and systematization. This brings an economic destitution in the patient and gives damage to a doctor. In order to reduce medicolegal problem, doctor should offer a duty of explanation and efforts to his best to satisfy patient and endeavor to make an intimate doctor-patient relationship.

Clinical Study of Acute Pyogenic Osteomyelitis in Children (소아 급성 화농성 골수염의 임상적 고찰)

  • Park, Ji Sook;Yeom, Jeong Suk;Hwang, Sun Chul;Park, Eun Sil;Seo, Ji Hyun;Lim, Jae Young;Park, Chan Hoo;Woo, Hyang Ok;Youn, Hee Shang
    • Clinical and Experimental Pediatrics
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    • v.48 no.7
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    • pp.731-736
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    • 2005
  • Purpose : Acute pyogenic osteomyelitis is uncommon in children. Delayed diagnosis and inappropriate treatment are leading to growth failure and deformation. We review the clinical manifestations and treatment of acute osteomyelitis in children according to age. Methods : A retrospective analysis was made of 32 patients who underwent antibiotic management or operation between Aug 1989 and Dec 2003 for acute pyogenic osteomyelitis in age from 0 to 15 years old. Results : The study group was composed of 21 boys and 11 girls. The subjects were divided into four groups according to age : 0-1 yr(n=6), 1-5 yr(n=11), 6-10 yr(n=8), and 11-15 yr(n=7). Nineteen cases were diagnosed in Winter. Femur was the most common infected site(37.5%). There were no predisposing factor in 17 patients, and 7 of 15 patients had trauma history. Sepsis was important predisposing factor in neonates. The chief complaints were pain, swelling and fever. S. aureus(61%) is the most common organism. Twenty-nine patients were treated with operation and concomitant antibiotics. Two cases had sequelae in follow-up period : One is avascular necrosis of femur and the other is discrepancy of leg length. Conclusion : In our review, because of poor prognosis in septic neonates, we recommend to treat actively neonatal sepsis and prevent or detect osteomyelitis early. Because most of patients were diagnosed and treated in orthopedic surgery, the rate of operation was too high. So, protocol for further evaluation and management of acute osteomyelitis in pediatric patients were needed.

Human Leukocyte Antigen(HLA) Genotypes and Thyroid Autoimmunity in Korean Patients with Type 1 Diabetes (한국인 제 1형 당뇨병 환자들의 HLA 유전자형 및 자가면역성 갑상선 질환의 병발 양상)

  • Kang, So Young;Shin, Chung Ho;Yang, Sei Won;Park, Myoung Hee;Yu, Jeesuk
    • Clinical and Experimental Pediatrics
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    • v.48 no.6
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    • pp.624-633
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    • 2005
  • Purpose : This study analyzed the expression of HLA-DR and DQ genotypes and anti-thyroid autoantibodies[anti-thyroid peroxidase(TPO) and anti-thyroglobulin(TG) antibodies] in Korean patients with type 1 diabetes(T1DM) to investigate the susceptible HLA alleles to T1DM in Korea and the prevalence of thyroid autoantibodies and their significance for the development of thyroid disorders. Methods : A total of 59 Korean patients with type 1 diabetes[26 males, median age 13.7 years(range 5.7-29.9 years), diabetes duration 7.6 years(-1.7-22.5 years)] were enrolled in this study, and 200 healthy Koreans without a family history of diabetes were selected as a normal control for the comparison of HLA genotypes. Seventeen patients with anti-TPO or anti-TG were followed [median duration 3.96 years(1 day-10.7 years)] with measurement of anti-TPO, anti-TG, $T_3$, $T_4$ or free $T_4$, TSH levels and physical examinations. HLA-DR and DQ genotyping were done by PCR-SSO, PCR-SSCP, PCR-RFLP and PCR-SSP methods. Results : HLA analysis showed higher frequencies of HLA-DRB1*0301, *090102 and DQB1*0201, *030302 alleles, DRB1*0301/*090102, *090102/*090102 and DQB1 *0201/*030302, *030302/*030302, *0201/ *0302 genotypes in T1DM patients compared to controls(Pc<0.05). Fifteen(25.4 percent) had anti-TPO antibody, 12(20.3 percent) had anti-TG, 17(28.8 percent) had either autoantibody and 10(16.9 percent) had both autoantibodies. No clinical or subclinical hypothyroidism developed during follow-up after the first detection of anti-thyroid autoantibody. There was no significant correlation between thyroid autoimmunity and gender, onset age of T1DM, and diabetes duration, respectively(P>0.05). Conclusion : We thought this unique HLA-DR, DQ allele distribution might be an important factor for the low incidence of T1DM in Korea. And a high prevalence of thyroid autoantibodies in these populations suggests examinations of thyroid antibodies should be performed regularly. Optimal age for the initial screening and the frequency of re-screening for associated thyroid autoimmune diseases in T1DM remains to be determined through prospective follow-up.

Risk Factors for the Early Recognition of Cow's Milk Protein-induced Enterocolitis (우유 단백질 유발성 장염의 조기진단을 위한 위험인자)

  • Lee, Sung Hyuk;Choi, Seon Yun;Lee, Byung Cheol;Choi, Won Joung;Choe, Byung Kyu;Kim, Yeo Hyang;Kang, Una;Kam, Sin;Hwang, Jin-Bok
    • Clinical and Experimental Pediatrics
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    • v.48 no.9
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    • pp.991-997
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    • 2005
  • Purpose : Cow's milk protein-induced enterocolitis(CMPIE) is a symptom complex of vomiting and/or diarrhea caused by delayed hypersensitivity and may result in serious complications. This study was undertaken to identify high risk factors to facilitate the early recognition of CMPIE. Methods : We reviewed the data of 101 patients, aged 15 to 45 days, admitted due to vomiting and/or diarrhea between 2003 and 2004. After excluding 13 patients absolutely breast-fed and 2 patients transferred from other hospitals with the impression of CMPIE, the 86 study subjects were divided into three groups based on the underlying etiologies; CMPIE, infectious and non-infectious group. Results : CMPIE was diagnosed in 11 patients(12.8%). On admission, failure to gain weight(P=0.003), hypoalbuminemia(P=0.003), peripheral leukocytosis(P=0.015), and metabolic acidosis(P=0.014) were more significant in the CMPIE group than in the others. Multiple logistic regression analysis showed that the independent predictors of high risks for CMPIE were failure to gain weight <10 g/day(OR, 10.25[95% CI, 1.62-65.06]) and serum hypoalbuminemia <3.5 g/dL(OR, 9.18[95% CI, 1.69-49.74]). Cow's milk challenges were performed in the 11 CMPIE patients; vomiting(81.8%), abnormal stool test(80.0%), peripheral leukocyte count and absolute neutrophil count(ANC) increase(100.0%) (P<0.05), and enteropathy(100.0%). Conclusion : CMPIE is not a rare clinical disease in early infancy. The high risk factors of CMPIE were identified as follow : failure to gain weight below 10 g/day, hypoalbuminemia on admission and a rapid decrease during admission. Cow's milk challenge test with endoscopic duodenal biopsy was helpful to confirm CMPIE.