사출성형의 3차원 충전공정해석

최권일(Choi Kwon-il),구본흥(Koo Bon-Heung) 대한기계학회 2002 대한기계학회 기타 간행물 Vol.2002 No.11

아미노산을 이용한 망간 산화물 기공성 나노 구조의 합성 및 C3H8 가스에 대한 선택적 감응 특성

최권일 ( Kwon Il Choi ),이종흔 ( Jong Heun Lee ) 한국센서학회 2011 센서학회지 Vol.20 No.1

Porous manganese oxide porous nanostructures were prepared by amino-acid-mediated solvothermal self assembly reaction and subsequent heat treatment at 600 。C. When Mn-precursors were heat-treated at 400 - 550 。C, the sensors did not show significant gas responses. In contrast, the manganese oxide heat-treated at 600 。C showed the significant gas responses, that is, the resistance decrease to 100 ppm C3H8 (Ra/Rg = 2.17, Ra : resistance in air, Rg : resistance in gas) and the resistance increase to 100 ppm C2H5OH (Rg/Ra = 1.92). The opposite change of resistance upon exposure to C3H8 and C2H5OH was discussed in relation to the mixed phases of manganese oxides with different valences.

금속 산화물 반도체 나노구조의 합성과 가스 감응 특성

최권일,이종흔,Choi, Kwon-Il,Lee, Jong-Heun 한국전기전자재료학회 2012 전기전자재료학회논문지 Vol.25 No.8

The prepartion of various metal oxide nanostructures via hydrothermal method, hydrolysis, thermal evaporation and electrospinning and their applications to chemoresistive sensors have been investigated. Hierarchical and hollow nanostructures prepared by hydrothermal method and hydrolysis showed the high response and fast responding kinetics on account of their high gas accessibility. Thermal evaporation and electrospinning provide the facile routes to prepare catalyst-loaded oxide nanowires and nanofibers, respectively. The loading of noble metal and metal oxide catalyst were effective to achieve rapid response/recovery and selective gas detection.

패밀리금형에서의 수지 유변학적 특성에 따른 가변러너의 성능 분석

최권일,박형필,차백순,이병옥,구본흥,Choi, Kwon-Il,Park, Hyung-Pil,Cha, Baek-Soon,Lee, Byung-Ok,Gu, Bon-Heung 한국금형공학회 2008 한국금형공학회지 Vol.2 No.6

It is well known that the family-mold has an advantage to reduce the cost for production and mold. However, defects are frequently occurred by over packing the smaller volume cavity during molding, especially when the family-mold has a volumetric difference between two cavities. In this study, the cavity-filling imbalance was confirmed by the temperature and the pressure sensors, and a variable-runner system was developed for balancing the cavity-filling. Experiments of balancing the cavity filling was carried out in the family-mold with the variable-runner system, and balancing the cavity-filling was confirmed by changing the cross-sectional area of a runner in the variable-runner system with the temperature and pressure sensors. The influence of the injection speed to the balancing-capability of the variable-runner system was also examined in the experiment.

사출성형에서 Fast Multipole Method 를 이용한 금형냉각해석

구본흥(Bon-Heung Koo),최권일(Kwon-Il Choi) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.11

Mold cooling process in injection molding is critical in order to reduce cycle time and improve the quality of molded part. In this paper, a fully three-dimensional mold cooling analysis is developed. Mold heat transfer is considered as cyclic-steady, three-dimensional conduction: heat transfer within the part is treated as a three-dimensional transient heat conduction; heat exchange between the cooling channel surfaces and coolant is treated as a cycle-averaged steady state three-dimensional heat conduction. Numerical implementation includes the application of a hybrid scheme consisting of a 3D BEM based on FMM for mold region and a CVFEM for part. The FMM algorithm dramatically reduces the complexity of matrix-vector multiplication involving a certain type of dense matrix, which can arise out of many physical systems. The present analysis is then used to predict the temperature field for a 3D plastic part geometry.

이익공시의 적시성과 주가붕괴위험

강나라(제1저자) ( Na Ra Kang ),최권일(교신저자) ( Kwon Il Choi ),최관(공동저자) ( Kwan Choi ) 한국회계학회 2015 회계학연구 Vol.40 No.6

본 연구는 이익공시의 적시성에 따라 주가붕괴위험이 어떻게 다른가를 살펴보았다. 주가붕괴란 단기간 내에 극단적인 음(-)의 수익률이 발생하는 현상으로, 선행연구에서는 누적된 나쁜 뉴스(bad news)가 일시에 전달되는 것을 원인으로 지목해 왔다. 적시성과주가붕괴위험은 밀접한 관련이 있을 수 있다. 왜냐하면 나쁜 뉴스를 보류하려는 경영자의의도가 적시성에 영향을 주기 때문이다. 본 연구는 이익공시의 적시성을 이익보고시차(reporting delay)와 이익보고간격(reportinginterval)으로 구분하여 적시성과 주가붕괴위험과의 관련성을 살펴보았다. 두 가지 측정방법 모두 적시성의 수준이 높을수록 주가붕괴위험이 낮은 것으로 나타났다. 이러한 결과는 나쁜 뉴스의 전달을 보류하려는 경영자의 의도가 이익공시의 적시성에 반영됨을 의미한다. 추가분석으로 기업의 투명성과 관련된 적시성을 통제한 후 적시성 수준의 변화분과 주가붕괴위험과의 관련성을 살펴보았다. 왜냐하면 기업정보의 투명성의 수준에 따라 적시성 수준은 상당한 예측가능성을 가짐으로, 투명성과 관련된 적시성 수준을 통제한 후에도 주가붕괴위험과 관련성이 있는가를 살펴보기 위해서다. 추가분석결과, 투명성 수준을 통제한 후에도 적시성 수준이 높을수록 주가붕괴위험이 낮은 것으로 나타났다. 본 연구는 경영자의 의도가 적시성에 영향을 줌으로 적시성과 주가붕괴위험이 밀접한 관련성을 갖는다는 점을 밝혔다. 더 나아가 이익의 중요한 질적 속성 중의 하나인 적시성에 대한 이해를 넓혔다. 본 연구의 결과는 공시정책 담당자뿐만 아니라 투자자들에게도 시사하는 바가 클 것으로 기대된다. This study examines the association between timeliness of earnings announcement and stock price crash risk. Stock price crash risk is defined as the probability that the extreme negative return occurs in the short term period(DeFond et al. 2015). Prior researches report that stock price crash is more likely to happen when the accumulated bad news are released to investors at once(Jin and Myers 2006, Hutton et al. 2009, Francis et al. 2011, Kim and Zhang 2015). Also, opacity is one of the factors that cause stock price crash since firms with low transparency are more likely to cumulate bad news(Hutton et al. 2009). If the timeliness of earnings announcement is affected by both managers`` intention which is not to delivered bad news in a timely manner and firm-specific transparency level, then it should be associated with stock price crash risk. In this study, we proxy for crash risk with two measures: (i) the indicator variable that equals to one if a firm experiences one or more firm-specific weekly returns falling 3.2 or more standard deviations below the mean firm-specific weekly return for fiscal year and (ii) the negative skewness of firm-specific weekly returns. Earnings timeliness is influenced by manager``s intention to withhold bad news(Givoly and Palmon 1982, Patell and Wolfson 1982). Also, the timeliness of a firm``s earnings announcement is one of the factors to determine the firm-level transparency(Bushman et al. 2004). Therefore, we can expect that the timeliness of earnings announcement and stock price crash risk are closely related to each other. Generally, an improvement in reporting timeliness which include both reporting delay and reporting interval generates the positive value of financial reporting and provides more useful information. In our study, the reporting delay is measured by the period from the end of the fiscal year to earnings announcement day, and the reporting interval is measured by the frequency of voluntary earnings announcement following Feltham(1968). Total sample consists of 4,266 firm-year observations that are traded over Korea Exchange for the period 2004~2013 but the year of financial crisis period is excluded. Empirical evidences of our study show that the reporting delay and stock price crash risk have a significant and positive association. We also find that changes in reporting delay are significant and positively associated with stock price crash risk in all models after controlling for transparency that is related with timeliness using the last year``s reporting delay. We find that the frequency of voluntary earnings announcement is significantly and negatively associated with stock price crash risk. We take an additional analyses to examine the relation between frequency of voluntary earnings announcement and crash risk after controlling for firm-specific transparency levels that is related with frequency of voluntary earnings announcement. Additional tests yield that changes in voluntary earnings announcement are significantly and negatively associated with stock price crash risk after controlling for firm-specific transparency levels using last year`` reporting frequency. We could interpret this result as the voluntary reporting frequency reflects the manager``s intention to withhold bad news. This study contributes to the literatures as the below; First, this study explores the relation between timeliness of earnings announcement and stock price crash risk. Though timeliness is one of the important earning qualitative characteristics, up to the present, there is little empirical evidence to examine this relation. Generally, the prior literatures which explore stock price crash risk investigate the relation between earnings quality, such as conservatism and discretionary accruals, and stock price crash risk(Kim and Zhang 2015, Hutton et al. 2009). In contrast, this study explores the association between timeliness and stock price crash, it widens the understanding of the relationship between the stock price crash and the earning qualitative characteristics. Second, this study proves the positive relation between timeliness of earnings announcement and stock price crash risk which is caused by accumulation of bad news. We expect that the results of this study contribute to not only the persons in charge of disclosure but also investors.

연구논문 : 포괄손익계산서 보고양식과 회계이익의 정보유용성

박연희 ( Yeon Hee Park ),송인만 ( In Man Song ),최권일 ( Kwon Il Choi ) 한국회계학회 2015 회계저널 Vol.24 No.1

K-IFRS 하에서는 포괄손익계산서는 당기순손익과 기타포괄손익을 하나의 손익계산 서로 보고하는 단일보고방식과 따로 나누어 보고하는 분리보고방식 중 하나를 선택하여 작성할 수 있다. 그러나 최근에 IASB는 당기순손익과 기타포괄손익을 구분하는 명백한 원칙이 없고 이를 구분할만한 특성이 없으므로 단일보고방식만을 사용할 것을 제안하였다. 그러나 기업들은 당기순손익과 기타포괄손익의 성격이 근본적으로 같지 않고, 단일보고방식의 포괄손익계산서에서 당기순손익이 부적절하게 덜 강조될 수 있다고 주장하면서 단일보고방식만을 사용하는 것에 대해 반대하였다. 이에 따라 IASB는 두 가지 방식 모두 사용할수 있도록 허용하였으나, 이와 관련된 논의는 아직까지도 진행 중에 있다. 위와 같은 관점에서 본 연구는 두 가지의 목적을 가지고 수행되었다. 첫째는 경영자가 포괄손익계산서의 보고양식을 선택할 때 기타포괄손익을 고려하는 지를 검증하는 것이며, 둘째는 손익계산서 보고양식에 따라 동일한 이익을 시장에서 다르게 인식하는지 검증하는 것이다. 본 연구의 결과는 다음과 같다. 첫째, 우리나라 유가증권 상장 기업 중 약 81%의 기업이 단일보고방식을, 19%기업이 분리보고방식을 사용하고 있으며, 기타포괄손익이 크면 분리보고방식보다는 단일보고방식을 선호하는 것으로 나타났다. 둘째, 단일보고방식의 포괄손익이 분리보고방식의 포괄손익보다 정보유용성이 큰 것으로 나타났다. 셋째, 기타포괄손익이 아주 큰 음(-)의 값을 가질 때 분리보고방식의 당기순이익이 상대적으로 정보유용성이 큰것으로 나타났다. 이러한 본 연구의 결과는 음(-)의 값으로 아주 큰 기타포괄손익이 경영자의 손익계산서 보고방식과 투자자의 정보유용성에 영향을 미친다는 것을 의미한다. 본 연구는 분리보고양식의 포괄손익계산서를 사용하는 경영자들의 동기가 기타포괄손익의 크기에 따라 달라지는지 살펴보았으며, 이러한 연구결과는 IASB와 실무에서 아직까지 논쟁이 되고 있는 포괄손익계산서의 보고양식의 선택에 대한 해결방안을 제시할 수 있는 근거를 제시할 기대한다. Managers could choose income statement types: single statement type or consecutive two statements type under K-IFRS(International Financial Accounting Standards adopted by Korea). The IASB(International Accounting Standards Board) has allowed both types, but proposed recently the elimination of the option reporting OCI(other comprehensive income) in consecutive two statements because they think there are no clear principles nor special characteristics distinguishing OCI from net income components. However, Respondents to the proposal expressed a concern that a single statement would cause confusion among investors by inappropriately deemphasizing net income. They also argued that there would be fundamental differences between net income components and OCI, and that the proximity of these items in a same statement would blur these differences. Therefore, The IASB decided to keep allowing the option of consecutive two separate statements approach. However, IASB is still working on this issue under the Disclosure Initiative project. In general, managers would like to report higher net income and avoid to report losses. (Carslaw 1988; Thomas 1988; Hayn 1995; Burgstahler and Dichev 1997; Beatty and Petroni 2002; Song et al. 2004). Managers`` choice on a specific type of income statement can be explained by this behavior. In other words, managers’ choice depends on how users recognize profits, which could represent company``s performance. In Korea, we could not overlook the fact that Korean information users tend to fix their performance evaluation on income figures reported on an income statement because the accounting history of K-IFRS is relatively short. Therefore, traditional functional fixation hypothesis seems to be working relatively well. Users may be able to recognize a comprehensive income on a single statement, which is similar to the income statement format prior to newly adopted K-IFRS in Korea, as a company``s real profit because investor is likely to react mechanically(Hand 1990; Abdel-khalik and Keller 1979; Bloomfield and Libby 1995; Sloan 1996) under the traditional functional fixation hypothesis. Thus, manager may choose a income statement type wherein comprehensive income causes higher earnings or less losses on the report. On a single income statement, comprehensive income is reported as final earnings at the bottom and net income is shown up in the middle because the statement reports: (i) net income; (ii) other comprehensive income; (iii) comprehensive income, in a sequence. Thus, managers’ choice on report types is likely affected by the amount of other comprehensive income because comprehensive income is the sum of income and other comprehensive income. That is, the larger OCI, the larger the CI; but the larger the OCI losses(-), the lower the CI. Therefore, managers are likely to prefer a single comprehensive income statement when OCI is larger since it will report higher CI. The purpose of this study is as follows; First is to test whether managers may consider OCI when they choose income statement type; Second is to test whether stock market may respond differently even for same earnings reported on different type of income statements. Results of this study indicate that managers prefer single statement when OCI is larger. Also, usefulness of CI in a single statement is larger than the CI in consecutive two statements, and usefulness of net income is affected by OCI figures. That is, the usefulness of net income reported in a consecutive two statements is larger than that reported in a single statement when OCI is negative. The results also indicate that 81% of listed companies in KSE(Korean Stock Exchange) use a single statement and the others(19%) use a consecutive two-statement approach. Especially, managers prefer the consecutive two-statement approach when other comprehensive income is extremely negative(-). The results suggest that managers might choose income statement type, considering investors reactions. Unlike previous studies, this study examined not only managers`` behavior, but also investor`s reactions. That will be a possible contribution of our study. The outcomes of this study is expected to provide some tips to the ever continuing discussions on income statement types to be used in the future.

지방간에 대한 혈청 r-glutamyl transferase ( GGT ) 의 진단적 유용성 및 다른 인자와의 상관관계

최권(Kwon Choi),김병익(Byung Ik Kim),조용균(Yong Kyun Cho),박창영(Chang Young Park),손정일(Jung Il Sohn),전우규(Woo Kyu Jeon),김향(Hyang Kim),정을순(Eul Soon Chung),금동극(Dong Geuk Keum),이화영(Hwa Young Lee),이상종(Sang Jong Lee) 대한내과학회 1999 대한내과학회지 Vol.57 No.6

N/A Background : Gamma-glutamyl transferase(GGT) has found wide application as a diagnostic test in hepatobiliary disease, and has been used as the best single marker of alcohol intake. In spite of the wide use of GGT in clinical practice, knowledge concerning the distribution and the determinants of this risk factor in the normal population is spared in Korea. We tried to obtain a better evaluation of specificity of serum GGT by analysis of a large population of health examination. Methods : GGT was measured in 17,140 males aged 17-86 years and 12,125 females aged 18-90 years screened in a health survey program. Results : In multiple regression analyses, serum GGT level showed strong positive association with fatty liver, body mass index, serum levels of AST, ALT triglyceride, uric acid, alkaline phosphatase, systolic blood pressure, and diastolic blood pressure, and weakly positive association with serum levels of creatinine, total cholesterol, and fasting blood sugar. In females, menopause were positively associated with GGT. Conclusions : An elevated serum GGT levels is a strong indicator of hepatobiliary dysfunction or fatty liver. However, proper interpretation of a serum GGT elevation should be carefully considered in correlation with clinical data and laboratory findings. (Korean J Med 57:1006-1013, 1999)

Paclitaxel에 의해 유발된 피부경화증 1예

윤장혁 ( Jang Hyuk Yoon ),최권 ( Kwon Choi ),서현일 ( Hyun Il Seo ),이용수 ( Yong Su Lee ),오석중 ( Suk Joong Oh ),이승세 ( Seung Sei Lee ),조은윤 ( Eun Yoon Cho ) 대한내과학회 2006 대한내과학회지 Vol.70 No.2S

성인에서 진단된 신경아세포종 1예

배지철 ( Ji Cheul Pae ),최권 ( Kwon Choi ),서현일 ( Hyun Il Seo ),오석중 ( Suk Joong Oh ),김어진 ( Eo Jin Kim ),이승세 ( Seung Sei Lee ) 대한내과학회 2006 대한내과학회지 Vol.70 No.2S